cf-execd
cf-execd is the scheduling daemon for cf-agent. It runs
cf-agent locally according to a schedule specified in policy code (executor
control body). After a cf-agent run is completed, cf-execd gathers output
from cf-agent, and may be configured to email the output to a specified
address. It may also be configured to splay (randomize)
the execution schedule to prevent synchronized cf-agent runs across a
network.
cf-execd keeps the promises made in common bundles, and is affected by
common and executor control bodies.
Command reference
--help , -h - Print the help message
--debug , -d - Enable debugging output
--verbose , -v - Output verbose information about the behaviour of the agent
--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
--define , -D value - Define a list of comma separated classes to be defined at the start of execution
--negate , -N value - Define a list of comma separated classes to be undefined at the start of execution
--no-lock , -K - Ignore locking constraints during execution (ifelapsed/expireafter) if "too soon" to run
--inform , -I - Print basic information about changes made to the system, i.e. promises repaired
--diagnostic , -x - Activate internal diagnostics (developers only)
--no-fork , -F - Run as a foreground processes (do not fork)
--once , -O - Run once and then exit (implies no-fork)
--no-winsrv , -W - Do not run as a service on windows - use this when running from a command shell (CFEngine Nova only)
--ld-library-path, -L value - Set the internal value of LD_LIBRARY_PATH for child processes
--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
Control Promises
These body settings determine the behavior of cf-execd,including scheduling
times and output capture to WORKDIR/outputs and relay via email.
body executor control
{
splaytime => "5";
mailto => "cfengine@example.org";
mailfrom => "cfengine@$(host).example.org";
smtpserver => "localhost";
schedule => { "Min00_05", "Min30_35" }
}
agent_expireafter
Description: Maximum agent runtime (in minutes)
Sets a maximum time on any run of the command in exec_command. If
no data is received from the pipe opened to the process created
with exec_command after the time has elapsed, the process gets
killed.
Note that if you have long-running jobs, they may get killed with
this setting. Therefore, you should ensure it is higher than any
run of cf-agent that you want to leave alone. Alternatively, you
can make your jobs output something to STDOUT at least as often as
this threshold. This will reset the timer.
Type: int
Allowed input range: 0,10080
Default value: 120
Example:
body executor control
{
agent_expireafter => "120";
}
Notes:
The setting will effectively allow you to set a threshold on the
number of simultaneous agents that are running. For example, if you
set it to 120 and you are using a 5-minute agent schedule, a
maximum of 120 / 5 = 24 agents should be enforced.
See Also: body action expireafter, body contain exec_timeout, body agent control expireafter
executorfacility
Description: Menu option for syslog facility level
Type: (menu option)
Allowed input range:
LOG_USER
LOG_DAEMON
LOG_LOCAL0
LOG_LOCAL1
LOG_LOCAL2
LOG_LOCAL3
LOG_LOCAL4
LOG_LOCAL5
LOG_LOCAL6
LOG_LOCAL7
See the syslog manual pages.
Default value: LOG_USER
Example:
body executor control
{
executorfacility => "LOG_USER";
}
exec_command
Description: The full path and command to the executable run by
default (overriding builtin)
The command is run in a shell encapsulation so pipes and shell symbols may be used if desired.
Type: string
Allowed input range: "?(/.*)
Example:
exec_command => "$(sys.workdir)/bin/cf-agent -f failsafe.cf && $(sys.workdir)/bin/cf-agent";
mailfrom
Description: Email-address cfengine mail appears to come from
Type: string
Allowed input range: .*@.*
Example:
body executor control
{
mailfrom => "mrcfengine@example.org";
}
mailmaxlines
Description: Maximum number of lines of output to send by email
This limit prevents anomalously large outputs from clogging up a system
administrator's mailbox. The output is truncated in the email report, but the
complete original transcript is stored in WORKDIR/outputs/* where it can be
viewed on demand. A reference to the appropriate file is given.
Type: int
Allowed input range: 0,1000
Default value: 30
Example:
body executor control
{
mailmaxlines => "100";
}
mailsubject
Description: The subject in the mail sent by CFEngine.
The subject can contain system variables, like for example IP address or architecture.
Type: string
Allowed input range: .*
Example:
body executor control
{
mailsubject => "CFEngine report ($(sys.fqhost))";
}
mailto
Description: Email-address cfengine mail is sent to
The address to whom email is sent if an smtp host is configured.
Type: string
Allowed input range: .*@.*
Example:
body executor control
{
mailto => "cfengine_alias@example.org";
}
schedule
Description: The class schedule used by cf-execd for activating cf-agent
The list should contain class expressions comprised of classes
which are visible to the cf-execd daemon. In principle, any
defined class expression will cause the daemon to wake up and
schedule the execution of the cf-agent. In practice, the classes
listed in the list are usually date- and time-based.
The actual execution of cf-agent may be delayed by splaytime,
and may be deferred by promise caching and the value of
ifelapsed. Note also that the effectiveness of the splayclass
function may be affected by changing the schedule.
Type: slist
Allowed input range: (arbitrary string)
Default value:
schedule => { "Min00", "Min05", "Min10", "Min15", "Min20", "Min25",
"Min30", "Min35", "Min40", "Min45", "Min50", "Min55" };
Example:
body executor control
{
schedule => { "Min00", "(Evening|Night).Min15_20", "Min30", "(Evening|Night).Min45_50" };
}
smtpserver
Description: Name or IP of a willing smtp server for sending email
This should point to a standard port 25 server without encryption. If you are running secured or encrypted email then you should run a mail relay on localhost and point this to localhost.
Type: string
Allowed input range: .*
Example:
body executor control
{
smtpserver => "smtp.example.org";
}
splaytime
Description: Time in minutes to splay this host based on its name hash
Whenever any class listed in the schedule attribute is present,
cf-execd can schedule an execution of cf-agent. The actual
execution will be delayed an integer number of seconds between
0-splaytime minutes. The specific amount of delay for "this" host
is based on a hash of the hostname. Thus a collection of hosts will
all execute at different times, and surges in network traffic can
be avoided.
A general rule for scaling of small updates is to set the splay time to
runinterval-1 minutes for up a few thousand hosts. For example, the default
schedule executes once every 5 minutes, so the splay time should be set to no
more than 4 minutes. The splaytime should be set to a value less than the
cf-execd scheduling interval, else multiple clients might contend for data.
In other words, splaytime + cf-agent run time should be less than the
scheduling interval.
Type: int
Allowed input range: 0,99999999999
Default value: 0
The CFEngine default policy sets splaytime to 1.
Example:
body executor control
{
splaytime => "2";
}
See also: The splayclass() function for a task-specific
means for setting splay times.