Horizon unable to show details for some policy tables

[Janet Yu]

Clicking on one of the Policy Data Table Name column links in the Data Sources page results in an error about being unable to get the schema for the table, when the table name looks like <datasource>:<tablename> and <tablename> is not actually a table in <datasource>. This table name format is needed for action names, to indicate on which service to execute the action.

When Horizon doesn't find <tablename> in <datasource>, it should proceed with using the entire <datasource>:<tablename> string as the name of a policy table.

[Aimee Ukasick (aimeeu)]

This may be related to https://bugs.launchpad.net/congress/+bug/1602837

[Eric K (ekcs)]

To reproduce (assuming there is a datasource named 'nova'):

$ openstack congress policy create policy1
$ openstack congress policy rule create policy1 'p(x) :- nova:q(x)'

Then navigate to the 'policy1' policy, scroll down to click on the table 'nova:q' in under 'Policy Table Data'

To obtain the error:
Error: Unable to get rows in table "nova:q", data source "policy1": Internal Server Error::Known table but unknown arity for 'nova:q' in policy 'policy1' (HTTP 500) (Request-ID: req-b9712b75-5b4f-4d93-8e91-b26f05eb5543)