Merge pull request #40081 from thaJeztah/http_constants

Use http constants for HTTP methods and status codes

api/server/httputils/form_test.go

@@ -23,7 +23,7 @@ func TestBoolValue(t *testing.T) {
 	for c, e := range cases {
 		v := url.Values{}
 		v.Set("test", c)
-		r, _ := http.NewRequest("POST", "", nil)
+		r, _ := http.NewRequest(http.MethodPost, "", nil)
 		r.Form = v
 
 		a := BoolValue(r, "test")
@@ -34,14 +34,14 @@ func TestBoolValue(t *testing.T) {
 }
 
 func TestBoolValueOrDefault(t *testing.T) {
-	r, _ := http.NewRequest("GET", "", nil)
+	r, _ := http.NewRequest(http.MethodGet, "", nil)
 	if !BoolValueOrDefault(r, "queryparam", true) {
 		t.Fatal("Expected to get true default value, got false")
 	}
 
 	v := url.Values{}
 	v.Set("param", "")
-	r, _ = http.NewRequest("GET", "", nil)
+	r, _ = http.NewRequest(http.MethodGet, "", nil)
 	r.Form = v
 	if BoolValueOrDefault(r, "param", true) {
 		t.Fatal("Expected not to get true")
@@ -59,7 +59,7 @@ func TestInt64ValueOrZero(t *testing.T) {
 	for c, e := range cases {
 		v := url.Values{}
 		v.Set("test", c)
-		r, _ := http.NewRequest("POST", "", nil)
+		r, _ := http.NewRequest(http.MethodPost, "", nil)
 		r.Form = v
 
 		a := Int64ValueOrZero(r, "test")
@@ -79,7 +79,7 @@ func TestInt64ValueOrDefault(t *testing.T) {
 	for c, e := range cases {
 		v := url.Values{}
 		v.Set("test", c)
-		r, _ := http.NewRequest("POST", "", nil)
+		r, _ := http.NewRequest(http.MethodPost, "", nil)
 		r.Form = v
 
 		a, err := Int64ValueOrDefault(r, "test", -1)
@@ -95,7 +95,7 @@ func TestInt64ValueOrDefault(t *testing.T) {
 func TestInt64ValueOrDefaultWithError(t *testing.T) {
 	v := url.Values{}
 	v.Set("test", "invalid")
-	r, _ := http.NewRequest("POST", "", nil)
+	r, _ := http.NewRequest(http.MethodPost, "", nil)
 	r.Form = v
 
 	_, err := Int64ValueOrDefault(r, "test", -1)

api/server/middleware/debug.go

@@ -18,7 +18,7 @@ func DebugRequestMiddleware(handler func(ctx context.Context, w http.ResponseWri
 	return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 		logrus.Debugf("Calling %s %s", r.Method, r.RequestURI)
 
-		if r.Method != "POST" {
+		if r.Method != http.MethodPost {
 			return handler(ctx, w, r, vars)
 		}
 		if err := httputils.CheckForJSON(r); err != nil {

api/server/middleware/version_test.go

@@ -25,7 +25,7 @@ func TestVersionMiddlewareVersion(t *testing.T) {
 	m := NewVersionMiddleware(defaultVersion, defaultVersion, minVersion)
 	h := m.WrapHandler(handler)
 
-	req, _ := http.NewRequest("GET", "/containers/json", nil)
+	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
 	resp := httptest.NewRecorder()
 	ctx := context.Background()
 
@@ -76,7 +76,7 @@ func TestVersionMiddlewareWithErrorsReturnsHeaders(t *testing.T) {
 	m := NewVersionMiddleware(defaultVersion, defaultVersion, minVersion)
 	h := m.WrapHandler(handler)
 
-	req, _ := http.NewRequest("GET", "/containers/json", nil)
+	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
 	resp := httptest.NewRecorder()
 	ctx := context.Background()
 

api/server/server_test.go

@@ -22,7 +22,7 @@ func TestMiddlewares(t *testing.T) {
 
 	srv.UseMiddleware(middleware.NewVersionMiddleware("0.1omega2", api.DefaultVersion, api.MinVersion))
 
