feat: add metrics support to mock server (#606)

* feat: add metrics support to mock server

* add unit tests

* fix the unit testing

---------

Co-authored-by: rick <LinuxSuRen@users.noreply.github.com>

cmd/convert_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2023 API Testing Authors.
+Copyright 2023-2025 API Testing Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import (
 	"io"
 	"os"
 	"path"
+	"strconv"
 	"testing"
 	"time"
 
@@ -36,7 +37,8 @@ func TestConvert(t *testing.T) {
 	c.SetOut(io.Discard)
 
 	t.Run("normal", func(t *testing.T) {
-		tmpFile := path.Join(os.TempDir(), time.Now().String())
+		now := strconv.Itoa(int(time.Now().Unix()))
+		tmpFile := path.Join(os.TempDir(), now)
 		defer os.RemoveAll(tmpFile)
 
 		c.SetArgs([]string{"convert", "-p=testdata/simple-suite.yaml", "--converter=jmeter", "--target", tmpFile})

cmd/extension_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cmd
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"os"
@@ -37,7 +38,7 @@ func TestExtensionCmd(t *testing.T) {
 
 	t.Run("normal", func(t *testing.T) {
 		d := downloader.NewStoreDownloader()
-		server := mock.NewInMemoryServer(0)
+		server := mock.NewInMemoryServer(context.Background(), 0)
 
 		err := server.Start(mock.NewLocalFileReader("../pkg/downloader/testdata/registry.yaml"), "/v2")
 		assert.NoError(t, err)

cmd/mock.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 API Testing Authors.
+Copyright 2024-2025 API Testing Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -28,8 +28,9 @@ import (
 )
 
 type mockOption struct {
-	port   int
-	prefix string
+	port    int
+	prefix  string
+	metrics bool
 }
 
 func createMockCmd() (c *cobra.Command) {
@@ -45,12 +46,16 @@ func createMockCmd() (c *cobra.Command) {
 	flags := c.Flags()
 	flags.IntVarP(&opt.port, "port", "", 6060, "The mock server port")
 	flags.StringVarP(&opt.prefix, "prefix", "", "/mock", "The mock server API prefix")
+	flags.BoolVarP(&opt.metrics, "metrics", "m", true, "Enable request metrics collection")
 	return
 }
 
 func (o *mockOption) runE(c *cobra.Command, args []string) (err error) {
 	reader := mock.NewLocalFileReader(args[0])
-	server := mock.NewInMemoryServer(o.port)
+	server := mock.NewInMemoryServer(c.Context(), o.port)
+	if o.metrics {
+		server.EnableMetrics()
+	}
 	if err = server.Start(reader, o.prefix); err != nil {
 		return
 	}
@@ -58,6 +63,9 @@ func (o *mockOption) runE(c *cobra.Command, args []string) (err error) {
 	clean := make(chan os.Signal, 1)
 	signal.Notify(clean, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGQUIT)
 	printLocalIPs(c, o.port)
+	if o.metrics {
+		c.Printf("Metrics available at http://localhost:%d%s/metrics\n", o.port, o.prefix)
+	}
 
 	select {
 	case <-c.Context().Done():

cmd/server.go

@@ -275,7 +275,7 @@ func (o *serverOption) runE(cmd *cobra.Command, args []string) (err error) {
 		mockWriter = mock.NewInMemoryReader("")
 	}
 
-	dynamicMockServer := mock.NewInMemoryServer(0)
+	dynamicMockServer := mock.NewInMemoryServer(cmd.Context(), 0)
 	mockServerController := server.NewMockServerController(mockWriter, dynamicMockServer, o.httpPort)
 
 	clean := make(chan os.Signal, 1)

cmd/server_test.go

@@ -210,7 +210,7 @@ func TestFrontEndHandlerWithLocation(t *testing.T) {
 		resp := newFakeResponseWriter()
 
 		opt.getAtestBinary(resp, req, map[string]string{})
-		assert.Equal(t, `failed to read "atest": open : no such file or directory`, resp.GetBody().String())
+		assert.Contains(t, resp.GetBody().String(), `failed to read "atest"`)
 	})
 }
 

