[Metrics] Fix issue with collecting REST Metrics

engine/access/rest/middleware/metrics.go

@@ -11,12 +11,17 @@ import (
 	"github.com/onflow/flow-go/module"
 )
 
-func MetricsMiddleware(restCollector module.RestMetrics) mux.MiddlewareFunc {
+func MetricsMiddleware(restCollector module.RestMetrics, urlToRoute func(string) (string, error)) mux.MiddlewareFunc {
 	metricsMiddleware := middleware.New(middleware.Config{Recorder: restCollector})
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+			routeName, err := urlToRoute(req.URL.Path)
+			if err != nil {
+				return
+			}
+
 			// This is a custom metric being called on every http request
-			restCollector.AddTotalRequests(req.Context(), req.Method, req.URL.Path)
+			restCollector.AddTotalRequests(req.Context(), req.Method, routeName)
 
 			// Modify the writer
 			respWriter := &responseWriter{w, http.StatusOK}

engine/access/rest/router.go

@@ -1,7 +1,10 @@
 package rest
 
 import (
+	"fmt"
 	"net/http"
+	"regexp"
+	"strings"
 
 	"github.com/gorilla/mux"
 	"github.com/rs/zerolog"
@@ -21,7 +24,7 @@ func newRouter(backend access.API, logger zerolog.Logger, chain flow.Chain, rest
 	v1SubRouter.Use(middleware.LoggingMiddleware(logger))
 	v1SubRouter.Use(middleware.QueryExpandable())
 	v1SubRouter.Use(middleware.QuerySelect())
-	v1SubRouter.Use(middleware.MetricsMiddleware(restCollector))
+	v1SubRouter.Use(middleware.MetricsMiddleware(restCollector, URLToRoute))
 
 	linkGenerator := models.NewLinkGeneratorImpl(v1SubRouter)
 
@@ -114,3 +117,59 @@ var Routes = []route{{
 	Name:    "getNodeVersionInfo",
 	Handler: GetNodeVersionInfo,
 }}
+
+var routeUrlMap = map[string]string{}
+var routeRE = regexp.MustCompile(`(?i)/v1/(\w+)(/(\w+)(/(\w+))?)?`)
+
+func init() {
+	for _, r := range Routes {
+		routeUrlMap[r.Pattern] = r.Name
+	}
+}
+
+func URLToRoute(url string) (string, error) {
+	normalized, err := normalizeURL(url)
+	if err != nil {
+		return "", err
+	}
+
+	name, ok := routeUrlMap[normalized]
+	if !ok {
+		return "", fmt.Errorf("invalid url")
+	}
+	return name, nil
+}
+
+func normalizeURL(url string) (string, error) {
+	matches := routeRE.FindAllStringSubmatch(url, -1)
+	if len(matches) != 1 || len(matches[0]) != 6 {
+		return "", fmt.Errorf("invalid url")
+	}
+
+	// given a URL like
+	//      /v1/blocks/1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef/payload
+	// groups  [  1  ] [                                3                             ] [  5  ]
+	// normalized form like /v1/blocks/{id}/payload
+
+	parts := []string{matches[0][1]}
+
+	switch len(matches[0][3]) {
+	case 0:
+		// top level resource. e.g. /v1/blocks
+	case 64:
+		// id based resource. e.g. /v1/blocks/1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
+		parts = append(parts, "{id}")
+	case 16:
+		// address based resource. e.g. /v1/accounts/1234567890abcdef
+		parts = append(parts, "{address}")
+	default:
+		// named resource. e.g. /v1/network/parameters
+		parts = append(parts, matches[0][3])
+	}
+
+	if matches[0][5] != "" {
+		parts = append(parts, matches[0][5])
+	}
+
+	return "/" + strings.Join(parts, "/"), nil
+}

