Micronaut - MongoDB migrations (Mongock)

Apply Mongock migration guidelines for Micronaut and Micronaut Data MongoDB.

What is covered in this Skill?

• Mongock runner/driver selection for Micronaut projects
• Micronaut bean wiring for MongoDB client access and controlled migration execution
• Code-first @ChangeUnit migrations with @Execution and rollback hooks
• Locking, idempotency, transaction limits, and startup/runtime trade-offs
• Integration tests with @MicronautTest and Testcontainers MongoDB
• Coordination with @515-frameworks-micronaut-mongodb

Scope: Apply recommendations based on the reference rules and good/bad examples.

Constraints

Compile before Mongock or MongoDB migration changes; verify after changes.

• MANDATORY: Run ./mvnw compile or mvn compile before applying any change
• SAFETY: If compilation fails, stop immediately
• VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
• BEFORE APPLYING: Read the reference for detailed rules and good/bad patterns
• EDGE CASE: If a Micronaut-specific Mongock runner is unavailable or incompatible, use an explicit standalone runner bean/job and document that trade-off

When to use this skill

• Add Mongock migrations in Micronaut
• Review Micronaut MongoDB data migrations
• Configure Mongock change units with Micronaut Data MongoDB
• Create Mongock change units for Micronaut MongoDB
• Review Mongock migration ordering in a Micronaut service

Workflow

1. Read references and inspect MongoDB setup

Read references/516-frameworks-micronaut-mongodb-migrations-mongock.md, references/516-frameworks-micronaut-mongodb-migrations-mongock-antipatterns.md, and references/516-frameworks-micronaut-mongodb-migrations-mongock-parallel-change.md, then inspect pom.xml, Micronaut MongoDB configuration, and existing @515-frameworks-micronaut-mongodb persistence patterns.

2. Choose runner, driver, and execution policy

Select compatible Mongock coordinates, wire the runner through Micronaut beans, configure migration scan packages, and decide startup vs controlled-job execution.

3. Apply framework-aligned migrations

Implement/refactor @ChangeUnit classes with idempotent operations, explicit ordering, rollback hooks, and safe lock/transaction settings.

4. Run verification and report results

Execute build/tests, including @MicronautTest with Testcontainers MongoDB where feasible, and summarize outcomes and follow-up risks.

Reference

For detailed guidance, examples, and constraints, see:

• references/516-frameworks-micronaut-mongodb-migrations-mongock.md
• references/516-frameworks-micronaut-mongodb-migrations-mongock-antipatterns.md
• references/516-frameworks-micronaut-mongodb-migrations-mongock-parallel-change.md