files

Files promises are an umbrella for attributes of files. Operations fall basically into three categories: create, delete and edit.

    files:

      "/path/file_object"

          perms => perms_body,
          ... ;

Prior to version 3, file promises were scattered into many different types, including files, tidy, copy, and links. File handling in CFEngine 3 uses regular expressions everywhere for pattern matching. The old 'wildcard/globbing' expressions \* and ? are deprecated, and everything is based consistently on Perl Compatible Regular Expressions.

There is a natural ordering in file processing that obviates the need for the actionsequence. For example, the trick of using multiple actionsequence items with different classes.

    actionsequence = ( ... files.one  ..  files.two )

can now be handled more elegantly using bundles. The natural ordering uses that fact that some operations are mutually exclusive and that some operations do not make sense in reverse order. For example, editing a file and then copying onto it would be nonsense. Similarly, you cannot both remove a file and rename it.

File copying

Copying is 'backwards'. Instead of the default object being source and the option being the destination, in CFEngine 3 the destination is paramount and the source is an option. This is because the model of voluntary cooperation tells us that it is the object that is changed, which is the agent making the promise. One cannot force change onto a destination with CFEngine, one can only invite change from a source.

Normal ordering of promise attributes

CFEngine has no 'action sequence'. Ordering of operations has, in most cases, a natural ordering that is assumed by the agent. For example, 'delete then create' (normal ordering) makes sense, but 'create then delete' does not. This sort of principle can be extended to deal with all aspects of file promises.

The diagram below shows the ordering. Notice that the same ordering applies regardless of file type (plain-file or directory). Note also that file editing is done "atomically".

The pseudo-code for this logic is shown in the diagram and below:

 for each file promise-object
    {
    if (depth_search)
      do
        DepthSearch (HandleLeaf)
      else
        (HandleLeaf)
      done
    }

 HandleLeaf()
   {
   Does leaf-file exist?

     NO:  create
     YES: rename,delete,touch,

     do
      for all servers in {localhost, @(servers)}
         {
         if (server-will-provide)
            do
              if (depth_search)
                 embedded source-depth-search (use file source)
                 break
              else
                 (use file source)
                 break
              done
            done
         }
     done

   Do all links (always local)

   Check Permissions

   Do edits
   }

Depth searches (aka 'recursion') during searches

Recursion is called "depth-search", and CFEngine uses the 'globbing' symbols with standard regular expressions:

/one/.*/two/thr.*/four

When searching for hidden files (files with names starting with a '.') or files with specific extensions, you should take care to escape the dot (e.g., \.cshrc or .*\.txt) when you wish it to mean a literal character and not the any character interpretation provided by regular expression interpretation.

When doing a recursive search, the files '.' and '..' are never included in the matched files, even if the regular expression in the leaf_name specifically allows them.

The filename /dir/ect/ory/. is a special case used with the create attribute to indicate the directory named /dir/ect/ory and not any of the files under it. If you really want to specify a regular expression that matches any single-character filename, use /dir/ect/ory/[\w\W] as your promise regular expression (you can't use /dir/ect/ory/[^/], see below for an explanation.

Depth search refers to a search for file objects that starts from the one or more matched base-paths as shown in the example above.

Filenames and regular expressions

CFEngine allows regular expressions within filenames, but only after first doing some sanity checking to prevent some readily avoidable problems. The biggest rule you need to know about filenames and regular expressions is that all regular expressions in filenames are bounded by directory separators, and that each component expression is anchored between the directory separators. In other words, CFEngine splits up any file paths into its component parts, and then it evaluates any regular expressions at a component-level.

What this means is that the path /tmp/gar.* will only match filenames like /tmp/gar, /tmp/garbage and /tmp/garden. It will not match filename like /tmp/gar/baz; because even though the .* in a regular expression means "zero or more of any character", CFEngine restricts that to mean "zero or more of any character in a path component".

Correspondingly, CFEngine also restricts where you can use the / character. For example, you cannot use it in a character class like [^/] or in a parenthesized or repeated regular expression component.

This means that regular expressions that include "optional directory components" will not work. You cannot have a files promise to tidy the directory (/usr)?/tmp. Instead, you need to be more verbose and specify /usr/tmp|/tmp. Potentially more efficient would be a declarative approach. First, create an slist that contains both the strings /tmp and /usr/tmp and then allow CFEngine to iterate over the list.

This also means that the path /tmp/.*/something will match files such as /tmp/abc/something or /tmp/xyzzy/something. However, even though the pattern .* means "zero or more of any character (except /)", CFEngine matches files bounded by directory separators. So even though the pathname /tmp//something is technically the same as the pathname /tmp/something, the regular expression /tmp/.*/something will not match on the case of /tmp//something (or /tmp/something).

Promises involving regular expressions

CFEngine can only keep (or repair, or fail to keep) a promise on files which actually exist. If you make a promise based on a wildcard match, then the promise is only ever attempted if the match succeeds. However, if you make a promise containing a recursive search that includes a wildcard match, then the promise can be kept or repaired, provided that the directory specified in the promise exists. Consider the following two examples, which assume that there first exist files named /tmp/gar, /tmp/garbage and /tmp/garden. Initially, the two promises look like they should do the same thing; but there is a subtle difference:

bundle agent foobaz
{
files:
 "/tmp/gar.*"
    delete => tidy,
    classes => if_ok("done");
}

body classes if_ok(x)
{
  promise_repaired => { "$(x)" };
  promise_kept => { "$(x)" };
}

bundle agent foobaz
{
  files:
    "/tmp"
      delete => tidy,
      depth_search => recurse("0"),
      file_select => gars,
      classes => if_ok("done");
}

body file_select gars
{
leaf_name => { "gar.*" };
file_result => "leaf_name";
}

body classes if_ok(x)
{
  promise_repaired => { "$(x)" };
  promise_kept => { "$(x)" };
}

In the first example, when the configuration containing this promise is first executed, any file starting with "gar" that exists in the /tmp directory will be removed, and the done class will be set. However, when the configuration is executed a second time, the pattern /tmp/gar.* will not match any files, and that promise will not even be attempted (and, consequently the done class will not be set).

In the second example, when the configuration containing this promise is first executed, any file starting with "gar" that exists in the /tmp directory will also be removed, and the done class will also be set. The second time the configuration is executed, however, the promise on the /tmp directory will still be executed (because /tmp of course still exists), and the done class will be set, because all files matching the file_select attribute have been deleted from that directory.

Local and remote searches

There are two distinct kinds of depth search:

• A local search over promiser agents.
• A remote search over provider agents.

When we are copying or linking to a file source, it is the search over the remote source that drives the content of a promise (the promise is a promise to use what the remote source provides). In general, the sources are on a different device to the images that make the promises. For all other promises, we search over existing local objects.

If we specify depth search together with copy of a directory, then the implied remote source search is assumed, and it is made after the search over local base-path objects has been made. If you mix complex promise body operations in a single promise, this could lead to confusion about the resulting behavior, and a warning is issued. In general it is not recommended to mix searches without a full understanding of the consequences, but this might occasionally be useful.

Depth search is not allowed with edit_line promises.

Platform notes

Platforms that support named sockets (basically all Unix systems, but not Windows), may not work correctly when using a files promise to alter such a socket. This is a known issue, documented in this ticket.

Attributes

Common Attributes

Common attributes are available to all promise types. Full details for common attributes can be found in the Common Attributes section of the Promise Types and Attributes page. The common attributes are as follows:

action

classes

comment

depends_on

handle

ifvarclass

meta

with

acl

Type: body acl

Please note that for CFEngine versions before 3.7.5 and 3.10.0 (see this ticket) you need to specify a perms body or only the base directory will be considered. As a workaround, use the following perms body if you are not specifying one already, as suggested in that ticket:

body perms null_perms_body {
    ## Workaround for https://dev.cfengine.com/issues/4862
    ## Bug #4862: Recursive ACLs not working by default only with perms
    ##
    ## Dummy perms body is used as otherwise ACLs are not applied recursively
    rxdirs => "true";
}

See also: Common Body Attributes

aces

Description: Native settings for access control entry are defined by 'aces'. POSIX ACL are available in CFEngine Community starting with 3.4.0. NTFS ACL are available in with CFEngine Enterprise.

Type: slist

Allowed input range: ((user|group):[^:]+:[-=+,rwx()dtTabBpcoD]*(:(allow|deny))?)|((all|mask):[-=+,rwx()]*(:(allow|deny))?)

Form of the permissions is as follows:

                aces = {
                        "user:uid:mode[:perm_type]", ...,
                        "group:gid:mode[:perm_type]", ...,
                        "all:mode[:perm_type]"
                        };

• user

  A valid username identifier for the system and cannot be empty. However, user can be set to * as a synonym for the entity that owns the file system object (e.g. user:*:r).

  Notes:

  • The user id is not a valid alternative.
  • This ACL is required when acl_method is set to overwrite.

• uid

  A valid user identifier for the system and cannot be empty. However, uid can be set to * as a synonym for the entity that owns the file system object (e.g. user:*:r).

  Note: The username is not a valid alternative.

• group

  A valid group identifier for the system and cannot be empty. However, group can be set to * as a synonym for the group that owns the POSIX file system object (group:*:rwx).

  Notes:

  • The group id is not a valid alternative.
  • This ACL is required when acl_method is set to overwrite.

