Publish ITWorx Pulse source

internal/metricsapi/handler.go

@@ -0,0 +1,33 @@
+package metricsapi
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/itworx/pulse/internal/auth"
+	"github.com/itworx/pulse/internal/metriccatalog"
+	"github.com/itworx/pulse/internal/problem"
+)
+
+type Handler struct{ Registry metriccatalog.Registry }
+
+func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet || r.URL.Path != "/api/v1/metrics/catalog" {
+		http.NotFound(w, r)
+		return
+	}
+	if _, ok := auth.PrincipalFromContext(r.Context()); !ok {
+		problem.Write(w, r, http.StatusUnauthorized, "UNAUTHORIZED", "Authentication required", "Authentication is required to read the metric catalog.", nil)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Cache-Control", "private, max-age=60")
+	w.Header().Set("ETag", `"`+h.Registry.Version()+`"`)
+	if r.Header.Get("If-None-Match") == `"`+h.Registry.Version()+`"` {
+		w.WriteHeader(http.StatusNotModified)
+		return
+	}
+	if err := json.NewEncoder(w).Encode(h.Registry.Response()); err != nil {
+		return
+	}
+}

internal/metricsapi/handler_test.go

@@ -0,0 +1,52 @@
+package metricsapi
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/itworx/pulse/internal/auth"
+	"github.com/itworx/pulse/internal/metriccatalog"
+)
+
+func TestCatalogRequiresAuthentication(t *testing.T) {
+	registry, err := metriccatalog.DefaultRegistry()
+	if err != nil {
+		t.Fatal(err)
+	}
+	response := httptest.NewRecorder()
+	request := httptest.NewRequest(http.MethodGet, "/api/v1/metrics/catalog", nil)
+	Handler{Registry: registry}.ServeHTTP(response, request)
+	if response.Code != http.StatusUnauthorized {
+		t.Fatalf("status=%d body=%s", response.Code, response.Body.String())
+	}
+}
+
+func TestCatalogReturnsVersionedBindingsAndSupportsETag(t *testing.T) {
+	registry, err := metriccatalog.DefaultRegistry()
+	if err != nil {
+		t.Fatal(err)
+	}
+	handler := Handler{Registry: registry}
+	request := httptest.NewRequest(http.MethodGet, "/api/v1/metrics/catalog", nil).WithContext(auth.WithPrincipal(context.Background(), auth.Principal{Subject: "viewer", Role: auth.RoleViewer}))
+	response := httptest.NewRecorder()
+	handler.ServeHTTP(response, request)
+	if response.Code != http.StatusOK {
+		t.Fatalf("status=%d body=%s", response.Code, response.Body.String())
+	}
+	if response.Header().Get("ETag") == "" {
+		t.Fatal("missing ETag")
+	}
+	if len(response.Body.Bytes()) == 0 {
+		t.Fatal("empty catalog")
+	}
+	etag := response.Header().Get("ETag")
+	request = httptest.NewRequest(http.MethodGet, "/api/v1/metrics/catalog", nil).WithContext(auth.WithPrincipal(context.Background(), auth.Principal{Subject: "viewer", Role: auth.RoleViewer}))
+	request.Header.Set("If-None-Match", etag)
+	response = httptest.NewRecorder()
+	handler.ServeHTTP(response, request)
+	if response.Code != http.StatusNotModified {
+		t.Fatalf("etag status=%d", response.Code)
+	}
+}