Prevent deploy from conflicting with in-progress pipeline runs

[retlehs]

Problem

When a deploy runs while a pipeline (wpcomposer pipeline) is in progress, there are potential race conditions:

1. The deploy restarts the web server, which is harmless on its own
2. But if the pipeline is in its build/deploy phase, both processes could call deploy.Promote and swap storage/repository/current concurrently
3. Two concurrent builds could write conflicting rows to the builds table

The pipeline binary stays in memory (Linux keeps the old inode), so it won't crash — but the results could be unpredictable.

Possible solutions

• Lock file — pipeline acquires a lock (e.g. storage/pipeline.lock) before starting; deploy task checks for it and skips the service restart or waits
• Deploy skips restart if pipeline is active — systemctl is-active wpcomposer-pipeline check in the Ansible deploy task
• Pipeline guards its own deploy step — only Promote if no other build was promoted since the pipeline started

Context

The pipeline runs on a timer via wpcomposer-pipeline.service (oneshot). Deploys are triggered manually via Ansible. Both use shared storage and the same SQLite database.

[retlehs]

No longer an issue