Add loose foreign key preparation for DAST [RUN ALL RSPEC] [RUN AS-IF-FOSS]

ROLLBACK steps

There is a small chance that the introduced DB triggers will cause performance degradation (slower deletion speed). If this becomes a big problem (incident), then we can mitigate it by dropping the triggers. Dropping the triggers is safe.

SET lock_timeout='3s';  -- attempt short lock waits

-- During busy hours, we might need to retry these statements a few times until they succeed:
DROP TRIGGER ci_builds_loose_fk_trigger ON ci_builds;
DROP TRIGGER ci_pipelines_loose_fk_trigger ON ci_pipelines;

What does this MR do?

This merge request prepares dast for loose foreign keys. This MR only sets up the deletion tracking, the removal of the foreign keys will happen later.

Related Issue(s)

• Drop CI Pipeline and CI Build DAST Foreign Keys

Database

Migrations

% rails db:migrate:up VERSION=20211027043206 && rails db:migrate:up VERSION=20211027043229
== 20211027043206 TrackCiPipelineDeletions: migrating =========================
-- execute("CREATE TRIGGER ci_pipelines_loose_fk_trigger\nAFTER DELETE ON ci_pipelines REFERENCING OLD TABLE AS old_table\nFOR EACH STATEMENT\nEXECUTE FUNCTION insert_into_loose_foreign_keys_deleted_records();\n")
   -> 0.0033s
== 20211027043206 TrackCiPipelineDeletions: migrated (0.0034s) ================

== 20211027043229 TrackCiBuildDeletions: migrating ============================
-- execute("CREATE TRIGGER ci_builds_loose_fk_trigger\nAFTER DELETE ON ci_builds REFERENCING OLD TABLE AS old_table\nFOR EACH STATEMENT\nEXECUTE FUNCTION insert_into_loose_foreign_keys_deleted_records();\n")
   -> 0.0029s
== 20211027043229 TrackCiBuildDeletions: migrated (0.0031s) ===================

% rails db:migrate:down VERSION=20211027043229 && rails db:migrate:down VERSION=20211027043206
== 20211027043229 TrackCiBuildDeletions: reverting ============================
-- execute("DROP TRIGGER IF EXISTS ci_builds_loose_fk_trigger ON ci_builds")
   -> 0.0026s
== 20211027043229 TrackCiBuildDeletions: reverted (0.0027s) ===================

== 20211027043206 TrackCiPipelineDeletions: reverting =========================
-- execute("DROP TRIGGER IF EXISTS ci_pipelines_loose_fk_trigger ON ci_pipelines")
   -> 0.0024s
== 20211027043206 TrackCiPipelineDeletions: reverted (0.0025s) ================

Screenshots or Screencasts (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team