Fuel Plugins

Starting with version 6.0, Fuel supports a Pluggable architecture.

Fuel plugins allow you to install and configure additional capabilities for your cloud, such as additional storage types and networking functionality. For example, a Load Balancing as a Service (LBaaS) plugin allows you to add network load balancing functionality to your cloud so that incoming traffic can be spread across multiple nodes. Or you might want to use a GlusterFS plugin so that you can use a Gluster file system as backend for Cinder volumes.

Finding Plugins

For production versions of plugins, including certified plugins, see Released Plugins Catalog.

For instructions on installing Fuel plugins, see Installing Plugins.

Finding documentation

You can find Fuel Plugins documentation in the following sources:

• Development issues - Plugins Wiki page.
• Common installation instructions - Install Fuel Plugins and CLI command reference sections in the User Guide.
• Specific installation instructions - Fuel Plugins Catalog.

OpenStack Fuel-plugins Repository

This repository contains plugin example, and the Fuel plugin builder tool (fpb). The plugin code here might not be suitable for production use please see Released Plugins Catalog to download release versions of these and other Fuel plugins.

Creating your own plugins

Detailed instructions can be found in the Plugins Wiki page.

Plugins should be built using the fuel-plugin-builder (fpb) utility found in this repoistory or via pip. fpb will ensure that build steps as well as validation is performed prior to assembling a package.

Abbreviated instructions:

pip install fuel-plugin-builder
fpb --create fuel_plugin_name
fpb --build <path to plugin>

This will:

• install fuel-plugin-builder
• clone the fuel_plugin_example plugin with the name fuel_plugin_name
• build the plugin .rpm package.

This is not working on my OS

You could find an example of docker setup creating and building plugin in shared library running:

tox -edocker

How Fuel plugin builder works

Fuel plugin builder entry point is ./cli.py file that provides cli command bindings to the ./actions.

Two actions are available:

• create Creating bootstrap plugin file structure using files combining templates/* folders defined in ./versions_mapping.py
• build Build plugin package using working directory.

Build involving 5 steps with according modules responsive for this step for given plugin package version.

• Preloading (single for all)
• Loading
• Validation
  • Data schema checking
• Package Build

Preloading is about opening metadata.yaml, looking for package version and choosing appropriate classes using ./version_mapping.py

Loading is performed by Loader class of given version that are know where to look for files how understand their formats, how resolve external references inside data. Loader output is a list/dict tree with metadata.yaml content as root. Loading report tree is attached to this list/dict structure and based on report status FPB deciding to continue build process or reject it providing failure report to developer.

Validation is performed by one of Validator classes located at ./validators folder, and taking list/dict data tree as input. Validator business logic taking data tree at parts and applying @check functions to this branches making report tree (consist of ReportNode) as output.

JSON Schema checks is the part of validation when we are getting sure that form of data tree branches or whole tree is valid. We are making plugins for Fuel so the data structure schemas is relying on fuel versioning (starting from v6.0) so you could easily express with which Fuel version your package validation should be compatible with. You could see this schemas located at ./schemas folder.

Building itself is a copying of files preserving their permissions and making rpm package based on metadata.yaml of your plugin, command line arguments and plugin_rpm.spec.mako with path defined in rpm_spec_src_path builder attribute resolved with this context to plugin_rpm.spec file.

All validation and loading processes are producing reports. Reports are the tree of ReportNode() instances. You could write messages with report_node.error('ERROR!'), report_node.warning('Warning!'), report_node.info('Info') attach one nodes to another with report_node.add_nodes(ReportNode('Im a child!'), ReportNode('Im too!')) And, what is the best option, you could render every tree branch as text log yaml and json documents just calling print report_branch_node.render('yaml').

How FPB and Fuel versions are aligned?

Fuel Plugin Builder <-> Fuel versions mapping:

Fuel FPB Tasks

6.0 - 1.0.0 - 0.0.0 6.0 - 1.0.1 - 0.0.0 6.0 - 1.0.2 - 0.0.1 6.1 - 2.0.0 - 1.0.0 6.1 - 2.0.1 - 1.0.0 6.1 - 2.0.2 - 1.0.0 6.1 - 2.0.3 - 1.0.0 6.1 - 2.0.4 - 1.0.0 6.1 - 2.0.4 - 1.0.0 7.0 - 3.0.0 - 1.0.1 8.0 - 4.0.0 - 2.0.0 8.0 - 4.1.0 - 2.1.0 9.1 - 5.0.0 - 2.2.0

Examples

Simple Fuel plugin examples you can find here:

https://github.com/openstack/fuel-plugins/tree/master/examples

Other Plugin repositories

Other locations known to have Fuel plugins. Note, these may not be supported by the Fuel team

• Community Plugins