[P2] ci-cd: cancel-in-progress interrupts long provision and increases drift risk

[Cataldir]

Problem

Workflow concurrency currently uses branch-level cancel-in-progress: true, which can terminate long-running provision executions and amplify state drift/retry churn.

Type

• tech debt

Evidence

• .github/workflows/azd-deploy.yml uses:
  • concurrency.group: azd-deploy-${{ github.ref }}
  • cancel-in-progress: true
• Recent runs:
  • https://github.com/Azure-Samples/tutor/actions/runs/23126353038 (cancelled during Provision infrastructure after ~90m)
  • https://github.com/Azure-Samples/tutor/actions/runs/23125888889 (cancelled)
• Repeated cancellations overlap with ongoing provision and obstruct clean convergence.

Reproduction

1. Start a workflow_dispatch deploy on main.
2. Trigger another deploy/push on same ref before completion.
3. Observe prior in-flight run cancellation and interrupted provision.

Acceptance Criteria

• Concurrency is scoped per environment and does not cancel active provision in-flight for same env.
• New runs queue or fail-fast with explicit message instead of interrupting active infra apply.
• Workflow summary surfaces cancellation reason and superseding run id.
• Document runbook guidance for safe re-run behavior.

Suggested Owner

platform-quality

[Cataldir]

Execution assignment: platform-quality (delegated via PlatformEngineer analysis in this investigation).\n\nDependency: can start in parallel, but rollout should happen after #115 validation to avoid masking root-cause fixes.\n\nChecklist tracking status:\n- [ ] Environment-scoped concurrency group\n- [ ] No cancel-in-progress for active provision\n- [ ] Queue/clear operator signaling\n- [ ] Runbook update for rerun behavior