The harness brings up the SaaS tenant topology on localhost using the
SAME workspace-server/Dockerfile.tenant image that ships to production.
Tests run against http://harness-tenant.localhost:8080 and exercise the
same code path a real tenant takes:
client
→ cf-proxy (nginx; CF tunnel + LB header rewrites)
→ tenant (Dockerfile.tenant — combined platform + canvas)
→ cp-stub (minimal Go CP stand-in for /cp/* paths)
→ postgres + redis
Why this exists: bugs that survive `go run ./cmd/server` and ship to
prod almost always live in env-gated middleware (TenantGuard, /cp/*
proxy, canvas proxy), header rewrites, or the strict-auth / live-token
mode. The harness activates ALL of them locally so #2395 + #2397-class
bugs can be reproduced before deploy.
Phase 1 surface:
- cp-stub/main.go: minimal CP stand-in. /cp/auth/me, redeploy-fleet,
/__stub/{peers,mode,state} for replay scripts. Catch-all returns
501 with a clear message when a new CP route appears.
- cf-proxy/nginx.conf: rewrites Host to <slug>.localhost, injects
X-Forwarded-*, disables buffering to mirror CF tunnel streaming
semantics.
- compose.yml: one service per topology layer; tenant builds from
the actual production Dockerfile.tenant.
- up.sh / down.sh / seed.sh: lifecycle scripts.
- replays/peer-discovery-404.sh: reproduces #2397 + asserts the
diagnostic helper from PR #2399 surfaces "404" + "registered".
- replays/buildinfo-stale-image.sh: reproduces #2395 + asserts
/buildinfo wire shape + GIT_SHA injection from PR #2398.
- README.md: topology, quickstart, what the harness does NOT cover.
Phases 2-3 (separate PRs):
- Phase 2: convert tests/e2e/test_api.sh to target the harness URL
instead of localhost; make harness-based replays a required CI gate.
- Phase 3: config-coherence lint that diffs harness env list against
production CP's env list, fails CI on drift.
Verification:
- cp-stub builds (go build ./...).
- cp-stub responds to all stubbed endpoints (smoke-tested locally).
- compose.yml passes `docker compose config --quiet`.
- All shell scripts pass `bash -n` syntax check.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