-	req, _ := http.NewRequest("GET", "/containers/json", nil)
+	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
 	resp := httptest.NewRecorder()
 	ctx := context.Background()
 

builder/builder-next/reqbodyhandler.go

@@ -42,7 +42,7 @@ func (h *reqBodyHandler) newRequest(rc io.ReadCloser) (string, func()) {
 func (h *reqBodyHandler) RoundTrip(req *http.Request) (*http.Response, error) {
 	host := req.URL.Host
 	if strings.HasPrefix(host, urlPrefix) {
-		if req.Method != "GET" {
+		if req.Method != http.MethodGet {
 			return nil, errors.Errorf("invalid request")
 		}
 		id := strings.TrimPrefix(host, urlPrefix)
@@ -57,7 +57,7 @@ func (h *reqBodyHandler) RoundTrip(req *http.Request) (*http.Response, error) {
 
 		resp := &http.Response{
 			Status:        "200 OK",
-			StatusCode:    200,
+			StatusCode:    http.StatusOK,
 			Body:          rc,
 			ContentLength: -1,
 		}

client/checkpoint_create_test.go

@@ -42,7 +42,7 @@ func TestCheckpointCreate(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 

client/checkpoint_delete_test.go

@@ -38,7 +38,7 @@ func TestCheckpointDelete(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/config_create_test.go

@@ -48,7 +48,7 @@ func TestConfigCreate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			b, err := json.Marshal(types.ConfigCreateResponse{

client/config_remove_test.go

@@ -47,7 +47,7 @@ func TestConfigRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/config_update_test.go

@@ -48,7 +48,7 @@ func TestConfigUpdate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/container_copy_test.go

@@ -61,7 +61,7 @@ func TestContainerStatPath(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "HEAD" {
+			if req.Method != http.MethodHead {
 				return nil, fmt.Errorf("expected HEAD method, got %s", req.Method)
 			}
 			query := req.URL.Query()
@@ -140,7 +140,7 @@ func TestCopyToContainer(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "PUT" {
+			if req.Method != http.MethodPut {
 				return nil, fmt.Errorf("expected PUT method, got %s", req.Method)
 			}
 			query := req.URL.Query()
@@ -235,7 +235,7 @@ func TestCopyFromContainer(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "GET" {
+			if req.Method != http.MethodGet {
 				return nil, fmt.Errorf("expected GET method, got %s", req.Method)
 			}
 			query := req.URL.Query()

client/container_exec_test.go

@@ -34,7 +34,7 @@ func TestContainerExecCreate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			// FIXME validate the content is the given ExecConfig ?

client/hijack.go

@@ -24,7 +24,7 @@ func (cli *Client) postHijacked(ctx context.Context, path string, query url.Valu
 	}
 
 	apiPath := cli.getAPIPath(ctx, path, query)
-	req, err := http.NewRequest("POST", apiPath, bodyEncoded)
+	req, err := http.NewRequest(http.MethodPost, apiPath, bodyEncoded)
 	if err != nil {
 		return types.HijackedResponse{}, err
 	}
@@ -40,7 +40,7 @@ func (cli *Client) postHijacked(ctx context.Context, path string, query url.Valu
 
 // DialHijack returns a hijacked connection with negotiated protocol proto.
 func (cli *Client) DialHijack(ctx context.Context, url, proto string, meta map[string][]string) (net.Conn, error) {
-	req, err := http.NewRequest("POST", url, nil)
+	req, err := http.NewRequest(http.MethodPost, url, nil)
 	if err != nil {
 		return nil, err
 	}

client/hijack_test.go

@@ -25,13 +25,13 @@ func TestTLSCloseWriter(t *testing.T) {
 		defer close(chErr)
 		if err := httputils.ParseForm(req); err != nil {
 			chErr <- errors.Wrap(err, "error parsing form")
-			http.Error(w, err.Error(), 500)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 		r, rw, err := httputils.HijackConnection(w)
 		if err != nil {
 			chErr <- errors.Wrap(err, "error hijacking connection")
-			http.Error(w, err.Error(), 500)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 		defer r.Close()

