feat(server): tenant-registry skeleton boots against dev stack

Minimal Go service: /healthz + /v1/tenants/by-slug/:slug + /v1/tenants/:id with an in-memory store seeded with the acme tenant. Stdlib-only; pgx + JWT validation land in M4.1 follow-up.

internal/server/server.go

@@ -0,0 +1,106 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"log/slog"
+	"net/http"
+	"time"
+
+	"gitea.meghsakha.com/platform/tenant-registry/internal/config"
+	"gitea.meghsakha.com/platform/tenant-registry/internal/store"
+)
+
+type deps struct {
+	cfg    *config.Config
+	log    *slog.Logger
+	tenant *store.Memory
+}
+
+func NewRouter(cfg *config.Config, log *slog.Logger) http.Handler {
+	d := &deps{cfg: cfg, log: log, tenant: store.NewMemory()}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", d.healthz)
+	mux.HandleFunc("GET /v1/tenants/by-slug/{slug}", d.tenantBySlug)
+	mux.HandleFunc("GET /v1/tenants/{id}", d.tenantByID)
+
+	return logRequest(log)(mux)
+}
+
+func (d *deps) healthz(w http.ResponseWriter, _ *http.Request) {
+	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
+}
+
+func (d *deps) tenantBySlug(w http.ResponseWriter, r *http.Request) {
+	slug := r.PathValue("slug")
+	ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
+	defer cancel()
+
+	t, err := d.tenant.BySlug(ctx, slug)
+	if errors.Is(err, store.ErrNotFound) {
+		writeError(w, http.StatusNotFound, "tenant_not_found", "no tenant with that slug")
+		return
+	}
+	if err != nil {
+		d.log.Error("tenant lookup failed", "err", err)
+		writeError(w, http.StatusInternalServerError, "internal", "lookup failed")
+		return
+	}
+	writeJSON(w, http.StatusOK, t)
+}
+
+func (d *deps) tenantByID(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
+	defer cancel()
+
+	t, err := d.tenant.ByID(ctx, id)
+	if errors.Is(err, store.ErrNotFound) {
+		writeError(w, http.StatusNotFound, "tenant_not_found", "no tenant with that id")
+		return
+	}
+	if err != nil {
+		d.log.Error("tenant lookup failed", "err", err)
+		writeError(w, http.StatusInternalServerError, "internal", "lookup failed")
+		return
+	}
+	writeJSON(w, http.StatusOK, t)
+}
+
+func writeJSON(w http.ResponseWriter, code int, body any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	_ = json.NewEncoder(w).Encode(body)
+}
+
+func writeError(w http.ResponseWriter, code int, kind, msg string) {
+	writeJSON(w, code, map[string]string{"error": kind, "message": msg})
+}
+
+func logRequest(log *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			ww := &statusRecorder{ResponseWriter: w, code: 200}
+			next.ServeHTTP(ww, r)
+			log.Info("http",
+				"method", r.Method,
+				"path", r.URL.Path,
+				"status", ww.code,
+				"duration_ms", time.Since(start).Milliseconds(),
+			)
+		})
+	}
+}
+
+type statusRecorder struct {
+	http.ResponseWriter
+	code int
+}
+
+func (s *statusRecorder) WriteHeader(c int) {
+	s.code = c
+	s.ResponseWriter.WriteHeader(c)
+}

internal/server/server_test.go

@@ -0,0 +1,73 @@
+package server
+
+import (
+	"encoding/json"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"gitea.meghsakha.com/platform/tenant-registry/internal/config"
+)
+
+func newTestServer(t *testing.T) *httptest.Server {
+	t.Helper()
+	cfg := &config.Config{Env: "dev", Addr: ":0"}
+	h := NewRouter(cfg, slog.New(slog.NewTextHandler(os.Stderr, nil)))
+	return httptest.NewServer(h)
+}
+
+func TestHealthz(t *testing.T) {
+	srv := newTestServer(t)
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/healthz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("got %d, want 200", resp.StatusCode)
+	}
+}
+
+func TestTenantBySlug_acme(t *testing.T) {
+	srv := newTestServer(t)
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/v1/tenants/by-slug/acme")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		t.Fatalf("got %d, want 200; body=%s", resp.StatusCode, body)
+	}
+	var payload map[string]any
+	if err := json.NewDecoder(resp.Body).Decode(&payload); err != nil {
+		t.Fatal(err)
+	}
+	if payload["slug"] != "acme" {
+		t.Fatalf("expected slug=acme, got %v", payload["slug"])
+	}
+	if payload["status"] != "active" {
+		t.Fatalf("expected status=active, got %v", payload["status"])
+	}
+}
+
+func TestTenantBySlug_unknown(t *testing.T) {
+	srv := newTestServer(t)
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/v1/tenants/by-slug/nope")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusNotFound {
+		t.Fatalf("got %d, want 404", resp.StatusCode)
+	}
+}