• gid

  A valid group identifier for the system and cannot be empty. However, in some ACL types, gid can be set to * to indicate a special group (e.g. in POSIX this refers to the file group).

  Note: The group name is not a valid alternative.

• all

  Indicates that the line applies to every user.

  Note: This ACL is required when acl_method is set to overwrite.

• mask

  A valid mask identifier (e.g. mask:rwx ). In essence the mask is an upper bound of the permissions that any entry in the group class will grant. When acl_method is overwrite if mask is not supplied, it will default to mask:rwx).

• mode

  One or more strings op|perms|(nperms); a concatenation of op, perms and optionally (nperms) separated with commas (e.g. +rx,-w(s) ). mode is parsed from left to right.

• op

  Specifies the operation on any existing permissions, if the defined ACE already exists. op can be =, empty, + or -. = or empty sets the permissions to the ACE as stated. + adds and - removes the permissions from any existing ACE.

• nperms (optional)

  Specifies file system specific (native) permissions. Only valid if acl_type is defined and will only be enforced if the file object is stored on a file system supporting this ACL type. For example, nperms will be ignored if acl_type:ntfs and the object is stored on a file system not supporting NTFS ACLs. Valid values for nperms varies with different ACL types. When acl_type is set to ntfs, the valid flags and their mappings is as follows:

  CFEngine nperm flag	NTFS Special Permission
  x	Execute File / Traverse Folder
  r	Read Data / List Folder
  t	Read Attributes
  T	Read Extended Attributes
  w	Write Data / Create Files
  a	Append Data / Create Folders
  b	Write Attributes
  B	Write Extended Attributes
  D	Delete Sub-folders and Files
  d	Delete
  p	Read Permissions
  c	Change Permissions
  o	Take Ownership

• perm_type (optional)

  Can be set to either allow or deny, and defaults to allow. deny is only valid if acl_type is set to an ACL type that support deny permissions. A deny ACE will only be enforced if the file object is stored on a file system supporting the acl type set in acl_type.

• gperms (generic permissions)

  A concatenation of zero or more of the characters shown in the table below. If left empty, none of the permissions are set.

  Flag	Description	Semantics on file	Semantics on directory
  r	Read	Read data, permissions, attributes	Read directory contents, permissions, attributes
  w	Write	Write data	Create, delete, rename subobjects
  x	Execute	Execute file	Access subobjects

  Notes

  • The r permission is not necessary to read an object's permissions and attributes in all file systems. For example, in POSIX, having x on its containing directory is sufficient.
  • Capital X which is supported by the setfacl command is not supported by the acl library, and thus not supported by the acl body.

Example:

body acl template
{
acl_method => "overwrite";
acl_type => "posix";
acl_default => "access";

aces => {
        "user:*:r(wwx),-r:allow",
        "group:*:+rw:allow",
        "mask:x:allow",
        "all:r"
        };
}

acl_default

Description: The access control list type for the affected file system is determined by acl_default.

Directories have ACLs associated with them, but they also have the ability to inherit an ACL to sub-objects created within them. POSIX calls the former ACL type "access ACL" and the latter "default ACL", and we will use the same terminology.

The constraint acl_default gives control over the default ACL of directories. The default ACL can be left unchanged (nochange), empty (clear), or be explicitly specified (specify). In addition, the default ACL can be set equal to the directory's access ACL (access). This has the effect that child objects of the directory gets the same access ACL as the directory.

Type: (menu option)

Allowed input range:

    nochange
    access
    specify
    clear

Example:

     body acl template

     {
     acl_method => "overwrite";
     acl_type => "posix";
     acl_default => "access";

     aces => {
             "user:*:rwx:allow",
             "group:*:+rw:allow",
             "mask:rx:allow",
             "all:r"
             };
     }

History: Was introduced in 3.5. Replaces the now deprecated acl_directory_inherit.

acl_inherit

Description: Defines whether the object inherits its ACL from its parent.

Type: (menu option)

Allowed input range:

• true
• false
• yes
• no
• on
• off
• nochange

Notes: This attribute has an effect only on Windows.

acl_method

Description: The acl_method menu option defines the editing method for an access control list.

When defining an ACL, we can either use an existing ACL as the starting point, or state all entries of the ACL. If we just care about one entry, say that the superuser has full access, the method constraint can be set to append, which is the default. This has the effect that all the existing ACL entries that are not mentioned will be left unchanged. On the other hand, if method is set to overwrite, the resulting ACL will only contain the mentioned entries.

Note: When acl_method is set to overwrite the acl must include the system owner, group and all. For example user:*:rwx, group:*:rx, and all:---.

Type: (menu option)

Allowed input range:

    append
    overwrite

Example:

     body acl template

     {
     acl_method => "overwrite";
     acl_type => "posix";
     aces => { "user:*:rw:allow", "group:*:+r:allow", "all:"};
     }

acl_type

Description: The acl_type menu option defines the access control list type for the affected file system.

ACLs are supported on multiple platforms, which may have different sets of available permission flags. By using the constraint acl_type, we can specify which platform, or ACL API, we are targeting with the ACL.

The default, generic, is designed to work on all supported platforms. However, if very specific permission flags are required, like Take Ownership on the NTFS platform, we must set acl_type to indicate the target platform. Currently, the supported values are posix and ntfs.

Type: (menu option)

Allowed input range:

    generic
    posix
    ntfs

Example:

     body acl template

     {
     acl_type => "ntfs";
     aces => { "user:Administrator:rwx(po)", "user:Auditor:r(o)"};
     }

specify_default_aces

Description: The slist specify_default_aces specifies the native settings for access control entry.

specify_default_aces (optional) is a list of access control entries that are set on child objects. It is also parsed from left to right and allows multiple entries with same entity-type and id. Only valid if acl_default is set to specify.

This is an ACL which makes explicit setting for the acl inherited by new objects within a directory. It is included for those implementations that do not have a clear inheritance policy.

Type: slist

Allowed input range: ((user|group):[^:]+:[-=+,rwx()dtTabBpcoD]*(:(allow|deny))?)|((all|mask):[-=+,rwx()]*(:(allow|deny))?)

Example:

     body acl template
     {
     specify_default_aces => {  "all:r" };
     }

changes

Type: body changes

See also: Common Body Attributes

hash

Description: The hash menu option defines the type of hash used for change detection.

The best option cross correlates the best two available algorithms known in the OpenSSL library.

Type: (menu option)

Allowed input range:

    md5
    sha1
    sha224
    sha256
    sha384
    sha512
    best

Example:

     body changes example
     {
     hash => "md5";
     }

report_changes

Description: Specify criteria for change warnings using the report_changes menu option.

Files can change in permissions and contents, i.e. external or internal attributes. If all is chosen all attributes are checked.

Type: (menu option)

Allowed input range:

    all
    stats
    content
    none

Example:

     body changes example
     {
     report_changes => "content";
     }

update_hashes

Description: Use of update_hashes determines whether hash values should be updated immediately after a change.

If this is positive, file hashes should be updated as soon as a change is registered so that multiple warnings are not given about a single change. This applies to addition and removal too.

Type: boolean

Example:

     body changes example
     {
     update_hashes => "true";
     }

report_diffs

This feature requires CFEngine Enterprise.

Description: Setting report_diffs determines whether to generate reports summarizing the major differences between individual text files.

If true, CFEngine will log a 'diff' summary of major changes to the files. It is not permitted to combine this promise with a depth search, since this would consume a dangerous amount of resources and would lead to unreadable reports.

The feature is intended as a informational summary, not as a version control function suitable for transaction control. If you want to do versioning on system files, you should keep a single repository for them and use CFEngine to synchronize changes from the repository source. Repositories should not be used to attempt to capture random changes of the system.

Limitations: Diffs will not be reported for files that are larger than 80MB in size. Diffs will not be reported if the number of lines between the first and last change exceed 4500. Diffs for binary files are not generated. Files are considered binary files if control character 0-32 excluding 9, 10, 13, and 32, or 127 are found in the file.

Type: boolean

Example:

     body changes example
     {
     report_diffs => "true";
     }

copy_from

Type: body copy_from

The copy_from body specifies the details for making remote copies.

Note: For improved performance, connections from cf-agent to cf-serverd are re-used. Currently connection caching is done per pass in each bundle activation.

See also: Common Body Attributes

source

Description: The source string represents the reference source file from which to copy. For remote copies this refers to the file name on the remote server.

Type: string

Allowed input range: .+

Example:

     body copy_from example
     {
     source => "/path/to/source";
     }

servers

Description: The servers slist names servers in order of preference from which to copy. The servers are tried in order until one of them succeeds.

Type: slist

Allowed input range: [A-Za-z0-9_.:-]+

Example:

     body copy_from example
     {
     servers => { "primary.example.org", "secondary.example.org",
                      "tertiary.other.domain" };
     }

collapse_destination_dir

Description: Use collapse_destination_dir to flatten the directory hierarchy during copy. All the files will end up in the root destination directory.

Under normal operations, recursive copies cause CFEngine to track subdirectories of files. So, for instance, if we copy recursively from src to dest, then src/subdir/file will map to dest/subdir/file.

By setting this option to true, the promiser destination directory promises to aggregate files searched from all subdirectories into itself; in other words, a single destination directory. So src/subdir/file will map to dest/file for any subdir.

