Refactor MapR plugin code

Refactor MapR plugin code

https://blueprints.launchpad.net/sahara/+spec/mapr-refactor

MapR plugin’s code should be refactored to support easy addition of new services and releases

Problem description

Current plugin implementation has several weaknesses: * Declarative nature of Service * Code complexity caused by usage of plugin-spec.json * Almost all actions are implemented as sequence of utility functions calls * Not clear separation of behaviour to modules and classes * Some code is redundant

Proposed change

  • Extract Service entity to separate class with customizable behaviour
  • Move provisioning logic from utility modules to specialized classes
  • Remove redundant code

MapR plugin implementation delegates all operations to it’s counterparts in VersionHandler interface. VersionHandler interface mimics plugin SPI with additional methods get_context(cluster) and get_services(). ClusterContext object returned by get_context wraps cluster object passed as argument and provides additional information about cluster as well as utility methods related to wrapped cluster.

Service definitions resides in ‘sahara.plugins.mapr.services’ package instead of plugin-spec.json which is completely removed now. Each service definition represents particular version of service.

Alternatives

Leave code “as-is”

Data model impact

None

REST API impact

None

Other end user impact

None

Deployer impact

None

Developer impact

Developers of subsequent versions of the MapR plugin should take into account this changes.

Sahara-image-elements impact

None

Sahara-dashboard / Horizon impact

None

Implementation

Assignee(s)

Primary assignee:
aosadchiy
Other contributors:
ssvinarchuk

Work Items

  1. Extract Service entity to separate class with customizable behaviour
  2. Move provisioning logic from utility modules to specialized classes
  3. Remove redundant code

Dependencies

None

Testing

Existing integration tests are sufficient

Documentation Impact

None

References

None

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.

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