Admin API for Managing Plugins

Admin API for Managing Plugins

https://blueprints.launchpad.net/sahara/+spec/plugin-management-api

This is a proposal to implement new admin API for management plugins for different projects. Also, smarter deprecation can be implemented with a new management API for plugins.

Problem description

Right now we have the following problems:

  • plugin state is totally unclear for user. From the user point of view, there are only default plugins, which are enabled for all projects;
  • deprecation of the particular plugin version is not perfect right now: validation error with deprecation note will be raised during creation - which is not so good for user;
  • all plugins and versions are enabled for all projects, which is not perfect. Someone wants to use only Ambari plugin, and other one wants to use only CDH plugin (or a particular version)

Proposed change

It’s proposed to implement several new API calls for plugins management. Actually, there is plan to support that in API v1.1 correctly so that we can put this to API v2 without additional stuff.

First of all we need to enable all plugins by default. There is no sense to continue separating default and non-default plugins. There is an agreement that having default/non-default plugins is redundant, just because such process don’t allow to deliver probably non-stable plugins at least for testing in several projects.

Additionally as a part of this blueprint migration of hadoop_version to plugin_version should be done to keep this api consistent with new management API.

New database should be created to store all required metadata about current state of each plugin. This metadata is a combination of labels for plugins itself and for each version of the plugin. The plugin label is an indicator of plugin state (or version) that we will help user to understand the current state of plugin itself (like a stability, deprecation status) or of some features. If no metadata will be stored in DB, plugin SPI method will help us to return default metadata for plugin. This also will help us to avoid possible issues with upgrades from old releases of sahara.

This metadata should describe each plugin and its versions. The example of return value of this plugin SPI method is the following:

{
   "version_labels": {
       "2.3": {
           "stable": {
               "status": true
           },
           "enabled": {
               "status": true
           }
       },
       "2.2": {
           "deprecated": {
               "status": true
           },
           "enabled": {
               "status": true
           }
       }
   },
   "plugin_labels": {
       "enabled": {
           "status": false,
       }
   }
}

PluginManager on requests of all plugins will collect all data stored in DB for plugins and will accumulate that data with default data for plugins without entry in DB. Also, for each label entry manager will additionally put the description of the label and possibility of changing of label by admins. The collected data will be exposed to the user. See example of return value below in REST API section.

The initial set of labels is the following:

  • enabled if plugin is enabled, then each user will be able to use plugin for cluster creation and will have ability to perform all CRUD operations on top the cluster. If plugins doesn’t have this label, only deletion can be performed with this cluster.
  • hidden if plugin is hidden, it’s still available for performing actions using saharaclient, but it will be hidden from UI side and CLI. It’s special tag for fake plugin.
  • stable plugin is stable enough to be used. Sahara CI should be enabled for plugin to prove it’s stability in terms of cluster creation and running EDP jobs. This label can’t be removed. Will not be stored in DB and will be handled by plugin SPI method only.
  • deprecated plugin is deprecated. Warnings about deprecation will be shown for this plugin. Not intended to be used. Sahara CI (nightly) will continue testing this plugin to prove it’s still works well. Label can’t be removed. Recommendations should be provided about what operations are available for this cluster.

Admin user will be able to perform PATCH actions with labels via API, if label is really can be removed. oslo_policy will be used for handling that user have admin role. Only status can be changed for each label. Mutability and description can’t be changed.

Alternatives

None

Data model impact

New table is needed for this feature to store data about plugin tags.

+----------------+--------------+
| plugins        | column type  |
+----------------+--------------+
| tenant_id      | String       |
+----------------+--------------+
| plugin_labels  | JsonDictType |
+----------------+--------------+
| version_labels | JsonDictType |
+----------------+--------------+
| id (Unique)    | String       |
+----------------+--------------+
| name           | String       |
+----------------+--------------+

An simple example of stored data:

{
   'name': "fake",
   "plugin_labels": {
       "enabled": {
           "status": true,
       }
   },
   "tenant_id": "uuid",
   "id": "uuid just to be unique",
   "version_labels": {
       "0.1": {
           "enabled": {
               "status": true
           }
       }
   }
}

REST API impact

There are bunch of changes in REST API are going to be done.

Endpoint changes:

  1. for GET /plugins to following output will be expected after implementation. All labels will be additionally serialized with description, mutability.
{
   "plugins": [
       {
           "description": "HDP plugin with Ambari",
           "versions": [
               "2.3",
               "2.4",
           ],
           "name": "ambari",
           "plugin_labels": {
               "enabled": {
                   "description": "Indicates that plugin is switched on",
                   "mutable": true,
                   "status": true
               }
           },
           "version_labels": {
               "2.3": {
                   "enabled": {
                       "description": "Indicates that version is switched on",
                       "mutable": true,
                       "status": false,
                   },
                   "deprecated": {
                       "description": "Plugin is deprecated, but can be used"
                       "mutable": false,
                       "status": true
                   },
                   "stable": {
                       "description": "Plugin stability",
                       "mutable": false,
                       "status": false
                   }
               },
               "2.4": {
                   "enabled": {
                       ..
                   },
                   "stable": {
                       ..
                   },
               },
           },
           "title": "HDP Plugin"
       },
   ]
}
  1. new PATCH /plugins/<name> which is intended for updating tags for plugin or/and its versions. Update will be done successfully if all modified labels are mutable. Validation will be done for user if updating only status of each labels. To update a label you need to send request with only this label in body. Mutability and description are fields that can’t be changed.
{
   "plugin_labels": {
       "enabled": {
           "status": false,
       }
   }
   "version_labels: {
       "2.3": {
           "enabled": {
               "status": true,
           },
       },
       "2.4": {
           "enabled": {
               "status": false,
           },
       },
   }
}

Other end user impact

New CLI will be extended with plugin updates. Warnings about deprecation label will be added too.

Deployer impact

Nothing additional is required from deployers; anyway we should notify about new default value for plugins option.

Developer impact

None

Sahara-image-elements impact

None

Sahara-dashboard / Horizon impact

Things to do:

  1. New tab for management plugins should be implemented. All labels will be shown in this tab. Each label will have checkboxes that will add this label to plugin. Only admin will have ability to produce changes.
  2. Warning regarding deprecation label will be added to templates/cluster creation tabs. If the only plugin enabled we will not have dropdown for plugin choice, and the same thing for version. If the only plugin and version is enabled, plugin choice action will be skipped.

Implementation

Assignee(s)

Primary assignee:
vgridnev (Vitaly Gridnev)

Work Items

The following items should be covered:

  • enable all plugins by default;
  • implement database side;
  • new API methods should be added;
  • plugin SPI method for default metadata;
  • document new api features in API docs;
  • python-saharaclient implementation;
  • sahara-dashboard changes

Dependencies

Depends on OpenStack requirements

Testing

Feature will covered by unit tests.

Documentation Impact

All plugin labels should be documented properly.

References

None

Creative Commons Attribution 3.0 License

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