Type: boolean

Example:

     body copy_from mycopy(from,server)
     {
     source      => "$(from)";
     servers     => { "$(server)" };
     collapse_destination_dir => "true";
     }

compare

Description: The menu option policy compare is used for comparing source and image file attributes.

The default copy method is mtime (modification time) or ctime (change time), meaning that the source file is copied to the destination (promiser) file, if the source file has been modified (content, permissions, ownership, moved to a different file system) more recently than the destination. Note this is special behavior when no comparison is specified as generally only a single comparison can be used.

Type: (menu option)

Allowed input range:

• mtime

CFEngine copies the file if the modification time of the source file is more recent than that of the promised file

• ctime

CFEngine copies the file if the creation time of the source file is more recent than that of the promised file

• atime

CFEngine copies the file if the modification time or creation time of the source file is more recent than that of the promised file. If the times are equal, a byte-for-bye comparison is done on the files to determine if it needs to be copied.

• exists

CFEngine copies the file if the promised file does not already exist.

• binary

CFEngine copies the file if they are both plain files and a byte-for-byte comparison determines that they are different. If both are not plain files, CFEngine reverts to comparing the mtime and ctime of the files. If the source file is on a different machine (e.g. network copy), then hash is used instead to reduce network bandwidth.

• hash

CFEngine copies the file if they are both plain files and a message digest comparison indicates that the files are different. In Enterprise versions of CFEngine version 3.1.0 and later, SHA256 is used as a message digest hash to conform with FIPS; in older Enterprise versions of CFEngine and all Community versions, MD5 is used.

• digest a synonym for hash

Default value: mtime or ctime differs

Example:

     body copy_from example
     {
     compare => "digest";
     }

copy_backup

Description: Menu option policy for file backup/version control

Determines whether a backup of the previous version is kept on the system. This should be viewed in connection with default_repository in body agent control, since a defined repository affects the location at which the backup is stored.

Type: (menu option)

Allowed input range:

    true
    false
    timestamp

Default value: true

Example:

body copy_from example
{
  copy_backup => "timestamp";
}

See also: Common Body Attributes, default_repository in body agent control, edit_backup in body edit_defaults

encrypt

Description: The encrypt menu option policy describes whether to use encrypted data stream to connect to remote hosts.

Client connections are encrypted with using a Blowfish randomly generated session key. The initial connection is encrypted using the public/private keys for the client and server hosts.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     servers  => { "remote-host.example.org" };
     encrypt => "true";
     }

Note: When used with protocol_version 2 or greater this attribute is a noop as the entire session is encrypted.

See also: protocol_version, ifencrypted, protocol_version, tls_ciphers, tls_min_version, allowciphers, allowtlsversion

check_root

Description: The check_root menu option policy checks permissions on the root directory when copying files recursively by depth_search.

This flag determines whether the permissions of the root directory should be set from the root of the source. The default is to check only copied file objects and subdirectories within this root (false).

Type: boolean

Example:

     body copy_from example
     {
     check_root => "true";
     }

copylink_patterns

Description: The copylink_patterns slist of patterns are matching files that should be copied instead of linked.

The matches are performed on the last node of the filename; in other words, the file without its path. As Windows does not support symbolic links, this feature is not available there.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body copy_from example
     {
     copylink_patterns => { "special_node1", "other_node.*" };
     }

copy_size

Description: The integers specified in copy_size determines the range for the size of files that may be copied.

The use of the irange function is optional. Ranges may also be specified as comma separated numbers.

Type: irange[int,int]

Allowed input range: 0,inf

Default value: any size range

Example:

     body copy_from example
     {
     copy_size => irange("0","50000");
     }

findertype

Description: The findertype menu option policy describes the default finder type on MacOSX.

This applies only to the Mac OS X variants.

Type: (menu option)

Allowed input range:

    MacOSX

Example:

     body copy_from example
     {
     findertype => "MacOSX";
     }

linkcopy_patterns

Description: The linkcopy_patterns contains patterns for matching files that should be replaced with symbolic links.

The pattern matches the last node filename; in other words, without the absolute path. Windows only supports hard links.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body copy_from mycopy(from)
     {
     source            => "$(from)";
     linkcopy_patterns => { ".*" };
     }

See Also: link_type.

link_type

Description: The link_type menu option policy contains the type of links to use when copying.

Users are advised to be wary of 'hard links' (see Unix manual pages for the ln command). The behavior of non-symbolic links is often precarious and unpredictable. However, hard links are the only supported type by Windows.

Note that symlink is synonymous with absolute links, which are different from relative links. Although all of these are symbolic links, the nomenclature here is defined such that symlink and absolute are equivalent. When verifying a link, choosing 'relative' means that the link must be relative to the source, so relative and absolute links are mutually exclusive.

Type: (menu option)

Allowed input range:

    symlink
    hardlink
    relative
    absolute

Default value: symlink

Example:

     body copy_from example
     {
     link_type => "symlink";
     source => "/tmp/source";
     }

missing_ok

Description: Treat a missing source file as a promise kept.

This allows you to override the promise outcome when a source file is missing. When set to true if the promise is a remote copy and there is a failure to connect the promise will not be considered kept. If the agent is able to request the file and the file is missing the promise will be kept.

Type: boolean

Default value: false

Example:

bundle agent main
{
  files:
    "/tmp/copied_from_missing_ok"
      copy_from => missing_ok( "/var/cfengine/masterfiles/missing" ),
      classes => results("bundle", "copy_from_missing_ok");

  reports:
    "$(with)"
      with => string_mustache( "", sort( classesmatching( "copy_from_.*" ), lex));
}
body copy_from missing_ok( file_path )
{
  source => "$(file_path)";
  missing_ok => "true";

    # Run with these classes to try remote copies
    remote_copy_self::
        servers => { "127.0.0.1" };

    remote_copy_policy_hub::
        servers => { $(sys.policy_hub) };
}
body classes results(scope, class_prefix)
{
  scope => "$(scope)";

  promise_kept => { "$(class_prefix)_reached",
                    "$(class_prefix)_kept" };

  promise_repaired => { "$(class_prefix)_reached",
                        "$(class_prefix)_repaired" };

  repair_failed => { "$(class_prefix)_reached",
                     "$(class_prefix)_error",
                     "$(class_prefix)_not_kept",
                     "$(class_prefix)_failed" };

  repair_denied => { "$(class_prefix)_reached",
                     "$(class_prefix)_error",
                     "$(class_prefix)_not_kept",
                     "$(class_prefix)_denied" };

  repair_timeout => { "$(class_prefix)_reached",
                      "$(class_prefix)_error",
                      "$(class_prefix)_not_kept",
                      "$(class_prefix)_timeout" };
}

In the above example /tmp/copied_from_missing_ok promises to be a copy of the local file /var/cfengine/masterfiles/missing. In the missing_ok copy_from body missing_ok is set to true. This causes the promise to be considered kept if the source file is missing. The results classes body is used to define bundle scoped classes prefixed with copy_from_missing_ok. The reports promise outputs a sorted list of the classes defined starting with copy_from_.

R: [
  "copy_from_missing_ok_kept",
  "copy_from_missing_ok_reached"
]

We can see in the output that the class defined for copying a local file that does not exist is seen to be a promise kept.

This policy can be found in /var/cfengine/share/doc/examples/missing_ok.cf and downloaded directly from github.

Notes:

This can be useful for opportunistically coping files that are not necessarily required or available at all times. For example if there is a host specific data that each host attempts to copy this will allow you to not have many promise failures when a host does not have any data prepared for it.

See also: seed_cp in the MPF, compare in body copy_from

History:

• Introduced in 3.12.0

force_update

Description: The force_update menu option policy instructs whether to always force copy update.

Warning: this is a non-convergent operation. Although the end point might stabilize in content, the operation will never quiesce. Use of this feature is not recommended except in exceptional circumstances since it creates a busy-dependency. If the copy is a network copy, the system will be disturbed by network disruptions.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     force_update => "true";
     }

force_ipv4

Description: The force_ipv4 menu option policy can determine whether to use ipv4 on an ipv6 enabled network.

IPv6 should be harmless to most users unless you have a partially or mis-configured setup.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     force_ipv4 => "true";
     }

portnumber

Description: Setting portnumber determines the port number to connect to on a server host.

The standard or registered port number is tcp/5308. CFEngine does not presently use its registered udp port with the same number, but this could change in the future.

Type: int

Allowed input range: 1,65535

Example:

     body copy_from example
     {
     portnumber => "5308";
     }

preserve

Description: Setting the preserve menu option policy determines whether to preserve file permissions on copied files.

This ensures that the destination file (promiser) gets the same file permissions as the source. For local copies, all attributes are preserved, including ACLs and SELinux security contexts. For remote copies, only Unix mode is preserved.

Note: This attribute will not preserve ownership (user/group).

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     preserve => "true";
     }

History: Version 3.1.0b3,Nova 2.0.0b1 (2010)

protocol_version

Description: Defines the protocol to use for the outgoing connection in this copy operation.

Type: (menu option)

Allowed input range:

• 0
• undefined
• 1
• classic
• 2
• latest

Default value: classic

Note: The value here will override the setting from body common control.

