Plugin format

Rudder has a specific package format for plugins.

You can manage Rudder packages with the rudder-pkg command. This is the documentation of how they are created.

File description

A Rudder package file ends with the .rpkg extension.

A Rudder package file is an archive file and can be managed with the 'ar' command.

The archive contains:

  • A metadata file in JSON format named medatata

  • A tarball file in txz format name scripts.txz that contains package setup utility scripts

  • One or more tarball files in txz format that contain the package files

The metadata file is a JSON file and is named 'metadata':

{
  # the only currently supported type in "plugin" (mandatory)
  "type": "plugin",
  # the package name must consist of ascii characters without whitespace (mandatory)
  "name": "myplugin",
  # the package version has the form "rudder_major-version_major.version_minor" for a plugin (mandatory)
  "version": "4.1-1.0",
  # these are is purely informative (optional)
  "build-date": "2017-02-22T13:58:23Z",
  "build-commit": "34aea1077f34e5abdaf88eb3455352aa4559ba8b",
  # the list of jar files to enable if this is a webapp plugin (optional)
  "jar-files": [ "test.jar" ],
  # the list of packages or other plugins that this package depends on (optional)
  # this is currently only informative
  "depends": {
    # dependency on a specific binary that must be in the PATH
    "binary": [ "zip" ]
    # dependencies on dpkg based systems
    "dpkg": [ "apache2" ],
    "rpm": [ ],
    # dependency specific to debian-8
    "debian-8": [ ],
    "sles-11": [ ],
    # rudder dependency, ie this is a Rudder format package
    "rudder": [ "new-plugin" ]
  },
  # the plugin content (mandatory)
  "content": {
    # this will put the content of the extracted files.txz into /opt/rudder/share
    "files.txz": "/opt/rudder/share",
    "var_rudder.txz": "/var/rudder"
  }
}

To see a package metadata file use:

ar p package.rpkg medatada

The scripts.txz is a tarball that can contain zero or more executable files named:

  • preinst that will be run before installing the package files

  • postinst that will be run after installing the package files

  • prerm that will be run before removing the package files

  • postrm that will be run after removing the package files

preinst and postinst take one parameter that can be 'install' or 'upgrade'. The value 'upgrade' is used when a previous version of the package is already installed.

To create the scripts.txz file use:

tar cvfJ scripts.txz preinst postinst prerm postrm

To create a Rudder package file use the ar command:

ar r mypackage-4.1-3.0.rpkg medatada scripts.txz files.txz

Note that ar r inserts or replaces files so you can create your package with incremental inserts.

To extract files, use ar x instead.


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