pkg/downloader/oci_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 API Testing Authors.
+Copyright 2024-2025 API Testing Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ limitations under the License.
 package downloader
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"os"
@@ -58,7 +59,7 @@ func TestDetectAuthURL(t *testing.T) {
 }
 
 func TestDownload(t *testing.T) {
-	server := mock.NewInMemoryServer(0)
+	server := mock.NewInMemoryServer(context.Background(), 0)
 	err := server.Start(mock.NewLocalFileReader("testdata/registry.yaml"), "/v2")
 	assert.NoError(t, err)
 	defer func() {

pkg/mock/in_memory.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 API Testing Authors.
+Copyright 2024-2025 API Testing Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -53,15 +53,17 @@ type inMemoryServer struct {
 	ctx        context.Context
 	cancelFunc context.CancelFunc
 	reader     Reader
+	metrics    RequestMetrics
 }
 
-func NewInMemoryServer(port int) DynamicServer {
-	ctx, cancel := context.WithCancel(context.TODO())
+func NewInMemoryServer(ctx context.Context, port int) DynamicServer {
+	ctx, cancel := context.WithCancel(ctx)
 	return &inMemoryServer{
 		port:       port,
 		wg:         sync.WaitGroup{},
 		ctx:        ctx,
 		cancelFunc: cancel,
+		metrics:    NewNoopMetrics(),
 	}
 }
 
@@ -72,6 +74,7 @@ func (s *inMemoryServer) SetupHandler(reader Reader, prefix string) (handler htt
 	s.mux = mux.NewRouter().PathPrefix(prefix).Subrouter()
 	s.prefix = prefix
 	handler = s.mux
+	s.metrics.AddMetricsHandler(s.mux)
 	err = s.Load()
 	return
 }
@@ -107,22 +110,31 @@ func (s *inMemoryServer) Load() (err error) {
 		memLogger.Info("start to proxy", "target", proxy.Target)
 		s.mux.HandleFunc(proxy.Path, func(w http.ResponseWriter, req *http.Request) {
 			api := fmt.Sprintf("%s/%s", proxy.Target, strings.TrimPrefix(req.URL.Path, s.prefix))
+			api, err = render.Render("proxy api", api, s)
+			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
+				memLogger.Error(err, "failed to render proxy api")
+				return
+			}
 			memLogger.Info("redirect to", "target", api)
 
 			targetReq, err := http.NewRequestWithContext(req.Context(), req.Method, api, req.Body)
 			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
 				memLogger.Error(err, "failed to create proxy request")
 				return
 			}
 
 			resp, err := http.DefaultClient.Do(targetReq)
 			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
 				memLogger.Error(err, "failed to do proxy request")
 				return
 			}
 
 			data, err := io.ReadAll(resp.Body)
 			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
 				memLogger.Error(err, "failed to read response body")
 				return
 			}
@@ -148,10 +160,15 @@ func (s *inMemoryServer) Start(reader Reader, prefix string) (err error) {
 	return
 }
 
+func (s *inMemoryServer) EnableMetrics() {
+	s.metrics = NewInMemoryMetrics()
+}
+
 func (s *inMemoryServer) startObject(obj Object) {
 	// create a simple CRUD server
 	s.mux.HandleFunc("/"+obj.Name, func(w http.ResponseWriter, req *http.Request) {
 		fmt.Println("mock server received request", req.URL.Path)
+		s.metrics.RecordRequest(req.URL.Path)
 		method := req.Method
 		w.Header().Set(util.ContentType, util.JSON)
 
@@ -210,6 +227,7 @@ func (s *inMemoryServer) startObject(obj Object) {
 
 	// handle a single object
 	s.mux.HandleFunc(fmt.Sprintf("/%s/{name}", obj.Name), func(w http.ResponseWriter, req *http.Request) {
+		s.metrics.RecordRequest(req.URL.Path)
 		w.Header().Set(util.ContentType, util.JSON)
 		objects := s.data[obj.Name]
 		if objects != nil {
@@ -278,15 +296,17 @@ func (s *inMemoryServer) startItem(item Item) {
 		headerSlices = append(headerSlices, k, v)
 	}
 