See also: protocol_version in body common, allowlegacyconnects

History: Introduced in CFEngine 3.6.0

purge

Description: The purge menu option policy instructs on whether to purge files on client that do not match files on server when a depth_search is used.

Purging files is a potentially dangerous matter during a file copy it implies that any promiser (destination) file which is not matched by a source will be deleted. Since there is no source, this means the file will be irretrievable. Great care should be exercised when using this feature.

Note this attribute only works when combined with depth_search and purging will also delete backup files generated during the file copying if copy_backup is set to true.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     purge => "true";
     }

stealth

Description: Setting the stealth menu option policy determines whether to preserve time stamps on copied files. This preserves file access and modification times on the promiser files.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     stealth => "true";
     }

timeout

Description: The integer set in timeout is the value for the connection timeout, in seconds.

Type: int

Allowed input range: 1,3600

Default Value: default_timeout

Example:

     body copy_from example
     {
     timeout => "10";
     }

See Also: agent default_timeout, cf-runagent timeout

Notes:

• cf-serverd will time out any transfer that takes longer than 10 minutes (this is not currently tunable).

trustkey

Description: The trustkey menu option policy determines whether to trust public keys from a remote server, if previously unknown.

If the server's public key has not already been trusted, trustkey provides automated key-exchange.

Note that, as a simple security precaution, trustkey should normally be set to false. Even though the risks to the client low, it is a good security practice to avoid key exchange with a server one is not one hundred percent sure about. On the server-side however, trust is often granted to many clients or to a whole network in which possibly unauthorized parties might be able to obtain an IP address. Thus the trust issue is most important on the server side.

As soon as a public key has been exchanged, the trust option has no effect. A machine that has been trusted remains trusted until its key is manually revoked by a system administrator. Keys are stored in WORKDIR/ppkeys.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     trustkey => "true";
     }

type_check

Description: The type_check menu option policy compares file types before copying.

File types at source and destination should normally match in order for updates to overwrite them. This option allows this checking to be switched off.

Type: boolean

Example:

     body copy_from example
     {
     type_check => "false";
     }

verify

Description: The verify menu option policy instructs whether to verify transferred file by hashing after copy.

Warning: This is a highly resource intensive option, and is not recommended for large file transfers.

Type: boolean

Default value: false

Example:

     body copy_from example
     {
     verify => "true";
     }

create

Description: true/false whether to create non-existing file

Directories are created by using the /. to signify a directory type. Note that, if no permissions are specified, mode 600 is chosen for a file, and mode 755 is chosen for a directory. If you cannot accept these defaults, you should specify permissions.

Note that technically, /. is a regular expression. However, it is used as a special case meaning "directory". See filenames and regular expressions for a more complete discussion.

Type: boolean

Default value: false

Example:

files:

  "/path/plain_file"

     create =>   "true";

  "/path/dir/."

     create =>   "true";

Note: In general, you should not use create with copy_from or link_from in files promises. These latter attributes automatically create the promised file, and using create may actually prevent the copy or link promise from being kept (since create acts first, which may affect file comparison or linking operations).

delete

Type: body delete

See also: Common Body Attributes

dirlinks

Description: Menu option policy for dealing with symbolic links to directories during deletion

Links to directories are normally removed just like any other link or file objects. By keeping directory links, you preserve the logical directory structure of the file system, so that a link to a directory is not removed but is treated as a directory to be descended into.

The value keep instructs CFEngine not to remove directory links. The values delete and tidy are synonymous, and instruct CFEngine to remove directory links.

Type: (menu option)

Allowed input range:

    delete
    tidy
    keep

Example:

     body delete example
     {
     dirlinks => "keep";
     }

Default value (only if body is present): dirlinks = delete

The default value only has significance if there is a delete body present. If there is no delete body then files (and directory links) are not deleted.

rmdirs

Description: true/false whether to delete empty directories during recursive deletion

Type: boolean

Example:

     body delete example
     {
     rmdirs => "true";
     }

Note the parent directory of a search is not deleted in recursive deletions. You must code a separate promise to delete the single parent object. For an example see bundle agent rm_rf_depth in the standard library.

Default value (only if body is present): rmdirs = true

The default value only has significance if there is a delete body present. If there is no delete body then files (and directories) are not deleted.

depth_search

Type: body depth_search

See also: Common Body Attributes

depth

Description: Maximum depth level for search

When searching recursively from a directory, the parent directory is only the anchor point and is not part of the search. To alter the parent, a separate non-recursive promise should be made.

Type: int

Allowed input range: 0,99999999999

Note that the value inf may be used for an unlimited value.

Example:

     body depth_search example
     {
     depth => "inf";
     }

exclude_dirs

Description: List of regexes of directory names NOT to include in depth search

Directory names are treated specially when searching recursively through a file system.

Type: slist

Allowed input range: .*

Example:

     body depth_search
     {
     # no dot directories
     exclude_dirs => { "\..*" };
     }

include_basedir

Description: true/false include the start/root dir of the search results

When checking files recursively (with depth_search) the promiser is a directory. This parameter determines whether that initial directory should be considered part of the promise or simply a boundary that marks the edge of the search. If true, the promiser directory will also promise the same attributes as the files inside it.

Type: boolean

Example:

     body depth_search example
     {
     include_basedir => "true";
     }

include_dirs

Description: List of regexes of directory names to include in depth search

This is the complement of exclude_dirs.

Type: slist

Allowed input range: .*

Example:

     body depth_search example
     {
     include_dirs => { "subdir1", "subdir2", "pattern.*" };
     }

rmdeadlinks

Description: true/false remove links that point to nowhere

A value of true determines that links pointing to files that do not exist should be deleted; or kept if set to false.

Type: boolean

Default value: false

Example:

     body depth_search example
     {
     rmdeadlinks => "true";
     }

traverse_links

Description: true/false traverse symbolic links to directories

If this is true, cf-agent will treat symbolic links to directories as if they were directories. Normally this is considered a potentially dangerous assumption and links are not traversed.

Type: boolean

Default value: false

Example:

     body depth_search example
     {
     traverse_links => "true";
     }

xdev

Description: When true files and directories on different devices from the promiser will be excluded from depth_search results.

Type: boolean

Default value: false

Example:

body depth_search example
{
  xdev => "true";
}

edit_defaults

Type: body edit_defaults

See also: Common Body Attributes

edit_backup

Description: Menu option for backup policy on edit changes

Type: (menu option)

Allowed input range:

    true
    false
    timestamp
    rotate

Default value: true

Example:

A value of true (the default behavior) will result in the agent retaining the previous version of the file suffixed with .cf-before-edit.

body edit_defaults backup( edit_backup )
{
  edit_backup => "$(edit_backup)";
}

bundle agent main
{
  files:
    "/tmp/example_edit_backup_true"
      create => "true";

    "/tmp/example_edit_backup_true"
      edit_line => insert_lines("Hello World"),
      edit_defaults => backup("true");

  vars:
    "example_files" slist => sort(lsdir( "/tmp/", "example_edit_backup_true.*", false), lex);

  reports:
    "$(example_files)";
}

Outputs:

R: example_edit_backup_true
R: example_edit_backup_true.cf-before-edit

A value of timestamp will result in the original file be suffixed with the epoch and the canonified form of the date when the file was changed followed by .cf-before-edit. For example _1511292441_Tue_Nov_21_13_27_22_2017.cf-before-edit.

body edit_defaults backup( edit_backup )
{
  edit_backup => "$(edit_backup)";
}

bundle agent main
{
  files:
    "/tmp/example_edit_backup_timestamp"
      create => "true";

    "/tmp/example_edit_backup_timestamp"
      edit_line => insert_lines("Hello World"),
      edit_defaults => backup("timestamp");

  vars:
    "example_files" slist => lsdir( "/tmp/", "example_edit_backup_timestamp.*", false);

  reports:
    "$(example_files)";
}

Outputs:

R: example_edit_backup_timestamp
R: example_edit_backup_timestamp_1511300904_Tue_Nov_21_15_48_25_2017.cf-before-edit

A value of false will result in no retention of the original file.

A value of rotate will result in the original file be suffixed with .cf-before-edit followed by an integer representing the nth previous version of the file. The number of rotations is managed by the rotate attribute in edit_defaults.

body edit_defaults backup( edit_backup )
{
  edit_backup => "$(edit_backup)";
  rotate => "2";
}

bundle agent main
{
  files:
    "/tmp/example_edit_backup_rotate"
      create => "true";

    "/tmp/example_edit_backup_rotate"
      edit_line => insert_lines("Hello World"),
      edit_defaults => backup("rotate");

    "/tmp/example_edit_backup_rotate"
      handle => "edit_2",
      edit_line => insert_lines("Goodbye"),
      edit_defaults => backup("rotate");

  vars:
    "example_files" slist => lsdir( "/tmp/", "example_edit_backup_rotate.*", false);

  reports:
    "$(example_files)";
}

Outputs:

R: example_edit_backup_rotate
R: example_edit_backup_rotate.cf-before-edit.1
R: example_edit_backup_rotate.cf-before-edit.2

See also: default_repository in body agent control, copy_backup in body copy_from, rotate in body edit_defaults

empty_file_before_editing

Description: Baseline memory model of file to zero/empty before commencing promised edits.

Emptying a file before reconstructing its contents according to a fixed recipe allows an ordered procedure to be convergent.

