anchorage v1.0 initial tree

Greenfield Go multi-tenant IPFS Pinning Service wire-compatible with the
IPFS Pinning Services API spec. Paired 1:1 with Kubo over localhost RPC,
clustered via embedded NATS JetStream, Postgres source-of-truth with
RLS-enforced tenancy, Fiber + huma v2 for the HTTP surface, Authentik
OIDC for session login with kid-rotated HS256 JWT API tokens.

Feature-complete against the 22-milestone build plan, including the
ship-it v1.0 gap items:

  * admin CLIs: drain/uncordon, maintenance, mint-token, rotate-key,
    prune-denylist, rebalance --dry-run, cache-stats, cluster-presences
  * TTL leader election via NATS KV, fence tokens, JetStream dedup
  * rebalancer (plan/apply split), reconciler, requeue sweeper
  * ristretto caches with NATS-backed cross-node invalidation
    (placements live-nodes + token denylist)
  * maintenance watchdog for stuck cluster-pause flag
  * Prometheus /metrics with CIDR ACL, HTTP/pin/scheduler/cache gauges
  * rate limiting: session (10/min) + anonymous global (120/min)
  * integration tests: rebalance, refcount multi-org, RLS belt
  * goreleaser (tar + deb/rpm/apk + Alpine Docker) targeting Gitea

Stack: Cobra/Viper, Fiber v2 + huma v2, embedded NATS JetStream,
pgx/sqlc/golang-migrate, ristretto, TypeID, prometheus/client_golang,
testcontainers-go.

internal/pkg/httpserver/server.go

@@ -0,0 +1,91 @@
+// Package httpserver composes the Fiber app and its middleware stack.
+//
+// The actual route tree is registered by internal/pkg/openapi through the
+// humafiber adapter, so this package only owns lifecycle: configuration,
+// graceful start, graceful shutdown, and basic observability middleware.
+package httpserver
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/recover"
+	"github.com/gofiber/fiber/v2/middleware/requestid"
+
+	"anchorage/internal/pkg/metrics"
+)
+
+// Options configures a Server.
+type Options struct {
+	Host         string
+	Port         int
+	ReadTimeout  time.Duration
+	WriteTimeout time.Duration
+
+	// MetricsACLCIDRs is the allowlist for /metrics. Nil → use the
+	// metrics package default (loopback + RFC1918). Explicit empty
+	// slice → no restriction (firewall-only).
+	MetricsACLCIDRs []string
+}
+
+// Server wraps *fiber.App with lifecycle helpers.
+type Server struct {
+	App  *fiber.App
+	opts Options
+}
+
+// New constructs a Server with the standard anchorage middleware stack.
+//
+// The returned *fiber.App is exposed on Server.App so callers can register
+// routes before Start is called.
+func New(opts Options) *Server {
+	app := fiber.New(fiber.Config{
+		AppName:               "anchorage",
+		DisableStartupMessage: true,
+		ReadTimeout:           opts.ReadTimeout,
+		WriteTimeout:          opts.WriteTimeout,
+		ErrorHandler: func(c *fiber.Ctx, err error) error {
+			// Fiber default returns an HTML body; JSON is more useful
+			// for our API clients.
+			code := fiber.StatusInternalServerError
+			if fe, ok := err.(*fiber.Error); ok {
+				code = fe.Code
+			}
+			return c.Status(code).JSON(fiber.Map{
+				"error":   http.StatusText(code),
+				"message": err.Error(),
+			})
+		},
+	})
+
+	app.Use(recover.New())
+	app.Use(requestid.New())
+	app.Use(accessLog())
+
+	// /metrics lives at root (NOT under /v1) so Prometheus scrapers
+	// find it at the conventional path. Gated by a CIDR ACL — see
+	// metrics.ACL and MetricsConfig.AllowCIDRs.
+	if acl, err := metrics.ACL(opts.MetricsACLCIDRs); err != nil {
+		slog.Error("httpserver: bad metrics ACL; /metrics disabled", "err", err)
+	} else {
+		app.Get("/metrics", acl, metrics.Handler())
+	}
+
+	return &Server{App: app, opts: opts}
+}
+
+// Start binds and listens. Returns only on listener error.
+func (s *Server) Start(_ context.Context) error {
+	addr := fmt.Sprintf("%s:%d", s.opts.Host, s.opts.Port)
+	slog.Info("httpserver: listening", "addr", addr)
+	return s.App.Listen(addr)
+}
+
+// Shutdown drains in-flight requests with a bounded grace period.
+func (s *Server) Shutdown(ctx context.Context) error {
+	return s.App.ShutdownWithContext(ctx)
+}