DDPB 2645 rollback procedure

[alexeves]

Purpose

An initial document which proposes a suitable rollback procedure for infrastructure, application, and database.

Addresses DDPB-2645

Approach

This is an initial outline which has yet to be fully replicated. The database migration proposal has been verified against the develop database. The rollback of code uses existing Jenkins tools and scripts.

Learning

Given that the only variable when applying any Doctrine down migrations is the filename of the migration file to revert to, it seems feasible that we could automate the migration command execution via a parameterised Jenkins task.

Checklist

• I have performed a self-review of my own code
• I have updated documentation (Confluence/GitHub wiki) where relevant
• [N/A] I have added tests to prove my work, and they follow our best practices
• [N/A] I have successfully built my branch to a feature environment
• [N/A] New and existing unit tests pass locally with my changes (docker-compose run --rm api sh scripts/apiunittest.sh)
• [N/A] There are no Composer security issues (docker-compose run api php app/console security:check)
• [N/A] The product team have tested these changes

[hansnqyr]

As an aside I'd like to see us tidy up our migrations to remove those unnecessary create schema statements

[gregtyler]

As an aside I'd like to see us tidy up our migrations to remove those unnecessary create schema statements

You're in luck: #551