Type: boolean

Default value: false

Example:

     body edit_defaults example
     {
     empty_file_before_editing => "true";
     }

inherit

Description: If true this causes the sub-bundle to inherit the private classes of its parent

Type: boolean

Example:

     bundle agent name
     {
     methods:

       "group name" usebundle => my_method,
                      inherit => "true";
     }

     body edit_defaults example
     {
     inherit => "true";
     }

History: Was introduced in 3.4.0, Enterprise 3.0.0 (2012)

Default value: false

Notes: The inherit constraint can be added to the CFEngine code in two places: for edit_defaults and in methods promises. If set to true, it causes the child-bundle named in the promise to inherit only the classes of the parent bundle. Inheriting the variables is unnecessary as the child can always access the parent's variables by a qualified reference using its bundle name. For example, $(bundle.variable).

max_file_size

Description: Do not edit files bigger than this number of bytes

max_file_size is a local, per-file sanity check to make sure the file editing is sensible. If this is set to zero, the check is disabled and any size may be edited. The default value of max_file_size is determined by the global control body setting whose default value is 100k.

Type: int

Allowed input range: 0,99999999999

Example:

     body edit_defaults example
     {
     max_file_size => "50K";
     }

recognize_join

Description: Join together lines that end with a backslash, up to 4kB limit

If set to true, this option allows CFEngine to process line based files with backslash continuation. The default is to not process continuation backslashes.

Back slash lines will only be concatenated if the file requires editing, and will not be restored. Restoration of the backslashes is not possible in a meaningful and convergent fashion.

Type: boolean

Default value: false

Example:

     files:

       "/tmp/test_insert"
                 create => "true",
              edit_line => Insert("$(insert.v)"),
          edit_defaults => join;
     }

     #

     body edit_defaults join
     {
     recognize_join => "true";
     }

rotate

Description: How many backups to store if 'rotate' edit_backup strategy is selected. Defaults to 1

Used for log rotation. If the file is named foo and the rotate attribute is set to 4, as above, then initially foo is copied to foo.1 and the old file foo is zeroed out. In other words, the inode of the original logfile does not change, but the original logfile will be empty after the rotation is complete.

The next time the promise is executed, foo.1 will be renamed foo.2, foo is again copied to foo.1 and the old file foo is again zeroed out.

A promise may typically be executed as guarded by time-based or file-size-based classes. Each time the promise is executed the files are copied/zeroed or rotated (as above) until there are rotate numbered files, plus the one "main" file. In the example above, the file foo.3 will be renamed foo.4, but the old version of the file foo.4 will be deleted (that is, it "falls off the end" of the rotation).

Type: int

Allowed input range: 0,99

Example:

     body edit_defaults example
     {
     edit_backup => "rotate";
     rotate => "4";
     }

See also: edit_backup in body edit_defaults

edit_line

Type: bundle edit_line

edit_template

Description: Path to Mustache or native-CFEngine template file to expand

Type: string

Allowed input range: "?(/.*)

Example:

bundle agent example
{
   files:

     !use_mustache::

       "/etc/motd"
         create => "true",
         edit_template => "$(this.promise_dirname)/templates/motd.tpl",
         template_method => "cfengine";

     use_mustache::

       "/etc/motd"
         create => "true",
         edit_template => "$(this.promise_dirname)/templates/motd.mustache",
         template_method => "mustache";
}

History: Was introduced in 3.3.0, Nova 2.2.0 (2012). Mustache templates were introduced in 3.6.0.

See also: template_method, template_data, readjson(), parsejson(), readyaml(), parseyaml(), mergedata(), data, Customize Message of the Day

edit_template_string

Description: Mustache string to expand

Type: string

Allowed input range: (arbitrary string)

Example:

touch /tmp/example.txt printf "Welcome to host 'docs.cfengine.com'" > /tmp/example.txt ```

bundle agent example_using_template_method_inline_mustache
{
  vars:

      # Here we construct a data container that will be passed to the mustache
      # templating engine

      "d"
        data => '{ "host": "docs.cfengine.com" }';

      # Here we specify a string that will be used as an inline mustache template
      "mustache_template_string"
        string => "Welcome to host '{{{host}}}'";

  files:
      # Here we render the file using the data container and inline template specification

      "/tmp/example.txt"
        create => "true",
        template_method => "inline_mustache",
        edit_template_string => "$(mustache_template_string)",
        template_data => @(d);

  reports:
      "/tmp/example.txt"
        printfile => cat( $(this.promiser) );
}

body printfile cat(file)
{
        file_to_print => "$(file)";
        number_of_lines => "inf";
}
bundle agent __main__
{
      methods: "example_using_template_method_inline_mustache";
}

R: /tmp/example.txt
R: Welcome to host 'docs.cfengine.com'

This policy can be found in /var/cfengine/share/doc/examples/template_method-inline_mustache.cf and downloaded directly from github.

History: Was introduced in 3.12.0

See also: template_method, template_data, readjson(), parsejson(), readyaml(), parseyaml(), mergedata(), data, Customize Message of the Day

edit_xml

Type: bundle edit_xml

file_select

Type: body file_select

See also: Common Body Attributes

leaf_name

Description: List of regexes that match an acceptable name

This pattern matches only the node name of the file, not its path.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body file_select example
     {
     leaf_name => { "S[0-9]+[a-zA-Z]+", "K[0-9]+[a-zA-Z]+" };
     file_result => "leaf_name";
     }

path_name

Description: List of pathnames to match acceptable target

Path name and leaf name can be conveniently tested for separately by use of appropriate regular expressions.

Type: slist

Allowed input range: "?(/.*)

Example:

     body file_select example
     {
     leaf_name => { "prog.pid", "prog.log" };
     path_name => { "/etc/.*", "/var/run/.*" };

     file_result => "leaf_name.path_name"
     }

search_mode

Description: A list of mode masks for acceptable file permissions

The mode may be specified in symbolic or numerical form with + and - constraints. Concatenation ug+s implies u OR g, and u+s,g+s implies u AND g.

Type: slist

Allowed input range: [0-7augorwxst,+-]+

Example:

     bundle agent testbundle
     {
     files:

       "/home/mark/tmp/testcopy"

         file_select => by_modes,
         transformer => "/bin/echo DETECTED $(this.promiser)",
         depth_search => recurse("inf");

     }

     body file_select by_modes
     {
     search_mode => { "711" , "666" };
     file_result => "mode";
     }

     body depth_search recurse(d)
     {
     depth => "$(d)";
     }

search_size

Type: irange[int,int]

Allowed input range: 0,inf

Description: Integer range of file sizes in bytes

Example:

     body file_select example
     {
     search_size => irange("0","20k");
     file_result => "size";
     }

search_owners

Description: List of acceptable user names or ids for the file, or regexes to match

A list of anchored regular expressions any of which must match the entire userid.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body file_select example
     {
     search_owners => { "mark", "jeang", "student_.*" };
     file_result => "owner";
     }

Notes: Windows does not have user ids, only names.

search_groups

Description: List of acceptable group names or ids for the file, or regexes to match

A list of anchored regular expressions, any of which must match the entire group.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body file_select example
     {
     search_groups => { "users", "special_.*" };
     file_result => "group";
     }

Notes: On Windows, files do not have group associations.

search_bsdflags

Description: String of flags for bsd file system flags expected set

Extra BSD file system flags (these have no effect on non-BSD versions of CFEngine). See the manual page for chflags for more details.

Type: slist

Allowed input range: [+-]*[(arch|archived|nodump|opaque|sappnd|sappend|schg|schange|simmutable|sunlnk|sunlink|uappnd|uappend|uchg|uchange|uimmutable|uunlnk|uunlink)]+

Example:

     body file_select xyz
     {
     search_bsdflags => "archived|dump";
     file_result => "bsdflags";
     }

ctime

Description: Range of change times (ctime) for acceptable files

The file's change time refers to both modification of content and attributes, such as permissions. On Windows, ctime refers to creation time.

Type: irange[int,int]

Allowed input range: 0,2147483647

Example:

     body files_select example
     {
     ctime => irange(ago(1,0,0,0,0,0),now);
     file_result => "ctime";
     }

mtime

Description: Range of modification times (mtime) for acceptable files

The file's modification time refers to both modification of content but not other attributes, such as permissions.

Type: irange[int,int]

Allowed input range: 0,2147483647

Example:

     body files_select example
     {
     # Files modified more than one year ago (i.e., not in mtime range)
     mtime => irange(ago(1,0,0,0,0,0),now);
     file_result => "!mtime";
     }

atime

Description: Range of access times (atime) for acceptable files

A range of times during which a file was accessed can be specified in a file_select body.

Type: irange[int,int]

Allowed input range: 0,2147483647

Example:

     body file_select used_recently
     {
     # files accessed within the last hour
     atime     => irange(ago(0,0,0,1,0,0),now);
     file_result => "atime";
     }


     body file_select not_used_much
     {
     # files not accessed since 00:00 1st Jan 2000 (in the local timezime)
     atime     => irange(on(2000,1,1,0,0,0),now);
     file_result => "!atime";
     }

exec_regex

Description: Matches file if this regular expression matches any full line returned by the command

The regular expression must be used in conjunction with the exec_program test. In this way the program must both return exit status 0 and its output must match the regular expression. The entire output must be matched.

