add support for s3 bucket metrics (#13)

README.md

@@ -16,6 +16,7 @@ GET /v1/cost/{account}/instances/{id}/metrics/graph?metric={metric1}[&metric={me
 
 GET /v1/metrics/{account}/instances/{id}/graph?metric={metric1}[&metric={metric2}&start=-P1D&end=PT0H&period=300]
 GET /v1/metrics/{account}/clusters/{cluster}/services/{service}/graph?metric={metric1}[&metric={metric2}&start=-P1D&end=PT0H&period=300]
+GET /v1/metrics/{account}/buckets/{bucket}/graph?metric={BucketSizeBytes|NumberOfObjects}
 ```
 
 ## Usage

api/handlers_metrics.go

@@ -206,3 +206,86 @@ func parseQuery(r *http.Request, request cloudwatch.MetricsRequest) error {
 
 	return nil
 }
+
+// GetS3MetricsURLHandler gets metrics from cloudwatch and returns a link to the image
+func (s *server) GetS3MetricsURLHandler(w http.ResponseWriter, r *http.Request) {
+	w = LogWriter{w}
+	vars := mux.Vars(r)
+	account := vars["account"]
+	bucketName := vars["bucket"]
+	metric := vars["metric"]
+
+	cwService, ok := s.cloudwatchServices[account]
+	if !ok {
+		msg := fmt.Sprintf("cloudwatch service not found for account: %s", account)
+		handleError(w, apierror.New(apierror.ErrNotFound, msg, nil))
+		return
+	}
+	log.Debugf("found cloudwatch service %+v", cwService)
+
+	resultCache, ok := s.resultCache[account]
+	if !ok {
+		msg := fmt.Sprintf("result cache not found for account: %s", account)
+		handleError(w, apierror.New(apierror.ErrNotFound, msg, nil))
+		return
+	}
+	log.Debugf("found cost explorer result cache %+v", *resultCache)
+
+	// only support NumberOfObjects and BucketSizeBytes
+	var storageType string
+	switch metric {
+	case "BucketSizeBytes":
+		storageType = "StandardStorage"
+	case "NumberOfObjects":
+		storageType = "AllStorageTypes"
+	default:
+		msg := fmt.Sprintf("invalid metric requested: %s", metric)
+		handleError(w, apierror.New(apierror.ErrBadRequest, msg, nil))
+		return
+	}
+
+	req := cloudwatch.MetricsRequest{
+		"period": int64(86400),
+		"stat":   "Maximum",
+		"start":  "-P30D",
+		"end":    "PT0H",
+		"metrics": []cloudwatch.Metric{
+			{"AWS/S3", metric, "StorageType", storageType, "BucketName", bucketName},
+		},
+	}
+
+	key := fmt.Sprintf("%s/%s/%s/%v/%v/%v", Org, bucketName, metric, req["start"], req["end"], req["period"])
+	hashedCacheKey := s.imageCache.HashedKey(key)
+	if res, expire, ok := resultCache.GetWithExpiration(hashedCacheKey); ok {
+		log.Debugf("found cached object: %s", res)
+
+		if body, ok := res.([]byte); ok {
+			w.Header().Set("X-Cache-Hit", "true")
+			w.Header().Set("X-Cache-Expire", fmt.Sprintf("%0.fs", time.Until(expire).Seconds()))
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			w.Write(body)
+			return
+		}
+	}
+
+	log.Debugf("getting metrics with request %+v", req)
+	image, err := cwService.GetMetricWidget(r.Context(), req)
+	if err != nil {
+		log.Errorf("failed getting metrics widget image: %s", err)
+		handleError(w, err)
+		return
+	}
+
+	meta, err := s.imageCache.Save(r.Context(), hashedCacheKey, image)
+	if err != nil {
+		log.Errorf("failed saving metrics widget image to cache: %s", err)
+		handleError(w, err)
+		return
+	}
+	resultCache.Set(hashedCacheKey, meta, 300*time.Second)
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	w.Write(meta)
+}

api/routes.go

@@ -33,4 +33,6 @@ func (s *server) routes() {
 	metricsApi.HandleFunc("/{account}/instances/{id}/graph", s.GetEC2MetricsURLHandler).Methods(http.MethodGet)
 	// metrics endpoints for ECS services
 	metricsApi.HandleFunc("/{account}/clusters/{cluster}/services/{service}/graph", s.GetECSMetricsURLHandler).Methods(http.MethodGet)
+	// metrics endpoints for S3 buckets
+	metricsApi.HandleFunc("/{account}/buckets/{bucket}/graph", s.GetS3MetricsURLHandler).Queries("metric", "{metric:(?:BucketSizeBytes|NumberOfObjects)}").Methods(http.MethodGet)
 }