fix: guard destructive replication/teardown Ansible tasks against re-runs - #70
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michaelcoburn merged 1 commit intoJun 2, 2026
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The mysql2/mysql3 provisioning tasks reset replication and DROP the lab databases (imdb/world/sakila/sysbench) via raw shell, with no idempotency guard. Re-running the playbook on an already-provisioned node (the documented `--limit` re-provision flow, or a retry after a partial failure) would tear down a working replica or wipe student data. Add `creates:` sentinel guards so each runs once at initial provision and is skipped on re-runs: - Connect Async Replication -> /var/lib/mysql/.training_async_repl_done - GROUP REPLICATION drop/reset -> /var/lib/mysql/.training_gr_reset_done Scoped per discussion to guarding the destructive tasks only (not a full idempotency refactor) since the instances are ephemeral. db2's package removal is already guarded by its existing_setup stat check. Closes percona#56 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Closes #56 (scoped — see note)
The
mysql2/mysql3provisioning tasks reset replication and DROP the lab databases (imdb/world/sakila/sysbench) via rawshell, with no idempotency guard. The README tells instructors they can re-run the playbook (and the--limitflow re-provisions a single node) — but re-running these on an already-configured node would tear down a working replica or wipe student data.Change
Add
creates:sentinel guards so each runs once at initial provision and is skipped on re-runs:Connect Async Replication→/var/lib/mysql/.training_async_repl_doneGROUP REPLICATION - Drop everything…→/var/lib/mysql/.training_gr_reset_done(The marker is only written after the
mysqlcommand succeeds, so a failed run safely retries.db2's package removal is already guarded by itsexisting_setupstat check.)Scope note
Deliberately scoped to guarding the destructive tasks rather than a full idempotency refactor of
hosts.yml— the training instances are ephemeral, so the high-value win is "a re-run never wipes data," not rewriting every shell task. The broader refactor can remain a someday-maybe.Verification
ansible-lint hosts.yml roles/→Passed: 0 failure(s); YAML parses clean.