Type: string

Allowed input range: .*

Example:

     body file_select example
     {
     exec_regex => "SPECIAL_LINE: .*";
     exec_program => "/path/test_program $(this.promiser)";
     file_result => "exec_program.exec_regex";
     }

exec_program

Description: Execute this command on each file and match if the exit status is zero

This is part of the customizable file search criteria. If the user-defined program returns exit status 0, the file is considered matched.

Type: string

Allowed input range: "?(/.*)

Example:

     body file_select example
     {
     exec_program => "/path/test_program $(this.promiser)";
     file_result => "exec_program";
     }

file_types

Description: List of acceptable file types from menu choices

File types vary in details between operating systems. The main POSIX types are provided here as menu options, with reg being a synonym for plain. In both cases this means not one of the "special" file types.

Type: (option list)

Allowed input range:

    plain
    reg
    symlink
    dir
    socket
    fifo
    door
    char
    block

Example:

     body file_select filter
     {
     file_types => { "plain","symlink" };

     file_result => "file_types";
     }

issymlinkto

Description: List of regular expressions to match file objects

If the file is a symbolic link that points to files matched by one of these expressions, the file will be selected.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body file_select example
     {
     issymlinkto => { "/etc/[^/]*", "/etc/init\.d/[a-z0-9]*" };
     }

Notes: Windows does not support symbolic links, so this attribute is not applicable on that platform.

file_result

Description: Logical expression combining classes defined by file search criteria

The syntax is the same as for a class expression, since the file selection is a classification of the file-search in the same way that system classes are a classification of the abstract host-search. That is, you may specify a boolean expression involving any of the file-matching components.

Type: string

Allowed input range: [!*(leaf_name|path_name|file_types|mode|size|owner|group|atime|ctime|mtime|issymlinkto|exec_regex|exec_program|bsdflags)[|.]*]*

Example:

     body file_select year_or_less
     {
     mtime       => irange(ago(1,0,0,0,0,0),now);
     file_result => "mtime";
     }

     body file_select my_pdf_files_morethan1dayold
     {
     mtime         => irange(ago(0,0,1,0,0,0),now);
     leaf_name     => { ".*\.pdf" , ".*\.fdf" };
     search_owners => { "mark" };

     file_result => "owner.leaf_name.!mtime";
     }

You may specify arbitrarily complex file-matching parameters, such as what is shown above, "is owned by mark, has the extension '.pdf' or '.fdf', and whose modification time is not between 1 day ago and now"; that is, it is older than 1 day.

See also: process_result

file_type

Description: By default, regular files are created, when specifying create => "true". You can create fifos through this mechanism as well, by specifying fifo in file_type.

Type: string

Allowed input range:

    regular
    fifo

Type: (menu option)

Allowed input range:

• regular
• fifo

Default value: cfengine

link_from

Type: body link_from

See also: Common Body Attributes

copy_patterns

Description: A set of patterns that should be copied and synchronized instead of linked

During the linking of files, it is sometimes useful to buffer changes with an actual copy, especially if the link is to an ephemeral file system. This list of patterns matches files that arise during a linking policy. A positive match means that the file should be copied and updated by modification time.

Type: slist

Allowed input range: (arbitrary string)

Example:

     body link_from example
     {
     copy_patterns =>  { "special_node1", "/path/special_node2" };
     }

link_children

Description: true/false whether to link all directory's children to source originals

If the promiser is a directory, instead of copying the children, link them to the source.

Type: boolean

Default value: false

Example implementation:

body link_from linkchildren(tofile)
{
      source        => "$(tofile)";
      link_type     => "symlink";
      when_no_source  => "force";
      link_children => "true";
      when_linking_children => "if_no_such_file"; # "override_file";
}

body link_from linkfrom(source, type)
{
      source => $(source);
      link_type => $(type);
}

Example usage:

body file control
{
  inputs => { "$(sys.libdir)/stdlib.cf" };
}

bundle agent main
{
  files:

      # This will make symlinks to each file in /var/cfengine/bin
      # for example:
      # '/usr/local/bin/cf-agent' -> '/var/cfengine/bin/cf-agent'
      # '/usr/local/bin/cf-serverd' -> '/var/cfengine/bin/cf-serverd'
      "/usr/local/bin"
        link_from => linkchildren("/var/cfengine/bin"),
    comment => "We like for cfengine binaries to be available inside of the
                    common $PATH";
}

This policy can be found in /var/cfengine/share/doc/examples/symlink_children.cf and downloaded directly from github.

link_type

Description: The type of link used to alias the file

This determines what kind of link should be used to link files. Users are advised to be wary of 'hard links' (see Unix manual pages for the ln command). The behavior of non-symbolic links is often precarious and unpredictable.

Note that symlink is synonymous with absolute links, which are different from relative links. Although all of these are symbolic links, the nomenclature here is defined such that symlink and absolute are equivalent . When verifying a link, choosing 'relative' means that the link must be relative to the source, so relative and absolute links are mutually exclusive.

Type: (menu option)

Allowed input range:

    symlink
    hardlink
    relative
    absolute

Default value: symlink

Example impelementation:

body link_from ln_s(x)
{
      link_type => "symlink";
      source => "$(x)";
      when_no_source => "force";
}

     body link_from example
     {
     link_type => "symlink";
     source => "/tmp/source";
     }

Example usage:

body file control
{
  inputs => { "$(sys.libdir)/stdlib.cf" };  
}

bundle agent main
{
  files:

      # We use move_obstructions because we want the symlink to replace a
      # regular file if necessary.
      "/etc/apache2/sites-enabled/www.cfengine.com" -> { "webmaster@cfengine.com" }
        link_from => ln_s( "/etc/apache2/sites-available/www.cfengine.com" ),
        move_obstructions => "true",
        comment => "We always want our website to be enabled.";
}

This policy can be found in /var/cfengine/share/doc/examples/symlink.cf and downloaded directly from github.

Notes: On Windows, hard links are the only supported type.

source

Description: The source file to which the link should point

For remote copies this refers to the file name on the remote server.

Type: string

Allowed input range: .+

Example:

     body link_from example
     {
     source => "/path/to/source";
     }

when_linking_children

Description: Policy for overriding existing files when linking directories of children

The options refer to what happens if the directory already exists, and is already partially populated with files. If the directory being copied from contains a file with the same name as that of a link to be created, it must be decided whether to override the existing destination object with a link, or simply omit the automatic linkage for files that already exist. The latter case can be used to make a copy of one directory with certain fields overridden.

Type: (menu option)

Allowed input range:

    override_file
    if_no_such_file

Example:

     body link_from example
     {
     when_linking_children => "if_no_such_file";
     }

when_no_source

Description: Behavior when the source file to link to does not exist

This describes how CFEngine should respond to an attempt to create a link to a file that does not exist. The options are to force the creation to a file that does not (yet) exist, delete any existing link, or do nothing.

Type: (menu option)

Allowed input range:

    force
    delete
    nop

Default value: nop

Example:

     body link_from example
     {
     when_no_source => "force";
     }

move_obstructions

Description: true/false whether to move obstructions to file-object creation

If we have promised to make file X a link, but it already exists as a file, or vice-versa, or if a file is blocking the creation of a directory, then normally CFEngine will report an error. If this is set, existing objects will be moved aside to allow the system to heal without intervention. Files and directories are saved/renamed, but symbolic links are deleted.

Note that symbolic links for directories are treated as directories, not links. This behavior can be discussed, but the aim is to err on the side of caution.

Type: boolean

Default value: false

Example:

    files:

      "/tmp/testcopy"

        copy_from    => mycopy("/tmp/source"),
        move_obstructions => "true",
        depth_search => recurse("inf");

Notes: Some operating systems (Solaris) use symbolic links in path names. Copying to a directory could then result in renaming of the important link, if the behavior is different.

pathtype

Description: Menu option for interpreting promiser file object

By default, CFEngine makes an educated guess as to whether the promise pathname involves a regular expression or not. This guesswork is needed due to cross-platform differences in filename interpretation.

If CFEngine guesses (or is told) that the pathname uses a regular expression pattern, it will undertake a file search to find possible matches. This can consume significant resources, and so the guess option will always try to optimize this. Guesswork is, however, imperfect, so you have the option to declare your intention.

Type: (menu option)

Allowed input range:

    literal
    regex
    guess

If the keyword literal is invoked, a path will be treated as a literal string regardless of what characters it contains. If it is declared regex, it will be treated as a pattern to match.

Note that CFEngine splits the promiser up into path links before matching, so that each link in the path chain is matched separately. Thus it it meaningless to have a / in a regular expression, as the comparison will never see this character.

Default value: guess

Example:

files:

   "/var/lib\d"
      pathtype => "guess",  # best guess (default)
         perms => system;

   "/var/lib\d"
      pathtype => "regex",  # force regex interpretation
         perms => system;

   "/var/.*/lib"

      pathtype => "literal",    # force literal interpretation
         perms => system;

In these examples, at least one case implies an iteration over all files/directories matching the regular expression, while the last case means a single literal object with a name composed of dots and stars.

