Replace the positional-placeholder SQL in the repositories with the
Masterminds/squirrel builder, so column lists and $N numbering are no
longer maintained by hand. The optimistic-lock guard on task Update is now
a readable Where(id, version-1) instead of a $13-1 expression.
Two genuinely set-based statements stay as raw SQL on purpose — claimNext
(a FOR UPDATE SKIP LOCKED CTE) and expireLeases (CASE logic in the SET) —
because a builder cannot express them more clearly.
Align the coordinator with the master PLAN.md (CTX-00, CTX-04) and harden
process startup.
- CTX-00: freeze docs/api-contract.md as the v1 source of truth for the
Go coordinator and Python worker.
- CTX-04: worker registry — workers table (migration 0002), domain.Worker,
RegisterWorker use case, WorkerRepository, and POST /workers/register.
- Contract alignment: claim uses `capabilities` (was `workloads`),
COORDINATOR_TOKEN env (WORKER_AUTH_TOKEN kept as fallback), and
GET /health now reports database readiness (503 when the DB is down).
- Logging: logs are teed to stdout and an optional rotated file (LOG_FILE)
via lumberjack, so they survive a container rebuild.
- Startup resilience: the initial DB connection is retried with backoff,
so the coordinator waits for Postgres to boot instead of crash-looping.
Adds the SciMesh coordinator: a durable task-queue server on PostgreSQL
that owns all database access, with workers reaching it over HTTP only.
Structured as a modular monolith following Clean Architecture:
domain entities and their invariants, no I/O
usecase business operations + repository/clock ports
transport HTTP handlers, DTOs, auth, error mapping
storage PostgreSQL repositories, transactions carried in context
infra config, pool, clock, server, lease reaper
Dependencies point strictly inward; domain imports nothing from the module.
Working: layer wiring, routing, shared-token auth, access logging, request
IDs, domain-error to status-code mapping, transactional boundaries,
graceful shutdown (HTTP drain -> reaper stop -> pool close), migrations,
and a Compose stack starting Postgres -> migrations -> coordinator.
The domain is complete and covered by unit tests that need no database:
lease ownership, stale attempts, idempotent result replay, retry budgets,
and lease expiry.
Repository methods are stubs returning ErrNotImplemented (HTTP 501). The
SQL for atomic claiming (FOR UPDATE SKIP LOCKED) and for lease expiry is
written and ready to wire up.
See coordinator/ARCHITECTURE.md for the layer map and a request traced
through every layer.
Efremenko Arhip