Puppet agent on *nix systems
Puppet agent is the application that manages the configurations on your nodes. It requires a Puppet primary server to fetch configuration catalogs from.
Depending on your infrastructure and needs, you can manage systems with Puppet agent as a service, as a cron job, or on demand.
For more information about running the
puppet agent command, see the puppet agent man page.
Puppet agent's run environment
Puppet agent runs as a specific user, (usually
root) and initiates outbound connections on port
Puppet’s HTTPS traffic uses port 8140. Your operating system and firewall must allow Puppet agent to initiate outbound connections on this port.
If you want to use a non-default port, you have to change the serverport setting on all agent nodes, and ensure that you change your primary Puppet server’s port as well.
Puppet agent runs as
root, which lets it manage the
configuration of the entire system.
Puppet agent can also run as a non-root user, as long as it is started by that user. However, this restricts the resources that Puppet agent can manage, and requires you to run Puppet agent as a cron job instead of a service.
If you need to install packages into a directory
controlled by a non-root user, use an
exec to unzip a tarball or use a
file resource to copy a directory into place.
When running without root permissions, most of Puppet’s resource providers cannot use
sudo to elevate
permissions. This means Puppet can only manage
resources that its user can modify without using
||Only non-root cron jobs can be viewed or set.|
||Cannot run as another user or group.|
||Only if the non-root user has read/write privileges.|
||For services that don’t require root.
You can also use the
Manage systems with Puppet agent
In a standard Puppet configuration, each node periodically does configuration runs to revert unwanted changes and to pick up recent updates.
- Run Puppet agent as a service.
- The easiest method. The Puppet agent daemon does configuration runs at a set interval, which can be configured.
- Make a cron job that runs Puppet agent.
- Requires more manual configuration, but a good choice if you want to reduce the number of persistent processes on your systems.
- Only run Puppet agent on demand.
- You can also deploy MCollective to run on demand on many nodes.
Choose whichever one works best for your infrastructure and culture.
Run Puppet agent as a service
puppet agent command can start a long-lived daemon process that does
configuration runs at a set interval.
Start the service.
The best method is with Puppet agent’s init script / service configuration. When you install Puppet with packages, included is an init script or service configuration for controlling Puppet agent, usually with the service name
puppet(for both open source and Puppet Enterprise).In open source Puppet, enable the service by running this command:
sudo puppet resource service puppet ensure=running enable=trueYou can also run the
sudo puppet agentcommand with no additional options which causes the Puppet agent to start running and daemonize, however you won’t have an interface for restarting or stopping it. To stop the daemon, use the process ID from the agent’s
sudo kill $(puppet config print pidfile --section agent)
(Optional) Configure the run interval.
The Puppet agent service defaults to doing a configuration run every 30 minutes. You can configure this with the
# /etc/puppetlabs/puppet/puppet.conf [agent] runinterval = 2h
If you don’t need frequent configuration runs, a longer run interval lets your primary Puppet server handle many more agent nodes.
Run Puppet agent as a cron job
Run Puppet agent as a cron job when running as a non-root user.
setting is set to
true, the Puppet agent
command does one configuration run and then quits. If the
daemonize setting is set
the command stays in the foreground until the run is finished. If set
does the run in the background.
This behavior is good for
building a cron job that does configuration runs. You can use the
splaylimit settings to keep the primaryPuppet server from getting overwhelmed, because the
system time is probably synchronized across all of your agent nodes.
The above example runs Puppet one time every hour.
sudo puppet resource cron puppet-agent ensure=present user=root minute=30 command='/opt/puppetlabs/bin/puppet agent --onetime --no-daemonize --splay --splaylimit 60'
Run Puppet agent on demand
Some sites prefer to run Puppet agent on-demand, and others use scheduled runs along with the occasional on-demand run.
You can start Puppet agent runs while logged in to the target system, or remotely with Bolt or MCollective.
ssh firstname.lastname@example.org sudo puppet agent --test
Disable and re-enable Puppet runs
Whether you’re troubleshooting errors, working in a maintenance window, or developing in a sandbox environment, you might need to temporarily disable the Puppet agent from running.
To disable the agent, run:
sudo puppet agent --disable "<MESSAGE>"
To enable the agent, run:
sudo puppet agent --enable
Configuring Puppet agent
The Puppet agent comes with a default configuration that you might want to change.
Logging for Puppet agent on *nix systems
When running as a service, Puppet agent
logs messages to syslog. Your syslog configuration determines where
these messages are saved, but the default location is
/var/log/messages on Linux, and
/var/log/system.log on Mac OS X.
You can adjust how verbose the logs are with the
log_level setting, which defaults
When running in the foreground with the
--test options, Puppet agent logs directly to the
terminal instead of to syslog.
When started with the
<FILE> option, Puppet agent logs to the file