Notes: On Windows paths using regex must use the forward slash (/) as path separator, since the backward slash has a special meaning in a regular expression. Literal paths may also use backslash (\) as a path separator.

perms

Type: body perms

See also: Common Body Attributes

bsdflags

Description: List of menu options for BSD file system flags to set

Type: slist

Allowed input range: [+-]*[(arch|archived|nodump|opaque|sappnd|sappend|schg|schange|simmutable|sunlnk|sunlink|uappnd|uappend|uchg|uchange|uimmutable|uunlnk|uunlink)]+

Example:

     body perms example
     {
     bsdflags => { "uappnd","uchg","uunlnk","nodump",
                   "opaque","sappnd","schg","sunlnk" };
     }

Notes: The BSD Unices (FreeBSD, OpenBSD, NetBSD) and MacOSX have additional file system flags which can be set. Refer to the BSD chflags documentation for this.

groups

Description: List of acceptable groups of group ids, first is change target

The first named group in the list is the default that will be configured if the file does not match an element of the list. The reserved word none may be used to match files that are not owned by a registered group.

Type: slist

Allowed input range: [a-zA-Z0-9_$.-]+

Example:

     body perms example
     {
     groups => { "users", "administrators" };
     }

Notes: On Windows, files do not have file groups associated with them, and thus this attribute is ignored. ACLs may be used in place for this.

mode

Description: File permissions

The mode string may be symbolic or numerical, like chmod.

Type: string

Allowed input range: [0-7augorwxst,+-]+

Example:

     body perms example
     {
     mode => "a+rx,o+w";
     }

See also: rxdirs

Notes: This is ignored on Windows, as the permission model uses ACLs.

owners

Description: List of acceptable owners or user ids, first is change target

The first user is the reference value that CFEngine will set the file to if none of the list items matches the true state of the file. The reserved word none may be used to match files that are not owned by a registered user.

Type: slist

Allowed input range: [a-zA-Z0-9_$.-]+

Example:

     body perms example
     {
     owners => { "mark", "wwwrun", "jeang" };
     }

Notes: On Windows, users can only take ownership of files, never give it. Thus, the first user in the list should be the user running the CFEngine process (usually Administrator). Additionally, some groups may be owners on Windows (such as the Administrators group).

rxdirs

Description: true/false add execute flag for directories if read flag is set

Default behavior is to set the x flag on directories automatically if the r flag is specified in mode.

Type: boolean

Example:

     body perms rxdirs
     {
     rxdirs => "false";
     }

See also: mode

Notes: This is ignored on Windows, as the permission model uses ACLs.

rename

Type: body rename

See also: Common Body Attributes

disable

Description: true/false automatically rename and remove permissions

Disabling a file means making it unusable. For executables this means preventing execution, for an information file it means making the file unreadable.

Type: boolean

Default value: false

Example:

     body rename example
     {
     disable => "true";
     disable_suffix => ".nuked";
     }

disable_mode

Description: The permissions to set when a file is disabled

To disable an executable it is not enough to rename it, you should also remove the executable flag.

Type: string

Allowed input range: [0-7augorwxst,+-]+

Example:

     body rename example
     {
     disable_mode => "0600";
     }

disable_suffix

Description: The suffix to add to files when disabling

To disable files in a particular manner, use this string suffix.

Type: string

Allowed input range: (arbitrary string)

Default value: .cfdisabled

Example:

     body rename example
     {
     disable => "true";
     disable_suffix => ".nuked";
     }

newname

Description: The desired name for the current file

Type: string

Allowed input range: (arbitrary string)

Example:

     body rename example(s)
     {
     newname => "$(s)";
     }

rotate

Description: Maximum number of file rotations to keep

Used for log rotation. If the file is named foo and the rotate attribute is set to 4, as above, then initially foo is copied to foo.1 and the old file foo is zeroed out (that is, the inode of the original logfile does not change, but the original log file will be empty after the rotation is complete).

The next time the promise is executed, foo.1 will be renamed foo.2, foo is again copied to foo.1 and the old file foo is again zeroed out.

Each time the promise is executed (and typically, the promise would be executed as guarded by time-based or file-size-based classes), the files are copied/zeroed or rotated as above until there are rotate numbered files plus the one "main" file.

Type: int

Allowed input range: 0,99

Example:

     body rename example
     {
     rotate => "4";
     }

In the example above, the file foo.3 will be renamed foo.4, but the old version of the file foo.4 will be deleted (that is, it "falls off the end" of the rotation).

repository

Description: Name of a repository for versioning

A local repository for this object, overrides the default.

Note that when a repository is specified, the files are stored using the canonified directory name of the original file, concatenated with the name of the file. So, for example, /usr/local/etc/postfix.conf would ordinarily be stored in an alternative repository as _usr_local_etc_postfix.conf.cfsaved.

Type: string

Allowed input range: "?(/.*)

Example:

    files:

     "/path/file"

       copy_from => source,
       repository => "/var/cfengine/repository";

template_data

Description: The data container to be passed to the template (Mustache or inline_mustache). It can come from a function call like mergedata() or from a data container reference like @(mycontainer).

Type: data

Allowed input range: (arbitrary string)

Example:

    files:

     "/path/file"
     ...
     edit_template => "mytemplate.mustache",
     template_data => parsejson('{"message":"hello"}'),
     template_method => "mustache";

Example:

    vars:
     "mycontainer" data => '[ 1, 2, 3 ]';

    files:

     "/path/file"
     ...
     edit_template => "mytemplate.mustache",
     template_data => @(mycontainer),
     template_method => "mustache";

If this attribute is omitted, the result of the datastate() function call is used instead. See edit_template for how you can use the data state in Mustache.

See also: edit_template, template_method, datastate()

template_method

Description: The template type.

By default cfengine requests the native CFEngine template implementation, but you can use mustache or inline_mustache as well.

Type: (menu option)

Allowed input range:

• cfengine
• inline_mustache
• mustache

Default value: cfengine

template_method cfengine

The default native-CFEngine template format (selected when template_method is cfengine or unspecified) uses inline tags to mark regions and classes. Each line represents an insert_lines promise, unless the promises are grouped into a block using:

    [%CFEngine BEGIN %]
    ...
    [%CFEngine END %]

Variables, scalars and list variables are expanded within each promise based on the current scope of the calling promise. If lines are grouped into a block, the whole block is repeated when lists are expanded (see the Special Topics Guide on editing).

If a class-context modified is used:

[%CFEngine class-expression:: %]

then the lines that follow are only inserted if the context matches the agent's current context. This allows conditional insertion.

Note: Because classic templates are built on top of edit_line, identical lines will not be rendered more than once unless they are included within a block. This includes blank lines.

Example contrived cfengine template:

    #This is a template file /templates/input.tmpl

    These lines apply to anyone

    [%CFEngine solaris.Monday:: %]
    Everything after here applies only to solaris on Mondays
    until overridden...

    [%CFEngine linux:: %]
    Everything after here now applies now to linux only.

    [%CFEngine BEGIN %]
    This is a block of text
    That contains list variables: $(some.list)
    With text before and after.
    [%CFEngine END %]

    nameserver $(some.list)

Example cfengine template for apache vhost directives:

    [%CFEngine any:: %]
    VirtualHost $(sys.ipv4[eth0]):80>
            ServerAdmin             $(stage_file.params[apache_mail_address][1])
            DocumentRoot            /var/www/htdocs
            ServerName              $(stage_file.params[apache_server_name][1])
            AddHandler              cgi-script cgi
            ErrorLog                /var/log/httpd/error.log
            AddType                 application/x-x509-ca-cert .crt
            AddType                 application/x-pkcs7-crl    .crl
            SSLEngine               off
            CustomLog               /var/log/httpd/access.log
    /VirtualHost>

    [%CFEngine webservers_prod:: %]
    [%CFEngine BEGIN %]
    VirtualHost $(sys.ipv4[$(bundle.interfaces)]):443>
            ServerAdmin             $(stage_file.params[apache_mail_address][1])
            DocumentRoot            /var/www/htdocs
            ServerName              $(stage_file.params[apache_server_name][1])
            AddHandler              cgi-script cgi
            ErrorLog                /var/log/httpd/error.log
            AddType                 application/x-x509-ca-cert .crt
            AddType                 application/x-pkcs7-crl    .crl
            SSLEngine               on
            SSLCertificateFile      $(stage_file.params[apache_ssl_crt][1])
            SSLCertificateKeyFile   $(stage_file.params[apache_ssl_key][1])
            CustomLog               /var/log/httpd/access.log
    /VirtualHost>
    [%CFEngine END %]

template_method inline_mustache

When template_method is inline_mustache the mustache input is not a file but a string and you must set edit_template_string. The same rules apply for inline_mustache and mustache. For mustache explanation see template_method mustache

Example:

touch /tmp/example.txt printf "Welcome to host 'docs.cfengine.com'" > /tmp/example.txt ```

bundle agent example_using_template_method_inline_mustache
{
  vars:

      # Here we construct a data container that will be passed to the mustache
      # templating engine

      "d"
        data => '{ "host": "docs.cfengine.com" }';

      # Here we specify a string that will be used as an inline mustache template
      "mustache_template_string"
        string => "Welcome to host '{{{host}}}'";

  files:
      # Here we render the file using the data container and inline template specification

      "/tmp/example.txt"
        create => "true",
        template_method => "inline_mustache",
        edit_template_string => "$(mustache_template_string)",
        template_data => @(d);

  reports:
      "/tmp/example.txt"
        printfile => cat( $(this.promiser) );
}

body printfile cat(file)
{
        file_to_print => "$(file)";
        number_of_lines => "inf";
}
bundle agent __main__
{
      methods: "example_using_template_method_inline_mustache";
}

R: /tmp/example.txt
R: Welcome to host 'docs.cfengine.com'

This policy can be found in /var/cfengine/share/doc/examples/template_method-inline_mustache.cf and downloaded directly from github.