client/image_remove_test.go

@@ -63,7 +63,7 @@ func TestImageRemove(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "DELETE" {
+				if req.Method != http.MethodDelete {
 					return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 				}
 				query := req.URL.Query()

client/image_tag_test.go

@@ -123,7 +123,7 @@ func TestImageTag(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "POST" {
+				if req.Method != http.MethodPost {
 					return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 				}
 				query := req.URL.Query()

client/network_connect_test.go

@@ -38,7 +38,7 @@ func TestNetworkConnectEmptyNilEndpointSettings(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 
@@ -77,7 +77,7 @@ func TestNetworkConnect(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 

client/network_create_test.go

@@ -37,7 +37,7 @@ func TestNetworkCreate(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 

client/network_disconnect_test.go

@@ -37,7 +37,7 @@ func TestNetworkDisconnect(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 

client/network_inspect_test.go

@@ -55,7 +55,7 @@ func TestNetworkInspect(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "GET" {
+			if req.Method != http.MethodGet {
 				return nil, fmt.Errorf("expected GET method, got %s", req.Method)
 			}
 

client/network_list_test.go

@@ -77,7 +77,7 @@ func TestNetworkList(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "GET" {
+				if req.Method != http.MethodGet {
 					return nil, fmt.Errorf("expected GET method, got %s", req.Method)
 				}
 				query := req.URL.Query()

client/network_remove_test.go

@@ -34,7 +34,7 @@ func TestNetworkRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/node_remove_test.go

@@ -49,7 +49,7 @@ func TestNodeRemove(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "DELETE" {
+				if req.Method != http.MethodDelete {
 					return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 				}
 				force := req.URL.Query().Get("force")

client/node_update_test.go

@@ -35,7 +35,7 @@ func TestNodeUpdate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/ping.go

@@ -19,7 +19,7 @@ func (cli *Client) Ping(ctx context.Context) (types.Ping, error) {
 	// Using cli.buildRequest() + cli.doRequest() instead of cli.sendRequest()
 	// because ping requests are used during  API version negotiation, so we want
 	// to hit the non-versioned /_ping endpoint, not /v1.xx/_ping
-	req, err := cli.buildRequest("HEAD", path.Join(cli.basePath, "/_ping"), nil, nil)
+	req, err := cli.buildRequest(http.MethodHead, path.Join(cli.basePath, "/_ping"), nil, nil)
 	if err != nil {
 		return ping, err
 	}
@@ -35,7 +35,7 @@ func (cli *Client) Ping(ctx context.Context) (types.Ping, error) {
 		return ping, err
 	}
 
-	req, err = cli.buildRequest("GET", path.Join(cli.basePath, "/_ping"), nil, nil)
+	req, err = cli.buildRequest(http.MethodGet, path.Join(cli.basePath, "/_ping"), nil, nil)
 	if err != nil {
 		return ping, err
 	}

client/ping_test.go

@@ -90,11 +90,11 @@ func TestPingHeadFallback(t *testing.T) {
 	}{
 		{
 			status:   http.StatusOK,
-			expected: "HEAD",
+			expected: http.MethodHead,
 		},
 		{
 			status:   http.StatusInternalServerError,
-			expected: "HEAD",
+			expected: http.MethodHead,
 		},
 		{
 			status:   http.StatusNotFound,

client/plugin_disable_test.go

@@ -35,7 +35,7 @@ func TestPluginDisable(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/plugin_enable_test.go

@@ -35,7 +35,7 @@ func TestPluginEnable(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/plugin_push_test.go

@@ -34,7 +34,7 @@ func TestPluginPush(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			auth := req.Header.Get("X-Registry-Auth")

client/plugin_remove_test.go

@@ -35,7 +35,7 @@ func TestPluginRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/plugin_set_test.go

@@ -34,7 +34,7 @@ func TestPluginSet(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/request.go

@@ -29,12 +29,12 @@ type serverResponse struct {
 
 // head sends an http request to the docker API using the method HEAD.
 func (cli *Client) head(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
-	return cli.sendRequest(ctx, "HEAD", path, query, nil, headers)
+	return cli.sendRequest(ctx, http.MethodHead, path, query, nil, headers)
 }
 