-	adHandler := &advanceHandler{item: &item}
+	adHandler := &advanceHandler{item: &item, metrics: s.metrics}
 	s.mux.HandleFunc(item.Request.Path, adHandler.handle).Methods(strings.Split(method, ",")...).Headers(headerSlices...)
 }
 
 type advanceHandler struct {
-	item *Item
+	item    *Item
+	metrics RequestMetrics
 }
 
 func (h *advanceHandler) handle(w http.ResponseWriter, req *http.Request) {
+	h.metrics.RecordRequest(req.URL.Path)
 	memLogger.Info("receiving mock request", "name", h.item.Name, "method", req.Method, "path", req.URL.Path,
 		"encoder", h.item.Response.Encoder)
 

pkg/mock/in_memory_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 API Testing Authors.
+Copyright 2024-2025 API Testing Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ package mock
 
 import (
 	"bytes"
+	"context"
 	"io"
 	"net/http"
 	"strings"
@@ -27,7 +28,8 @@ import (
 )
 
 func TestInMemoryServer(t *testing.T) {
-	server := NewInMemoryServer(0)
+	server := NewInMemoryServer(context.Background(), 0)
+	server.EnableMetrics()
 
 	err := server.Start(NewLocalFileReader("testdata/api.yaml"), "/mock")
 	assert.NoError(t, err)
@@ -165,13 +167,13 @@ func TestInMemoryServer(t *testing.T) {
 	})
 
 	t.Run("not found config file", func(t *testing.T) {
-		server := NewInMemoryServer(0)
+		server := NewInMemoryServer(context.Background(), 0)
 		err := server.Start(NewLocalFileReader("fake"), "/")
 		assert.Error(t, err)
 	})
 
 	t.Run("invalid webhook", func(t *testing.T) {
-		server := NewInMemoryServer(0)
+		server := NewInMemoryServer(context.Background(), 0)
 		err := server.Start(NewInMemoryReader(`webhooks:
   - timer: aa
     name: fake`), "/")
@@ -179,14 +181,14 @@ func TestInMemoryServer(t *testing.T) {
 	})
 
 	t.Run("missing name or timer in webhook", func(t *testing.T) {
-		server := NewInMemoryServer(0)
+		server := NewInMemoryServer(context.Background(), 0)
 		err := server.Start(NewInMemoryReader(`webhooks:
   - timer: 1s`), "/")
 		assert.Error(t, err)
 	})
 
 	t.Run("invalid webhook payload", func(t *testing.T) {
-		server := NewInMemoryServer(0)
+		server := NewInMemoryServer(context.Background(), 0)
 		err := server.Start(NewInMemoryReader(`webhooks:
   - name: invalid
     timer: 1ms
@@ -196,7 +198,7 @@ func TestInMemoryServer(t *testing.T) {
 	})
 
 	t.Run("invalid webhook api template", func(t *testing.T) {
-		server := NewInMemoryServer(0)
+		server := NewInMemoryServer(context.Background(), 0)
 		err := server.Start(NewInMemoryReader(`webhooks:
   - name: invalid
     timer: 1ms
@@ -205,4 +207,20 @@ func TestInMemoryServer(t *testing.T) {
       path: "{{.fake"`), "/")
 		assert.NoError(t, err)
 	})
+
+	t.Run("proxy", func(t *testing.T) {
+		resp, err = http.Get(api + "/v1/myProjects")
+		assert.NoError(t, err)
+		assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+		resp, err = http.Get(api + "/v1/invalid-template")
+		assert.NoError(t, err)
+		assert.Equal(t, http.StatusInternalServerError, resp.StatusCode)
+	})
+
+	t.Run("metrics", func(t *testing.T) {
+		resp, err = http.Get(api + "/metrics")
+		assert.NoError(t, err)
+		assert.Equal(t, http.StatusOK, resp.StatusCode)
+	})
 }

