Script API

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Revision as of 21:35, 12 May 2008 by Dustin (talk | contribs) (Pre&Post script API moved to Pre and Post Scripts: general topic, not just an API)
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Introduction

Pre- and post-scripts are use to execute scripts before or after certain amanda commands. The scripts can be executed on the client or server, once for each DLE or once for each client host. Uses for pre- and post-scripts include:

  • to stop and start database servers so that the binary backup is consistent
  • to take a snapshot of a database
  • to send emails or other notifications

Script calling convention

This is subject to change

 /path/to/script [execute-on]+ [--config <config>] [--host <host>] [--disk <disk>] [--device <device>]

 input of fd0:
   tool property (see below)
 output on fd1
   free format, will go to the amanda debug file.

execute-on is a comma-separated list of one or more words of the form (pre|post)-(dle|host)-(selfcheck|estimate|backup). The whole list is:

 pre-dle-selfcheck
 pre-host-selfcheck
 post-dle-selfcheck
 post-host-selfcheck
 pre-dle-estimate
 pre-host-estimate
 post-dle-estimate
 post-host-estimate
 pre-dle-backup
 pre-host-backup
 post-dle-backup
 post-host-backup

The disk and device arguments to the script are provided only if the script is executed for a DLE.

tool property format

Each property is on one line, the property name followed by all values of the property:

 property_name [property_value]+

They are quoted string if needed.

How to use

Scripts are defined in amanda.conf, and then referenced from a dumptype.

Define the script in amanda.conf

Define the "my_script" script using the "myscript" binary.

 define script-tool my-script {
    "script-base"                       # inherit config of the script-base script-tool
    comment "a comment"
    plugin  "myscript"                # filename of the script, in the dumper dir
    execute-where server              # or client
    execute-on    pre-dle-backup
    property "mailto" "amandabackup"  # can set arbitrary properties
 }

Use the script in a dumptype

Reference the script-tool with the script parameter:

 define dumptype user-tar-scripted {
   user-tar
   script "my-script"
 }

Note that the dumptype declaration must be below the script-tool declaration in the configuation file.

Email example

 define script-tool sc-email {
   comment "email me before this DLE is backed up"
   plugin  "script-email"
   execute-on pre-dle-backup
   execute-where server
   property "mailto" "martinea"
 }

 define dumptype user-tar-email {
   user-tar
   script "sc-email"
 }

Complex Examples

Just as you can include dumptypes in a DLE, you can include script-tool definitions in a dumptype:

 define dumptype user-tar-email2 {
   user-tar
   script {
     "sc-email"
     execute-where client
     execute-on    post-dle-backup, post-host-estimate
   }
 }

You can even combine all of this in a DLE:

myhost /my/disk {
   user-tar
   script {
     "sc-email"
     execute-where client
     execute-on    post-dle-backup, post-host-estimate
   }
} -1 local