History: Was introduced in 3.12.0

See also: edit_template_string, template_data, datastate()

template_method mustache

When template_method is mustache data must be provided to render the template with. Data can be provided by functions that return data ( i.e. mergedata(), mapdata(), readdata(), findprocesses(), etc ...), lists or data variables by reference @(data), or by specifying data as inline json (which can take advantage of data wrapping). For convenience if template_data is not specified the output of datastate() will be used. Thus the datastate() (all variables and classes defined) is the default.

From mustache Variables, Sections, Inverted Sections, Comments, and the Set Delimiter TAG TYPES are implemented.

NOTE: Partials and Lambdas are not currently supported.

template_method mustache Variables

The most basic tag type is the variable. A {{name}} tag in a basic template will try to find the name key in the current context. If there is no name key, the parent contexts will be checked recursively. If the top context is reached and the name key is still not found, nothing will be rendered.

All variables are HTML escaped by default. If you want to return unescaped HTML, use the triple mustache: {{{name}}} or an ampersand ({{& name}}).

A variable "miss" returns an empty string.

bundle agent main
{
  vars:
    "data" data => '{ "key": "Hello World & 3>2!" }';

  reports:
    "$(with)"
      with => string_mustache(
"{{key}}
{{{key}}}
{{&key}}
Missing '{{missing}}' varibles render empty strings.",
                              data);
}

R: Hello World & 3>2!
Hello World & 3>2!
Hello World & 3>2!
Missing '' varibles render empty strings.

This policy can be found in /var/cfengine/share/doc/examples/mustache_variables.cf and downloaded directly from github.

template_method mustache Sections

Sections render blocks of text one or more times, depending on the value of the key in the current context.

A section begins with a pound and ends with a slash. That is, {{#key}} begins a "person" section while {{/key}} ends it.

The behavior of the section is determined by the value of the key.

Empty lists:

If the key exists and has a value of false or an empty list, the HTML between the pound and slash will not be displayed.

bundle agent main
{
  vars:
    "data" data => '{ "list": [ ] }';

  reports:
    "The list contains $(with)."
      with => string_mustache("{{#list}} {{{.}}}{{/list}}",
                              data);
}

R: The list contains .

This policy can be found in /var/cfengine/share/doc/examples/mustache_sections_empty_list.cf and downloaded directly from github.

Non-Empty Lists:

bundle agent main
{
  vars:
    "data" data => '{ "list": [ "1", "2", "3" ] }';

  reports:
    "$(with)"
      with => string_mustache("{{#list}} {{{.}}}{{/list}}",
                              data);
}

R:  1 2 3

This policy can be found in /var/cfengine/share/doc/examples/mustache_sections_non_empty_list.cf and downloaded directly from github.

Non-False Values:

When the value is non-false but not a list, it will be used as the context for a single rendering of the block.

bundle agent main
{
  vars:
      "data" data => parsejson('{ "classes": { "example": true } }');

  reports:
      "$(with)"
        with => string_mustache("{{#classes.example}}This is an example.{{/classes.example}}",
                                data);
}

R: This is an example.

This policy can be found in /var/cfengine/share/doc/examples/mustache_sections_non_false_value.cf and downloaded directly from github.

template_method mustache Inverted Sections

An inverted section begins with a caret (hat) and ends with a slash. That is {{^key}} begins a "key" inverted section while {{/key}} ends it.

While sections can be used to render text one or more times based on the value of the key, inverted sections may render text once based on the inverse value of the key. That is, they will be rendered if the key doesn't exist, is false, or is an empty list.

bundle agent main
{
  reports:
    "CFEngine $(with)"
      with => string_mustache("{{^classes.enterprise_edition}}Community{{/classes.enterprise_edition}}{{#classes.enterprise_edition}}Enterprise{{/classes.example}}",
                              datastate());
}

R: CFEngine Community

This policy can be found in /var/cfengine/share/doc/examples/mustache_sections_inverted.cf and downloaded directly from github.

template_method mustache Comments

Comments begin with a bang and are ignored. Comments may contain newlines.

bundle agent main
{
  reports:
    "$(with)"
      with => string_mustache("Render this.{{! But not
this}}",
                              datastate());
}

R: Render this.

This policy can be found in /var/cfengine/share/doc/examples/mustache_comments.cf and downloaded directly from github.

template_method mustache Set Delimiter

Set Delimiter tags start with an equal sign and change the tag delimiters from {{ and }} to custom strings.

bundle agent main
{
  vars:
    "data" data => '{ "key": "value of key in data" }';

  reports:
      "$(with)"
        with => string_mustache("{{=<% %>=}}key has <% key %>",
                                data);
}

R: key has value of key in data

This policy can be found in /var/cfengine/share/doc/examples/mustache_set_delimiters.cf and downloaded directly from github.

template_method mustache extensions

The following are CFEngine-specific extensions.

-top- special key representing the complete data given. Useful for iterating over the top level of a container {{#-top-}} ... {{/-top-}} and rendering json representation of data given with $ and %.

bundle agent main
{
  vars:
      "data" data => '{ "key": "value", "list": [ "1", "2" ] }';

  reports:
      "-top- contains$(const.n)$(with)"
        with => string_mustache("{{%-top-}}", data );
}

R: -top- contains
{
  "key": "value",
  "list": [
    "1",
    "2"
  ]
}

This policy can be found in /var/cfengine/share/doc/examples/mustache_extension_top.cf and downloaded directly from github.

% variable prefix causing data to be rendered as multi-line json representation. Like output from storejson().

bundle agent main
{
  reports:
      "$(with)"
        with => string_mustache( "{{%mykey}}",
                                 '{ "mykey": { "msg": "Hello World" } }' );
}

R: {
  "msg": "Hello World"
}

This policy can be found in /var/cfengine/share/doc/examples/mustache_extension_multiline_json.cf and downloaded directly from github.

$ variable prefix causing data to be rendered as compact json representation. Like output from format() with the %S format string.

bundle agent main
{
  vars:
      "msg" string => "Hello World";

      "report"
        string => string_mustache("{{$-top-}}", bundlestate( $(this.bundle) )  ),
        unless => isvariable( $(this.promiser) ); # Careful to not include
                                                  # ourselves so we only grab the
                                                  # state of the first pass.

  reports:
      "$(report)";
}

R: {"msg":"Hello World"}

This policy can be found in /var/cfengine/share/doc/examples/mustache_extension_compact_json.cf and downloaded directly from github.

@ expands the current key being iterated to complement the value as accessed with ..

bundle agent main
{
  reports:
      "$(with)"
        with => string_mustache("datastate() provides {{#-top-}} {{{@}}}{{/-top-}}", datastate() );
}

R: datastate() provides  classes vars

This policy can be found in /var/cfengine/share/doc/examples/mustache_extension_expand_key.cf and downloaded directly from github.

See also: edit_template, template_data, datastate()

touch

Description: true/false whether to touch time stamps on file

Type: boolean

Example:

    files:

     "/path/file"

       touch => "true";

transformer

Description: Command (with full path) used to transform current file (no shell wrapper used)

A command to execute, usually for the promised file to transform it to something else (but possibly to create the promised file based on a different origin file).

The promiser file must exist in order to effect the transformer.

Note also that if you use the $(this.promiser) variable or other variable in this command, and the file object contains spaces, then you should quote the variable. For example:

    transformer => "/usr/bin/gzip \"$(this.promiser)\"",

Note also that the transformer does not actually need to change the file. You can, for example, simply report on the existence of files with:

    transformer => "/bin/echo I found a file named $(this.promiser)",

The file streams stdout and stderr are redirected by CFEngine, and will not appear in any output unless you run cf-agent with the -v switch.

It is possible to set classes based on the return code of a transformer-command in a very flexible way. See the kept_returncodes, repaired_returncodes and failed_returncodes attributes.

Finally, you should note that the command is not run in a shell. This means that you cannot perform file redirection or create pipelines.

Type: string

Allowed input range: "?(/.*)

Example:

These examples show both types of promises.

    files:
      "/home/mark/tmp/testcopy"

        file_select => pdf_files,
        transformer => "/usr/bin/gzip $(this.promiser)",
        depth_search => recurse("inf");

In the first example, the promise is made on the file that we wish to transform. If the promised file exists, the transformer will change the file to a compressed version (and the next time CFEngine runs, the promised file will no longer exist, because it now has the .gz extension).

     classes:
        "do_update" expression => isnewerthan("/etc/postfix/alias",
                                              "/etc/postfix/alias.cdb");

     files:
        "/etc/postfix/alias.cdb"
           create => "true",        # Must have this!
           transformer => "/usr/sbin/postalias /etc/postfix/alias",
           ifvarclass => "do_update";

In the second example, the promise is made on the file resulting from the transformation (and the promise is conditional on the original file being newer than the result file). In this case, we must specify create = true. If we do not, then if the promised file is removed the transformer will not be executed.