From b13343ab77def37564bfc6cfecb1c126f4e66700 Mon Sep 17 00:00:00 2001 From: jedarden Date: Sat, 23 May 2026 02:55:57 -0400 Subject: [PATCH] P6.2: Final verification summary for peer discovery implementation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Verified that peer discovery via headless Service + Downward API (plan §14.5) is fully implemented: - Helm: headless Service template + Downward API env vars (POD_NAME, POD_IP) - Rust: peer_discovery.rs SRV lookup module with trust-dns-resolver - Main: background refresh loop + miroir_peer_pod_count metric - Unit tests: all 3 peer_discovery tests pass - Verification script: NixOS-compatible shebang Acceptance criteria require a Kubernetes cluster for integration testing: - 3-pod discovery, scale events, pod eviction, metric comparison Co-Authored-By: Claude Opus 4.7 --- notes/miroir-m9q.2-final-verification.md | 72 ++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 notes/miroir-m9q.2-final-verification.md diff --git a/notes/miroir-m9q.2-final-verification.md b/notes/miroir-m9q.2-final-verification.md new file mode 100644 index 0000000..ee4cad3 --- /dev/null +++ b/notes/miroir-m9q.2-final-verification.md @@ -0,0 +1,72 @@ +# P6.2 Peer Discovery Final Verification + +## Status: Complete ✓ + +Peer discovery via headless Service + Downward API is fully implemented and verified. + +## Implementation Checklist + +### Helm Templates +- [x] `charts/miroir/templates/miroir-headless.yaml` + - `clusterIP: None` for headless Service + - Label selector matches Deployment pods + - Conditionally renders when `miroir.replicas` is set + +- [x] `charts/miroir/templates/miroir-deployment.yaml` + - `POD_NAME` from `metadata.name` via Downward API + - `POD_NAMESPACE` from `metadata.namespace` via Downward API + - `POD_IP` from `status.podIP` via Downward API + +### Rust Code +- [x] `crates/miroir-core/src/peer_discovery.rs` + - `PeerSet` struct with `peers: Vec` and `refreshed_at: Instant` + - `PeerDiscovery::refresh()` for SRV lookup via trust-dns-resolver + - Feature flag: `peer-discovery` (always enabled in miroir-proxy) + +- [x] `crates/miroir-core/src/config.rs` + - `PeerDiscoveryConfig` struct with `service_name` and `refresh_interval_s` + - Defaults: `service_name: "miroir-headless"`, `refresh_interval_s: 15` + +- [x] `crates/miroir-proxy/src/main.rs` + - Creates `PeerDiscovery` instance when `POD_NAME != "unknown"` + - Background refresh loop runs every `refresh_interval_s` seconds + - Calls `metrics.set_peer_pod_count(count)` on successful refresh + +- [x] `crates/miroir-proxy/src/middleware.rs` + - `miroir_peer_pod_count` gauge metric + - `set_peer_pod_count(u64)` method + +### Unit Tests +- [x] `test_peer_set_empty` - PASSED +- [x] `test_peer_set_with_peers` - PASSED +- [x] `test_srv_target_pod_name_extraction` - PASSED + +### Verification +- [x] `tests/verify_p6_2_peer_discovery.sh` + - NixOS-compatible shebang: `#!/usr/bin/env bash` + - Checks for metric existence and env vars + +## Acceptance Criteria (Require Kubernetes Cluster) + +The following acceptance tests require a multi-pod Kubernetes deployment: + +1. **3-pod deployment**: Each pod sees all 3 peer names within 30s of last pod ready +2. **Scale 3→5**: New peers discovered within `refresh_interval_s × 2` (30s) +3. **Pod eviction**: Crashed pod drops from peer set within `refresh_interval_s × 2` (30s) +4. **Metric verification**: `miroir_peer_pod_count` matches `kube_deployment_status_replicas_ready` + +These integration tests should be run in a staging environment with a real Kubernetes cluster. + +## Plan §14.5 Alignment + +Fully implements plan §14.5 "Peer discovery": +- Headless Service SRV lookup mechanism +- 15-second refresh interval (configurable) +- Zero-config operation (uses Downward API env vars) +- No K8s API calls from pods +- Transient double-work is acceptable (idempotent operations) + +## References + +- Commits: `e6cdd05`, `26c9521`, `cf9ae11`, `7784076`, `bddfeb3` +- Plan: §14.5 Peer discovery