engine/access/rest/router_test.go

@@ -0,0 +1,185 @@
+package rest
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		url      string
+		expected string
+	}{
+		{
+			name:     "/v1/transactions",
+			url:      "/v1/transactions",
+			expected: "createTransaction",
+		},
+		{
+			name:     "/v1/transactions/{id}",
+			url:      "/v1/transactions/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getTransactionByID",
+		},
+		{
+			name:     "/v1/transaction_results/{id}",
+			url:      "/v1/transaction_results/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getTransactionResultByID",
+		},
+		{
+			name:     "/v1/blocks",
+			url:      "/v1/blocks",
+			expected: "getBlocksByHeight",
+		},
+		{
+			name:     "/v1/blocks/{id}",
+			url:      "/v1/blocks/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getBlocksByIDs",
+		},
+		{
+			name:     "/v1/blocks/{id}/payload",
+			url:      "/v1/blocks/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76/payload",
+			expected: "getBlockPayloadByID",
+		},
+		{
+			name:     "/v1/execution_results/{id}",
+			url:      "/v1/execution_results/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getExecutionResultByID",
+		},
+		{
+			name:     "/v1/execution_results",
+			url:      "/v1/execution_results",
+			expected: "getExecutionResultByBlockID",
+		},
+		{
+			name:     "/v1/collections/{id}",
+			url:      "/v1/collections/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getCollectionByID",
+		},
+		{
+			name:     "/v1/scripts",
+			url:      "/v1/scripts",
+			expected: "executeScript",
+		},
+		{
+			name:     "/v1/accounts/{address}",
+			url:      "/v1/accounts/6a587be304c1224c",
+			expected: "getAccount",
+		},
+		{
+			name:     "/v1/events",
+			url:      "/v1/events",
+			expected: "getEvents",
+		},
+		{
+			name:     "/v1/network/parameters",
+			url:      "/v1/network/parameters",
+			expected: "getNetworkParameters",
+		},
+		{
+			name:     "/v1/node_version_info",
+			url:      "/v1/node_version_info",
+			expected: "getNodeVersionInfo",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := URLToRoute(tt.url)
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+func TestBenchmarkParseURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		url      string
+		expected string
+	}{
+		{
+			name:     "/v1/transactions",
+			url:      "/v1/transactions",
+			expected: "createTransaction",
+		},
+		{
+			name:     "/v1/transactions/{id}",
+			url:      "/v1/transactions/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getTransactionByID",
+		},
+		{
+			name:     "/v1/transaction_results/{id}",
+			url:      "/v1/transaction_results/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getTransactionResultByID",
+		},
+		{
+			name:     "/v1/blocks",
+			url:      "/v1/blocks",
+			expected: "getBlocksByHeight",
+		},
+		{
+			name:     "/v1/blocks/{id}",
+			url:      "/v1/blocks/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getBlocksByIDs",
+		},
+		{
+			name:     "/v1/blocks/{id}/payload",
+			url:      "/v1/blocks/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76/payload",
+			expected: "getBlockPayloadByID",
+		},
+		{
+			name:     "/v1/execution_results/{id}",
+			url:      "/v1/execution_results/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getExecutionResultByID",
+		},
+		{
+			name:     "/v1/execution_results",
+			url:      "/v1/execution_results",
+			expected: "getExecutionResultByBlockID",
+		},
+		{
+			name:     "/v1/collections/{id}",
+			url:      "/v1/collections/53730d3f3d2d2f46cb910b16db817d3a62adaaa72fdb3a92ee373c37c5b55a76",
+			expected: "getCollectionByID",
+		},
+		{
+			name:     "/v1/scripts",
+			url:      "/v1/scripts",
+			expected: "executeScript",
+		},
+		{
+			name:     "/v1/accounts/{address}",
+			url:      "/v1/accounts/6a587be304c1224c",
+			expected: "getAccount",
+		},
+		{
+			name:     "/v1/events",
+			url:      "/v1/events",
+			expected: "getEvents",
+		},
+		{
+			name:     "/v1/network/parameters",
+			url:      "/v1/network/parameters",
+			expected: "getNetworkParameters",
+		},
+		{
+			name:     "/v1/node_version_info",
+			url:      "/v1/node_version_info",
+			expected: "getNodeVersionInfo",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			start := time.Now()
+			for i := 0; i < 100_000; i++ {
+				_, _ = URLToRoute(tt.url)
+			}
+			t.Logf("%s: %v", tt.name, time.Since(start)/100_000)
+		})
+	}
+}

module/metrics.go

@@ -610,7 +610,7 @@ type RestMetrics interface {
 	// Example recorder taken from:
 	// https://github.com/slok/go-http-metrics/blob/master/metrics/prometheus/prometheus.go
 	httpmetrics.Recorder
-	AddTotalRequests(ctx context.Context, service string, id string)
+	AddTotalRequests(ctx context.Context, method string, routeName string)
 }
 
 type GRPCConnectionPoolMetrics interface {

module/metrics/rest_api.go

@@ -81,7 +81,7 @@ func NewRestCollector(cfg metricsProm.Config) module.RestMetrics {
 			Subsystem: "http",
 			Name:      "requests_total",
 			Help:      "The number of requests handled over time.",
-		}, []string{cfg.ServiceLabel, cfg.HandlerIDLabel}),
+		}, []string{cfg.MethodLabel, cfg.HandlerIDLabel}),
 	}
 
 	cfg.Registry.MustRegister(
@@ -108,6 +108,6 @@ func (r *RestCollector) AddInflightRequests(_ context.Context, p httpmetrics.HTT
 }
 
 // New custom method to track all requests made for every REST API request
-func (r *RestCollector) AddTotalRequests(_ context.Context, method string, id string) {
-	r.httpRequestsTotal.WithLabelValues(method, id).Inc()
+func (r *RestCollector) AddTotalRequests(_ context.Context, method string, routeName string) {
+	r.httpRequestsTotal.WithLabelValues(method, routeName).Inc()
 }