 // get sends an http request to the docker API using the method GET with a specific Go context.
 func (cli *Client) get(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
-	return cli.sendRequest(ctx, "GET", path, query, nil, headers)
+	return cli.sendRequest(ctx, http.MethodGet, path, query, nil, headers)
 }
 
 // post sends an http request to the docker API using the method POST with a specific Go context.
@@ -43,21 +43,21 @@ func (cli *Client) post(ctx context.Context, path string, query url.Values, obj
 	if err != nil {
 		return serverResponse{}, err
 	}
-	return cli.sendRequest(ctx, "POST", path, query, body, headers)
+	return cli.sendRequest(ctx, http.MethodPost, path, query, body, headers)
 }
 
 func (cli *Client) postRaw(ctx context.Context, path string, query url.Values, body io.Reader, headers map[string][]string) (serverResponse, error) {
-	return cli.sendRequest(ctx, "POST", path, query, body, headers)
+	return cli.sendRequest(ctx, http.MethodPost, path, query, body, headers)
 }
 
 // putRaw sends an http request to the docker API using the method PUT.
 func (cli *Client) putRaw(ctx context.Context, path string, query url.Values, body io.Reader, headers map[string][]string) (serverResponse, error) {
-	return cli.sendRequest(ctx, "PUT", path, query, body, headers)
+	return cli.sendRequest(ctx, http.MethodPut, path, query, body, headers)
 }
 
 // delete sends an http request to the docker API using the method DELETE.
 func (cli *Client) delete(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
-	return cli.sendRequest(ctx, "DELETE", path, query, nil, headers)
+	return cli.sendRequest(ctx, http.MethodDelete, path, query, nil, headers)
 }
 
 type headers map[string][]string
@@ -79,7 +79,7 @@ func encodeBody(obj interface{}, headers headers) (io.Reader, headers, error) {
 }
 
 func (cli *Client) buildRequest(method, path string, body io.Reader, headers headers) (*http.Request, error) {
-	expectedPayload := (method == "POST" || method == "PUT")
+	expectedPayload := (method == http.MethodPost || method == http.MethodPut)
 	if expectedPayload && body == nil {
 		body = bytes.NewReader([]byte{})
 	}

client/request_test.go

@@ -73,7 +73,7 @@ func TestSetHostHeader(t *testing.T) {
 			basePath: hostURL.Path,
 		}
 
-		_, err = client.sendRequest(context.Background(), "GET", testURL, nil, nil, nil)
+		_, err = client.sendRequest(context.Background(), http.MethodGet, testURL, nil, nil, nil)
 		assert.NilError(t, err)
 	}
 }

client/secret_create_test.go

@@ -48,7 +48,7 @@ func TestSecretCreate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			b, err := json.Marshal(types.SecretCreateResponse{

client/secret_remove_test.go

@@ -47,7 +47,7 @@ func TestSecretRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/secret_update_test.go

@@ -48,7 +48,7 @@ func TestSecretUpdate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/service_create_test.go

@@ -40,7 +40,7 @@ func TestServiceCreate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			b, err := json.Marshal(types.ServiceCreateResponse{

client/service_remove_test.go

@@ -40,7 +40,7 @@ func TestServiceRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

client/service_update_test.go

@@ -58,7 +58,7 @@ func TestServiceUpdate(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "POST" {
+				if req.Method != http.MethodPost {
 					return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 				}
 				version := req.URL.Query().Get("version")

client/swarm_get_unlock_key_test.go

@@ -33,7 +33,7 @@ func TestSwarmGetUnlockKey(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "GET" {
+			if req.Method != http.MethodGet {
 				return nil, fmt.Errorf("expected GET method, got %s", req.Method)
 			}
 

client/swarm_init_test.go

@@ -35,7 +35,7 @@ func TestSwarmInit(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/swarm_join_test.go

@@ -35,7 +35,7 @@ func TestSwarmJoin(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/swarm_leave_test.go

@@ -48,7 +48,7 @@ func TestSwarmLeave(t *testing.T) {
 				if !strings.HasPrefix(req.URL.Path, expectedURL) {
 					return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 				}
-				if req.Method != "POST" {
+				if req.Method != http.MethodPost {
 					return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 				}
 				force := req.URL.Query().Get("force")

client/swarm_unlock_test.go

@@ -35,7 +35,7 @@ func TestSwarmUnlock(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/swarm_update_test.go

