Creating a Murano plug-in

Murano plug-in is a setuptools-compliant python package with setup.py and all other necessary files. For more information about defining stevedore plug-ins, see stevedore documentation.

The structure of the demo application package

The package must meet the following requirements:

  • It must be a ZIP archive.

  • The root folder of the archive must contain a manifest.yaml file.

  • The manifest must be a valid YAML file representing key-value associative array.

  • The manifest should contain a Format key, that is, a format identifier. If it is not present, “MuranoPL/1.0” is used.

Murano uses the Format attribute of the manifest file to find an appropriate plug-in for a particular package type. All interactions between the rest of Murano and package file contents are done through the plug-in interface alone.

Because Murano never directly accesses files inside the packages, it is possible for plug-ins to dynamically generate MuranoPL classes on the fly. Those classes will be served as adapters between Murano and third-party systems responsible for deployment of particular package types. Thus, for Murano all packages remain to be of MuranoPL type though some of them are “virtual”.

The format identifier has the following format: Name/Version. For example, Heat.HOT/1.0. If name is not present, it is assumed to be MuranoPL (thus 1.0 becomes MuranoPL/1.0). Version strings are in SemVer three-component format (major.minor.patch). Missing version components are assumed to be zero (thus 1.0 becomes 1.0.0).

Installing a plug-in

To use a plug-in, install it on murano nodes in the same Python environment with murano engine service.

To install a plug-in:

  1. Execute the plug-in setup script.

    Alternatively, use a package deployment tool, such as pip:

    cd plugin_dir
pip install .

  2. Restart murano engine. After that, it will be possible to upload and deploy the applications that use the capabilities that a plug-in provides.

Plug-in versioning

Plug-ins located in Murano repository have the same version as Murano. Therefore, to use a specific version of such plug-in, checkout to this version. Then specify the version of plug-in classes in your application’s manifest file as usual:

Require:
  murano.plugins.example: 2.0.0

It should be standard SemVer format version string consisting of three parts: Major.Minor.Patch. For more information about versioning, refer to Versioning.

Note

Enable Glare to use versioning.

Organization

Documentation

Documentation helps users understand what your plug-in does. For plug-ins located in the Murano repository, create a README.rst file in the main folder of the plug-in. The README.rst file may contain information about the plug-in and an installation guide.

Code

The code of your plug-in may be located in the following repositories:

  • Murano repository. In this case, the plug-in should be located in the murano/contrib/plugins folder.

  • A separate repository. In this case, create your own project.

Bugs

All bugs for specific plug-ins are reported in their projects. Bugs related to plug-ins located in Murano repository should be reported in the Murano project.