pkg/mock/metrics.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2025 API Testing Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package mock
+
+import (
+	"encoding/json"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+var _ RequestMetrics = &NoopMetrics{}
+
+// NoopMetrics implements RequestMetrics but does nothing
+type NoopMetrics struct{}
+
+// NewNoopMetrics creates a new NoopMetrics instance
+func NewNoopMetrics() *NoopMetrics {
+	return &NoopMetrics{}
+}
+
+// RecordRequest implements RequestMetrics but does nothing
+func (m *NoopMetrics) RecordRequest(path string) {}
+
+// GetMetrics implements RequestMetrics but returns empty map
+func (m *NoopMetrics) GetMetrics() MetricData {
+	return MetricData{}
+}
+
+// AddMetricsHandler implements RequestMetrics but does nothing
+func (m *NoopMetrics) AddMetricsHandler(mux MetricsHandler) {}
+
+type MetricsHandler interface {
+	HandleFunc(path string, f func(http.ResponseWriter, *http.Request)) *mux.Route
+}
+
+type MetricData struct {
+	FirstRequestTime time.Time
+	LastRequestTime  time.Time
+	Requests         map[string]int
+}
+
+// RequestMetrics represents an interface for collecting request metrics
+type RequestMetrics interface {
+	RecordRequest(path string)
+	GetMetrics() MetricData
+	AddMetricsHandler(MetricsHandler)
+}
+
+var _ RequestMetrics = &InMemoryMetrics{}
+
+// InMemoryMetrics implements RequestMetrics with in-memory storage
+type InMemoryMetrics struct {
+	MetricData
+	mu sync.RWMutex
+}
+
+// NewInMemoryMetrics creates a new InMemoryMetrics instance
+func NewInMemoryMetrics() *InMemoryMetrics {
+	return &InMemoryMetrics{
+		MetricData: MetricData{
+			Requests: make(map[string]int),
+		},
+	}
+}
+
+// RecordRequest records a request for the given path
+func (m *InMemoryMetrics) RecordRequest(path string) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.Requests[path]++
+	if m.FirstRequestTime.IsZero() {
+		m.FirstRequestTime = time.Now()
+	}
+	m.LastRequestTime = time.Now()
+}
+
+// GetMetrics returns a copy of the current metrics
+func (m *InMemoryMetrics) GetMetrics() MetricData {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.MetricData
+}
+
+func (m *InMemoryMetrics) AddMetricsHandler(mux MetricsHandler) {
+	// Add metrics endpoint
+	mux.HandleFunc("/metrics", func(w http.ResponseWriter, r *http.Request) {
+		metrics := m.GetMetrics()
+		_ = json.NewEncoder(w).Encode(metrics)
+	})
+}

pkg/mock/server.go

@@ -15,7 +15,9 @@ limitations under the License.
 */
 package mock
 
-import "net/http"
+import (
+	"net/http"
+)
 
 type Loadable interface {
 	Load() error
@@ -26,6 +28,7 @@ type DynamicServer interface {
 	SetupHandler(reader Reader, prefix string) (http.Handler, error)
 	Stop() error
 	GetPort() string
+	EnableMetrics()
 	Loadable
 }
 

pkg/mock/testdata/api.yaml

@@ -49,6 +49,11 @@ items:
             "status": "success"
           }]
         }
+proxies:
+  - path: /v1/myProjects
+    target: http://localhost:{{.GetPort}}
+  - path: /v1/invalid-template
+    target: http://localhost:{{.GetPort}
 webhooks:
   - timer: 1ms
     name: baidu

pkg/server/remote_server.go

@@ -1274,7 +1274,7 @@ func (s *mockServerController) Reload(ctx context.Context, in *MockConfig) (repl
 			}
 		}
 
-		server := mock.NewInMemoryServer(int(in.GetPort()))
+		server := mock.NewInMemoryServer(ctx, int(in.GetPort()))
 		server.Start(s.mockWriter, in.Prefix)
 		s.loader = server
 	}