Sensu Plugin - Check Process

Finds processes matching various filters (name, state, etc). The number of processes found will be tested against the Warning/critical thresholds. This handler formats alerts as emails and sends them off to a pre-defined recipient. [1]

Basic information

  • License: MIT License

Installation

Note

This installation process has to be performed in each Sensu Client that will execute this monitoring task.

Install the plugin executing:

$ sensu-install -p process-checks

It will be located in /opt/sensu/embedded/bin/check-process.rb, that directory is included in the Sensu user PATH, so in the check definition it’s not necessary to write the full path in the configuration file.

Usage

Add the Check-Process configuration, specifying which will be its subscribers.

The -p argument is for a pattern to match against the list of running processes reported by ps. [1]

Example: Checks if there is any process running that contains /usr/sbin/sshd in its name, status, etc from the output of the command ps.

{ "checks":
  {
    "service_sshd": {
      "command": "check-process.rb -p /usr/sbin/sshd",
      "interval": 60,
      "handlers": ["mailer"],
      "subscribers": ["ssh"],
      "standalone": false,
    }
  }
}

Note

It’s important to set correctly the argument to filter correctly from the running processes. Read more in The check shows an incorrect number of running processes.

Troubleshooting

The check shows an incorrect number of running processes

In the previous example of SSH, the specified filter was /usr/sbin/sshd, because the check wanted to know if the service ssh was up.

If the filter is changed to sshd, it will find other ssh processes that are not related to sshd, for example, a remote connection as a client, not as a server. That’s why it’s important to define the filter correctly, and verify that it finds what you really want.

References