COST-716: Finalizing GCP sources and supporting app-specific settings for AWS and Azure

[dccurtis]

GCP integration changes are coded against: RedHatInsights/sources-api#299 which should be merging today.

UPDATE:

• Change merged and it works great against this PR

The sources team agreed to use the new Applications.extra value to hold the dataset (was previously using PATCH). This change also brings along support for AWS and Azure to also use the new extra field while at the same time maintaining backwards compatibility with PATCH for AWS and Azure. Data migrations in all environments must happen before we decommission the PATCH path for AWS and Azure.

Testing

1. Regression test AWS source creation with PATCH
2. Regression test Azure source creation with PATCH
3. Add AWS source with Application-extra flow
4. Add Azure source with Application-extra flow
5. Update AWS bucket for source_id =3 (Application.extra path) to an incorrect bucket and verify status is updated accordingly
6. Add GCP source (using WIP sources branch) with an invalid project name (verify status is correct). Fix project name and verify source is created successfully.

Test Results
cost_716_ut.txt

[codecov]

Codecov Report

Merging #2609 (93446d9) into master (0bf63d7) will decrease coverage by 0.1%.
The diff coverage is 89.2%.

@@           Coverage Diff            @@
##           master   #2609     +/-   ##
========================================
- Coverage    94.8%   94.7%   -0.1%     
========================================
  Files         281     281             
  Lines       21230   21327     +97     
  Branches     2412    2432     +20     
========================================
+ Hits        20123   20203     +80     
- Misses        665     673      +8     
- Partials      442     451      +9     

[dccurtis]

E2E Deploy update for GCP:
https://github.com/RedHatInsights/e2e-deploy/pull/2678

[maskarb]

LGTM!