feat: add unique ids to all HTTP requests (#3845)

coderd/httpmw/requestid.go

@@ -0,0 +1,34 @@
+package httpmw
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/google/uuid"
+
+	"cdr.dev/slog"
+)
+
+type requestIDContextKey struct{}
+
+// RequestID returns the ID of the request.
+func RequestID(r *http.Request) uuid.UUID {
+	rid, ok := r.Context().Value(requestIDContextKey{}).(uuid.UUID)
+	if !ok {
+		panic("developer error: request id middleware not provided")
+	}
+	return rid
+}
+
+// AttachRequestID adds a request ID to each HTTP request.
+func AttachRequestID(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		rid := uuid.New()
+
+		ctx := context.WithValue(r.Context(), requestIDContextKey{}, rid)
+		ctx = slog.With(ctx, slog.F("request_id", rid))
+
+		rw.Header().Set("X-Coder-Request-Id", rid.String())
+		next.ServeHTTP(rw, r.WithContext(ctx))
+	})
+}

coderd/httpmw/requestid_test.go

@@ -0,0 +1,33 @@
+package httpmw_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/stretchr/testify/require"
+
+	"github.com/coder/coder/coderd/httpmw"
+)
+
+func TestRequestID(t *testing.T) {
+	t.Parallel()
+
+	rtr := chi.NewRouter()
+	rtr.Use(httpmw.AttachRequestID)
+	rtr.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		rid := httpmw.RequestID(r)
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(rid.String()))
+	})
+	r := httptest.NewRequest("GET", "/", nil)
+	rw := httptest.NewRecorder()
+	rtr.ServeHTTP(rw, r)
+
+	res := rw.Result()
+	defer res.Body.Close()
+	require.Equal(t, http.StatusOK, res.StatusCode)
+	require.NotEmpty(t, res.Header.Get("X-Coder-Request-ID"))
+	require.NotEmpty(t, rw.Body.Bytes())
+}