Add Action Listing to api

Just as the API allows us to query the available tables that a datasource provides, it should be possible to query the available actions that a datasource can execute.

Problem description

Currently, datasources have the ability to execute actions, but there is no api call to ask what the available actions are.

Proposed change

Add an API call that returns the list of available actions.

This requires adding a method to the congress/datasources/ class that returns the list of actions that the datasource will execute.

It would be nice if the ExecutionDriver also enforced that it only executed the actions in that list.

One might consider trying to auto-generate the list of actions based on the methods available in the python-client being used (for those datasources using a python-client).


The alternative is to provide no API and ask people to consult the documentation to find the list of available actions.

This is more attractive than it sounds because it gives us the freedom to execute any action that the python-client for the underlying datasource exposes. If someone adds a new method for the python-client then a policy writer immediately gets access to that method, without requiring any changes in Congress.

The downside to this approach is that end-users need to understand which python client they are using within each datasource driver and then look up the docs for that python client. So in terms of usability, it’s pretty terrible.



Policy actions


Data sources


Data model impact

There should be no data-model impact, since the added information is implemented as part of the datasource driver, not stored in the database.

REST API impact

GET /v1/data-sources/<datasource-id>/actions

Should error if the datasource does not implement the proper method.

Result should be an array of dicts, where each dict describes an action:
[{‘name’: <action-name>,

‘args’: <list-of-parameter-names>}]

The assignee is free to extend the fields of an action to include additional meta-information, such as a description of what the action does, or a description of what each of the parameters are.

Security impact


Notifications impact


Other end user impact

Need to add similar functionality to the python-congressclient.

Performance impact


Other deployer impact


Developer impact




Primary assignee:

<launchpad-id or None>

Other contributors:

<launchpad-id or None>

Work items

  1. Modify API design doc (linked from the wiki)

  2. Add method to ExecutionDriver in congress/datasources/

  3. Add call handler in congress/

  4. Add route call in congress/api/

  5. Add API implementation to congress/api/

  6. Update python-congressclient




  • Unit tests for API to congress/tests/

  • Unit tests for ExecutionDriver

Documentation impact

Add API call