Components and Common Control
While promises to configure your system are entirely user-defined, the
details of the operational behavior of the CFEngine software is of
course hard-coded. You can still configure the details of this
behavior using the control promise bodies. Control behavior is
defined in bodies because the actual promises are fixed and you only
change their details within sensible limits.
See the introduction for a high-level overview of the CFEngine components, and each component's reference documentation for the details about the specific control bodies.
Common Control
The common control body refers to those promises that are
hard-coded into all the components of CFEngine, and therefore
affect the behavior of all the components.
body common control
{
inputs => {
"update.cf",
"library.cf"
};
bundlesequence => {
update("policy_host.domain.tld"),
"main",
"cfengine2"
};
goal_categories => { "goals", "targets", "milestones" };
goal_patterns => { "goal_.*", "target.*" };
output_prefix => "cfengine>";
version => "1.2.3";
}
bundlesequence
Description: The bundlesequence contains promise bundles
to verify, in a specific order.
The bundlesequence determines which of the compiled bundles will be executed
by cf-agent and in what order they will be executed. The list refers to the
names of bundles (which might be parameterized, function-like objects).
The default value for bundlesequence is { "main" }.
A bundlesequence may also be specified using the -b or
--bundlesequence command line option.
Type: slist
Allowed input range: .*
Example:
body common control
{
bundlesequence => {
update("policy_host.domain.tld"),
"main",
"cfengine2"
};
}
Note: Only common and agent bundles are allowed to be listed in the
bundlesequence.
The order in which you execute bundles can affect the outcome of your promises. In general you should always define variables before you use them.
The bundlesequence is like a genetic makeup of a machine. The
bundles act like characteristics of the systems. If you want
different systems to have different bundlesequences, distinguish
them with classes
webservers::
bundlesequence => { "main", "web" };
others::
bundlesequence => { "main", "otherstuff" };
If you want to add a basic common sequence to all sequences, then use global variable lists to do this:
body common control
{
webservers::
bundlesequence => { @(g.bs), "web" };
others::
bundlesequence => { @(g.bs), "otherstuff" };
}
bundle common g
{
vars:
"bs" slist => { "main", "basic_stuff" };
}
History: The default to { "main" } was introduced in version 3.7.0, so if
you expect your policies to be run by older version, you'll need an explicit
bundlesequence.
bwlimit
Description: Coarse control of bandwidth any cf-serverd or cf-agent process will send out. In Bytes/sec.
Bandwidth limit is meant to set an upper bound of traffic coming out of CFEngine agents or servers, as a countermeasure against network abuse from them. The limit is applied to all interfaces (in total), a single process at a time. It can prevent network being flooded by CFEngine traffic when large files or many agents hit a single cf-serverd.
For more fine-grained control, please use operating system (eg. iptables) facilities.
Note: Bandwidth limiting is currently not supported on Windows.
Type: [float][float]
Default value: none (no limit)
Example:
body common control
{
bwlimit => "10M";
}
In this example, bwlimit is set to 10MBytes/sec = 80Mbit/s meaning that CFEngine would only consume up to ~80% of any 100Mbit ethernet interface.
cache_system_functions
Description: Controls the caching of the results of system
functions, e.g. execresult() and returnszero() for shell execution and
ldapvalue() and friends for LDAP queries. Without this setting,
CFEngine's evaluation model will evaluate functions multiple times,
which is a performance concern. See Functions.
Although you can override this to false, in practice you should
almost never need to do so. The effect of having it true (the
default) is that the expensive functions will be run just once and
then their result will be cached.
Note that caching is per-process so results will not be cached between
runs of e.g. cf-agent and cf-promises.
Type: boolean
Default value: true
Example:
cache_system_functions => "true";
History: Was introduced in version 3.6.0.
domain
Description: The domain string specifies the domain name for this host.
There is no standard, universal or reliable way of determining the DNS domain name of a host, so it can be set explicitly to simplify discovery and name-lookup.
Type: string
Allowed input range: .*
Example:
body common control
{
domain => "example.org";
}
goal_patterns
Description: Contains regular expressions that match promisees/topics considered to be organizational goals
It is used as identifier to mark business and organizational goals in CFEngine Enterprise. CFEngine uses this to match promisees that represent business goals in promises.
Type: slist
Allowed input range: (arbitrary string)
Example:
body common control
{
goal_patterns => { "goal_.*", "target.*" };
}
History: Was introduced in version 3.1.5, Nova 2.1.0 (2011)
ignore_missing_bundles
Description: Determines whether to ignore missing bundles.
If ignore_missing_bundles is set to true, if any bundles in the bundle
sequence do not exist, ignore and continue.
Type: boolean
Default value: false
Example:
ignore_missing_bundles => "true";
Notes:
This authorizes the bundlesequence to contain possibly "nonexistent" pluggable modules. It defaults to false, whereupon undefined bundles cause a fatal error in parsing, and a transition to failsafe mode.
ignore_missing_inputs
Description: If any input files do not exist, ignore and continue
The inputs lists determines which files are parsed by CFEngine. Normally stringent security checks are made on input files to prevent abuse of the system by unauthorized users.
Sometimes however, it is appropriate to consider the automatic plug-in of modules that might or might not exist. This option permits CFEngine to list possible files that might not exist and continue 'best effort' with those that do exist. The default of all Booleans is false, so the normal behavior is to signal an error if an input is not found.
Type: boolean
Default value: false
Example:
ignore_missing_inputs => "true";
inputs
Description: The inputs slist contains additional filenames to parse for promises.
The filenames specified are all assumed to be in the same directory
as the file which references them (this is usually
$(sys.workdir)/inputs, but may be overridden by the -f or
--file command line option.
