Automate post-deployment steps (Feature Flags & Data Migrations)

[jhenderson]

Context

This PR introduces automation for our post-deployment steps to ensure that database migrations and feature flag toggles are executed consistently as part of our deployment pipeline.

Currently, we rely on manual execution of these steps after a release. We have recently experienced incidents where feature flags were accidentally left disabled.

Ticket: MAV-4101

What’s changed

• Add data_migrate gem to support running data migrations in the deployment workflow
• Update deploy.yml to run the data migrations in a post-deploy job
• Took the opportunity to backfill a new column NotifyLogEntry#purpose using this gem instead of having to do it manually

What the logging should look like on CloudWatch

Rails -- { event: "data_migration_start", migration: "BackfillPurposeForNotifyLogEntries", total_records: 10, total_batches: 1 }

Rails -- { event: "data_migration_batch", migration: "BackfillPurposeForNotifyLogEntries", records_updated: 10, batch_size: 1000, batch_processed: 1, total_batches: 1 }

Rails -- { event: "data_migration_finish", migration: "BackfillPurposeForNotifyLogEntries", duration_minutes: 0, total_records: 10, records_updated: 10 }

Data replication test results

It took 51 minutes to complete the data migration.