Enable and Execute Event Scripts

Store Event Scripts

Event scripts are stored on a device’s hard disk in the /var/db/scripts/event directory or on the flash drive in the /config/scripts/event directory. Only users in the super-user login class can access and edit files in these directories. For information about setting the storage location for scripts, see Store and Enable Junos Automation Scripts and Store Scripts in Flash Memory.

To prevent the execution of unauthorized Python code on Junos devices, unsigned Python scripts must meet certain requirements before you can execute the scripts on a device. Unsigned Python scripts must be owned by either root or a user in the super-user login class, and only the file owner can have write permission for the file. For detailed information about the requirements for executing Python automation scripts, see Requirements for Executing Python Automation Scripts on Junos Devices.

Note:

If the device has dual Routing Engines and you want to enable an event script to execute on both Routing Engines, you can copy the script to the /var/db/scripts/event or /config/scripts/event directory on both Routing Engines, or you can issue the commit synchronize scripts command to synchronize the configuration and copy the scripts to the other Routing Engine as part of the commit operation.

Enable Event Scripts

You must enable an event script before you can execute it. To enable an event script, include the file filename statement at the [edit event-options events-script] hierarchy level, and specify the filename of the event script. Only users in the super-user login class can enable event scripts.

SLAX and Python scripts must include the .slax or .py filename extension, respectively, in both the actual script name and the filename in the configuration. XSLT scripts do not require a filename extension, but we strongly recommend that you append the .xsl extension. In either case, the configured filename must exactly match the filename of the script in the directory. For example, if the XSLT script filename is script1.xsl, then you must include script1.xsl in the configuration. Likewise, if the XSLT script filename is script1, then you must include script1 in the configuration.

By default, you cannot execute unsigned Python scripts on Junos devices. To enable the execution of unsigned Python automation scripts that meet the requirements outlined in Requirements for Executing Python Automation Scripts on Junos Devices, you must configure the language python or language python3 statement at the [edit system scripts] hierarchy level.

To determine which event scripts are currently enabled on the device, display the files configured at the [edit event-options event-script] hierarchy level.

To ensure that the enabled files are on the device, list the contents of the /var/run/scripts/event/ directory.

When you issue the commit command, the system places any event scripts configured at the [edit event-options event-script] hierarchy level into system memory and enables them for execution. After the commit operation completes, an event policy can execute an event script in response to an event notification.

Event Script Access Privileges

By default, Junos devices execute SLAX and XSLT event scripts using the root user and execute Python event scripts with the access privileges of the generic, unprivileged user and group nobody. You can configure event scripts to execute with the access privileges of a specific user. The statement to configure the access privileges depends on the script language.

To execute SLAX and XSLT event scripts with the access privileges of a specific user instead of the root user, configure the user-name statement for the event policy action that invokes the script.

To execute a Python event script under the access privileges of a specific user, configure the python-script-user username statement at the [edit event-options event-script file filename] hierarchy level. You cannot configure Python event scripts to execute with root access privileges.

Note:

To enable a user who does not belong to the file’s user or group class to execute an unsigned Python automation script, the script’s file permissions must include read permission for others.

Example: Enable an Event Script

To enable an event script:

1. Place the script in the appropriate directory:

   • /var/db/scripts/event directory on the hard disk

   • /config/scripts/event directory on the flash drive

2. If you store scripts on the flash drive, configure the load-scripts-from-flash statement.

3. For unsigned Python scripts, ensure that the following requirements are met:

   • File owner is either root or a user in the super-user login class.

   • Only the file owner has write permission for the file.

   • The language python or language python3 statement is configured at the [edit system scripts] hierarchy level.

4. Enable the script.

   For example:

5. For Python scripts, configure the script to execute under the access privileges of a specific user.

   Configure a user with a local user account. You cannot configure the root user.

   For example:

6. Commit the configuration.