Type: slist
Allowed input range: .*
Example:
body common control
{
inputs => {
"update.cf",
"library.cf"
};
}
See also: inputs in body file control
Notes:
If no filenames are specified, no other filenames will be included in the compilation process.
Library contents are checked for duplication by path and by hash. For
example, if you put library.cf twice in your inputs, the duplicate
library.cf is noticed because the same path is included twice. A
verbose-level message is emitted but otherwise there is no error.
In addition, if you include a file once with path /x/y/z.cf and
again with path /x/./y/z.cf, the duplicate file will be rejected
regardless of any path tricks or symbolic links. The contents are
hashed, so the same file can't be included twice.
lastseenexpireafter
Description: The value of lastseenexpireafter is the number of minutes
after which last-seen entries are purged. It is an enterprise-only feature.
Type: int
Allowed input range: 0,99999999999
Default value: One week
Example:
body common control
{
lastseenexpireafter => "72";
}
output_prefix
Description: The string prefix for standard output
Type: string
Allowed input range: (arbitrary string)
Example:
body common control
{
output_prefix => "my_cf3";
}
Notes:
On native Windows versions of CFEngine (Enterprise), this string is also prefixed messages in the event log.
package_inventory
Description: List of package module bodies to query for package lists.
Defines the list of package module bodies which will be queries for
package lists, for use in packagematching(), packageupdatesmatching() and in
Enterprise inventory reporting.
Type: slist
Allowed input range: (body names)
Example:
body common control
{
package_inventory => { "apt_get" };
}
package_module
Description: The default package module body to use.
Defines the default package module body to use for package promises, if none is specified in the promise.
Type: string
Allowed input range: (body name)
Example:
body common control
{
package_module => "apt_get";
}
protocol_version
Description: Defines the protocol to use for all outgoing connections.
Type: (menu option)
Allowed input range:
0undefined1classic2latest
Default value: 2
- 0 -
- undefined -
- 1 - Classic protocol
- classic - Alias to protocol 1
- 2 - TLS
- latest - Alias to protocol 2
Note: protocol_version can be specified at the individual promise level
using the body copy_from protocol_version
attribute.
See also: body copy_from protocol_version, allowlegacyconnects, allowtlsversion, allowciphers, tls_min_version, tls_ciphers, encrypt, logencryptedtransfers, ifencrypted
History: Introduced in CFEngine 3.6.0
require_comments
Description: The require_comments menu option policy warns about
promises that do not have comment documentation.
When true, cf-promises will report loudly on promises that do not have
comments. Variables promises are exempted from this rule, since
they may be considered self-documenting. This may be used as a policy Quality
Assurance measure, to remind policy makers to properly document their
promises.
Type: boolean
Default value: false
Example:
body common control
{
common::
require_comments => "true";
}
site_classes
Description: A site_classes contains classes that will represent
geographical site locations for hosts. These should be defined elsewhere in
the configuration in a classes promise.
This list is used to match against topics when connecting
inferences about host locations in the knowledge map. Normally any
CFEngine classes promise whose name is defined as a thing or topic
under class locations:: will be assumed to be a location defining
classifier. This list will add alternative class contexts for
interpreting location.
Type: slist
Allowed input range: [a-zA-Z0-9_!&@@$|.()\[\]{}:]+
Each string is expected to be a class.
Example:
body common control
{
site_classes => { "datacenters","datacentres" }; # locations is by default
}
History: Was introduced in version 3.2.0, Nova 2.1.0 (2011)
syslog_host
Description: The syslog_host contains the name or address of a
host to which syslog messages should be sent directly by UDP.
This is the hostname or IP address of a local syslog service to which all CFEngine's components may promise to send data.
Type: string
Allowed input range: [a-zA-Z0-9_$(){}.:-]+
Default value: localhost
Example:
body common control
{
syslog_host => "syslog.example.org";
syslog_port => "514";
}
syslog_port
Description: The value of syslog_port represents the port number
of a UDP syslog service.
It is the UDP port of a local syslog service to which all CFEngine's components may promise to send data.
Type: int
Allowed input range: 0,99999999999
Default value: 514
Example:
body common control
{
syslog_host => "syslog.example.org";
syslog_port => "514";
}
tls_ciphers
Description: List of ciphers allowed when making outgoing connections.
For a list of possible ciphers, see man page for "openssl ciphers".
Type: string
Allowed input range: (arbitrary string)
Default value: undefined
Example:
body common control
{
# Use one of these ciphers when making outbound connections
tls_ciphers => "AES128-SHA";
}
See also: protocol_version, allowciphers, tls_min_version, allowtlsversion, encrypt, logencryptedtransfers, ifencrypted
History: Introduced in CFEngine 3.7.0
tls_min_version
Description: Minimum tls version to allow for outgoing connections.
Type: string
Allowed input range: (arbitrary string)
Default value: 1.0
body common control
{
# Allow only TLSv1.1 or higher for outgoing connections
tls_min_version => "1.1";
}
See also: protocol_version, allowciphers, tls_ciphers, allowtlsversion, encrypt, ifencrypted, logencryptedtransfers
History: Introduced in CFEngine 3.7.0
version
Description: The version string contains the scalar version of the
configuration.
It is is used in error messages and reports.
Type: string
Allowed input range: (arbitrary string)
This string should not contain the colon ':' character, as this has a special meaning in the context of knowledge management. This restriction might be lifted later.
Example:
body common control
{
version => "1.2.3";
}
Deprecated attributes in body common control
The following attributes were functional in previous versions of CFEngine, but today they are deprecated, either because their functionality is being handled trasparently or because it doesn't apply to current CFEngine version.
- fips_mode
- host_licenses_paid