With remote commands you can define that a certain pre-defined command is automatically executed on the monitored host upon some condition.
Thus remote commands are a powerful mechanism for smart pro-active monitoring.
In the most obvious uses of the feature you can try to:
Configuring an action for remote commands is similar to that for sending a message, the only difference being that Zabbix will execute a command instead of sending a message.
Remote commands can be executed by Zabbix server, proxy or agent. Remote commands on Zabbix agent can be executed directly by Zabbix server or through Zabbix proxy. Both on Zabbix agent and Zabbix proxy remote commands are disabled by default. They can be enabled by:
AllowKey=system.run[*]parameter in agent configuration;
Remote commands executed by Zabbix server are run as described in Command execution including exit code checking.
Remote commands are executed even if the target host is in maintenance.
Remote command limit after resolving all macros depends on the type of database and character set (non- ASCII characters require more than one byte to be stored):
|Database||Limit in characters||Limit in bytes|
|SQLite (only Zabbix proxy)||65535||not limited|
The following tutorial provides step-by-step instructions on how to set up remote commands.
Those remote commands that are executed on Zabbix agent (custom scripts) must be first enabled in the agent configuration.
Make sure that the AllowKey=system.run[<command>,*] parameter is added for each allowed command in agent configuration to allow specific command with nowait mode. Restart agent daemon if changing this parameter.
Remote commands do not work with active Zabbix agents.
Then, when configuring a new action in Alerts → Actions → Trigger actions:
Scripts that are available for action operations (webhook, script, SSH, Telnet, IPMI) are defined in global scripts.
In this case, Zabbix will try to restart an Apache process. With this command, make sure that the command is executed on Zabbix agent (click the Zabbix agent button against Execute on).
Note the use of sudo - Zabbix user does not have permissions to restart system services by default. See below for hints on how to configure sudo.
Zabbix agent should run on the remote host and accept incoming connections. Zabbix agent executes commands in background.
Remote commands on Zabbix agent are executed without timeout by the system.run[,nowait] key and are not checked for execution results. On Zabbix server and Zabbix proxy, remote commands are executed with timeout as set in the TrapperTimeout parameter of zabbix_server.conf or zabbix_proxy.conf file and are checked for execution results.
Make sure that the 'zabbix' user has execute permissions for configured commands. One may be interested in using sudo to give access to privileged commands. To configure access, execute as root:
Example lines that could be used in sudoers file:
# allows 'zabbix' user to run all commands without password. zabbix ALL=NOPASSWD: ALL # allows 'zabbix' user to restart apache without password. zabbix ALL=NOPASSWD: /etc/init.d/apache restart
On some systems sudoers file will prevent non-local users from executing commands. To change this, comment out requiretty option in /etc/sudoers.
If the target system has multiple interfaces of the selected type (Zabbix agent or IPMI), remote commands will be executed on the default interface.
It is possible to execute remote commands via SSH and Telnet using another interface than the Zabbix agent one. The available interface to use is selected in the following order:
For IPMI remote commands the following syntax should be used:
Examples of global scripts that may be used as remote commands in action operations.
Restart of Windows on certain condition.
In order to automatically restart Windows upon a problem detected by Zabbix, define the following script:
|Command||c:\windows\system32\shutdown.exe -r -f|
Restart the host by using IPMI control.
Power off the host by using IPMI control.