cf-runagent connects to a list of running instances of cf-serverd. It allows foregoing the usual cf-execd schedule to activate cf-agent. A user may send classes to be defined on the remote host. Two kinds of classes may be sent: classes to decide on which hosts cf-agent will be started, and classes that the user requests cf-agent should define on execution. The latter type is regulated by cf-serverd's role based access control. Additionally a user may send a list of bundles to activate on the remote host with the --remote-bundles argument. This argument takes one or more comma separated bundle names. Each of the bundles requested must be given explicit permission with an access promise matching the bundle names.

Notes:

  • cf-runagent always considers the class runagent to be defined.

Command reference

code
  --help        , -h       - Print the help message
  --background  , -b value - Parallelize connections (50 by default)
  --debug       , -d       - Enable debugging output
  --verbose     , -v       - Output verbose information about the behaviour of cf-runagent
  --log-level   , -g value - Specify how detailed logs should be. Possible values: 'error', 'warning', 'notice', 'info', 'verbose', 'debug'
  --dry-run     , -n       - All talk and no action mode - make no changes, only inform of promises not kept
  --version     , -V       - Output the version of the software
  --file        , -f value - Specify an alternative input file than the default. This option is overridden by FILE if supplied as argument.
  --define-class, -D value - Define a list of comma separated classes to be sent to a remote agent
  --select-class, -s value - Define a list of comma separated classes to be used to select remote agents by constraint
  --inform      , -I       - Print basic information about changes made to the system, i.e. promises repaired
  --remote-options, -o value - (deprecated)
  --diagnostic  , -x       - (deprecated)
  --hail        , -H value - Hail the following comma-separated lists of hosts, overriding default list
  --interactive , -i       - Enable interactive mode for key trust
  --timeout     , -t value - Connection timeout, seconds
  --color       , -C value - Enable colorized output. Possible values: 'always', 'auto', 'never'. If option is used, the default value is 'auto'
  --timestamp   , -l       - Log timestamps on each line of log output
  --ignore-preferred-augments           - Ignore def_preferred.json file in favor of def.json
  --log-modules  value - Enable even more detailed debug logging for specific areas of the implementation. Use together with '-d'. Use --log-modules=help for a list of available modules
  --remote-bundles value - Bundles to execute on the remote agent

See also: bundle resource_type in server access promises, cfruncommand in body server control

Control promises

Settings describing the details of the fixed behavioral promises made by cf-runagent. The most important parameter here is the list of hosts that the agent will poll for connections. This is easily read in from a file list, however when doing so always have a stable input source that does not depend on the network (including a database or directory service) in any way: introducing such dependencies makes configuration brittle.

code
body runagent control
{
    # default port is 5308
    hosts => { "127.0.0.1:5308", "eternity.iu.hio.no:80", "slogans.iu.hio.no" };

    #output_to_file => "true";
}

hosts

Description: List of host or IP addresses to attempt connection with

The complete list of contactable hosts. The values may be either numerical IP addresses or DNS names, optionally suffixed by a ':' and a port number. If no port number is given, the default CFEngine port 5308 is assumed.

Type: slist

Allowed input range: (arbitrary string)

Example:

code
body runagent control
{
  network1::
    hosts => { "host1.example.org", "host2", "host3" };

  network2::
    hosts => { "host1.example.com", "host2", "host3" };
}

port

Description: Default port for CFEngine server

Type: int

Allowed input range: 1,65535

Default value: 5308

Example:

code
body hub control
{
  port => "5308";
}

body server control
{
  specialhost::
   port => "5308";

  !specialhost::
   port => "5308";
}

Notes:

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.

Changing the standard port number is not recommended practice. You should not do it without a good reason.

force_ipv4

Description: true/false force use of ipv4 in connection

Type: boolean

Default value: false

Example:

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

Notes: IPv6 should be harmless to most users unless you have a partially or misconfigured setup.

trustkey

Description: true/false automatically accept all keys on trust from servers

If the server's public key has not already been trusted, this allows us to accept the key in automated key-exchange.

Note that, as a simple security precaution, trustkey should normally be set to 'false', to avoid key exchange with a server one is not one hundred percent sure about, though the risks for a client are rather low. 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:

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

encrypt

Description: true/false encrypt connections with servers

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:

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

background_children

Description: true/false parallelize connections to servers

Causes cf-runagent to attempt parallelized connections to the servers.

Type: boolean

Default value: false

Example:

code
body runagent control
{
  background_children => "true";
}

max_children

Description: Maximum number of simultaneous connections to attempt

For the run-agent this represents the maximum number of forked background processes allowed when parallelizing connections to servers. For the agent it represents the number of background jobs allowed concurrently. Background jobs often lead to contention of the disk resources slowing down tasks considerably; there is thus a law of diminishing returns.

Type: int

Allowed input range: 0,99999999999

Default value: 50 runagents

Example:

code
body runagent control
{
  max_children => "10";
}

output_to_file

Description: true/false whether to send collected output to file(s)

Filenames are chosen automatically and placed in the WORKDIR/outputs/hostname_runagent.out.

Type: boolean

Default value: false

Example:

code
body runagent control
{
  output_to_file => "true";
}

output_directory

Description: Directory where the output is stored

Defines the location for parallelized output to be saved when running cf-runagent in parallel mode.

Type: string

Allowed input range: "?(/.*)

Example:

code
body runagent control
{
  output_directory => "/tmp/run_output";
}

History: Was introduced in version 3.2.0, Enterprise 2.1.0 (2011)

timeout

Description: Connection timeout in seconds

Type: int

Allowed input range: 1,9999

Examples:

code
body runagent control
{
  timeout => "10";
}

See also: body copy_from timeout, agent default_timeout

Sockets

cf-runagent can be triggered by writing a hostname or IP into a socket provided by cf-execd.

Notes:

  • Unlike execution triggered with the cf-runagent binary, there is currently no capability to define additional options like defining additional classes, or the remote bundlesequence.

Example:

code
echo 'host001' > /var/cfengine/state/cf-execd.sockets/cf-runagent.socket

See also: cf-execd, runagent_socket_allow_users

History:

  • 3.18.0 Added socket for triggering cf-runagent by hostname or IP.