316-frameworks-spring-mongodb-migrations-mongock

# Spring - MongoDB migrations (Mongock) Apply Mongock migration guidelines for Spring Boot and Spring Data MongoDB. **What is covered in this Skill?** - Mongock BOM, Spring Boot runner, and Spring Data MongoDB driver coordinates - `mongock.migration-scan-package` configuration and startup execution - Code-first `@ChangeUnit` migrations with `@Execution` and rollback hooks - Locking, idempotency, transaction limits, and forward-only rollout discipline - Integration tests with Testcontainers MongoDB - Coordination with `@315-frameworks-spring-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 the project Spring Data MongoDB version is not compatible with the selected Mongock driver, stop and ask whether to pin/upgrade Mongock or use a lower driver generation ## When to use this skill - Add Mongock migrations in Spring Boot - Review Spring MongoDB data migrations - Configure Mongock change units for Spring Data MongoDB ## Workflow 1. **Read reference and inspect MongoDB setup** Read `references/316-frameworks-spring-mongodb-migrations-mongock.md` and inspect `pom.xml`, Spring Boot version, MongoDB configuration, and existing `@315-frameworks-spring-mongodb` persistence patterns. 2. **Choose runner, driver, and execution policy** Select Mongock coordinates compatible with the active Spring Data MongoDB generation, 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 Testcontainers-backed MongoDB migration checks where feasible, and summarize outcomes and follow-up risks. ## Reference For detailed guidance, examples, and constraints, see [references/316-frameworks-spring-mongodb-migrations-mongock.md](references/316-frameworks-spring-mongodb-migrations-mongock.md).