@@ -35,7 +35,7 @@ func TestSwarmUpdate(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 			return &http.Response{

client/volume_create_test.go

@@ -38,7 +38,7 @@ func TestVolumeCreate(t *testing.T) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
 
-			if req.Method != "POST" {
+			if req.Method != http.MethodPost {
 				return nil, fmt.Errorf("expected POST method, got %s", req.Method)
 			}
 

client/volume_inspect_test.go

@@ -59,7 +59,7 @@ func TestVolumeInspect(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "GET" {
+			if req.Method != http.MethodGet {
 				return nil, fmt.Errorf("expected GET method, got %s", req.Method)
 			}
 			content, err := json.Marshal(expected)

client/volume_remove_test.go

@@ -34,7 +34,7 @@ func TestVolumeRemove(t *testing.T) {
 			if !strings.HasPrefix(req.URL.Path, expectedURL) {
 				return nil, fmt.Errorf("Expected URL '%s', got '%s'", expectedURL, req.URL)
 			}
-			if req.Method != "DELETE" {
+			if req.Method != http.MethodDelete {
 				return nil, fmt.Errorf("expected DELETE method, got %s", req.Method)
 			}
 			return &http.Response{

daemon/logger/splunk/splunk.go

@@ -507,7 +507,7 @@ func (l *splunkLogger) tryPostMessages(ctx context.Context, messages []*splunkMe
 			return err
 		}
 	}
-	req, err := http.NewRequest("POST", l.url, bytes.NewBuffer(buffer.Bytes()))
+	req, err := http.NewRequest(http.MethodPost, l.url, bytes.NewBuffer(buffer.Bytes()))
 	if err != nil {
 		return err
 	}

daemon/logger/splunk/splunk_test.go

@@ -105,7 +105,7 @@ func TestNewWithProxy(t *testing.T) {
 	proxyFunc := splunkLogger.transport.Proxy
 	assert.Assert(t, proxyFunc != nil)
 
-	req, err := http.NewRequest("GET", splunkURL, nil)
+	req, err := http.NewRequest(http.MethodGet, splunkURL, nil)
 	assert.NilError(t, err)
 
 	proxyURL, err := proxyFunc(req)

integration-cli/docker_api_attach_test.go

@@ -142,12 +142,12 @@ func (s *DockerSuite) TestPostContainersAttach(c *testing.T) {
 	cid, _ := dockerCmd(c, "run", "-di", "busybox", "cat")
 	cid = strings.TrimSpace(cid)
 	// Attach to the container's stdout stream.
-	conn, br, err := sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err := sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	// Check if the data from stdout can be received.
 	expectSuccess(conn, br, "stdout", false)
 	// Attach to the container's stderr stream.
-	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err = sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	// Since the container only emits stdout, attaching to stderr should return nothing.
 	expectTimeout(conn, br, "stdout")
@@ -155,10 +155,10 @@ func (s *DockerSuite) TestPostContainersAttach(c *testing.T) {
 	// Test the similar functions of the stderr stream.
 	cid, _ = dockerCmd(c, "run", "-di", "busybox", "/bin/sh", "-c", "cat >&2")
 	cid = strings.TrimSpace(cid)
-	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err = sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	expectSuccess(conn, br, "stderr", false)
-	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err = sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	expectTimeout(conn, br, "stderr")
 
@@ -166,12 +166,12 @@ func (s *DockerSuite) TestPostContainersAttach(c *testing.T) {
 	cid, _ = dockerCmd(c, "run", "-dit", "busybox", "/bin/sh", "-c", "cat >&2")
 	cid = strings.TrimSpace(cid)
 	// Attach to stdout only.
-	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err = sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stdout=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	expectSuccess(conn, br, "stdout", true)
 
 	// Attach without stdout stream.
-	conn, br, err = sockRequestHijack("POST", "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
+	conn, br, err = sockRequestHijack(http.MethodPost, "/containers/"+cid+"/attach?stream=1&stdin=1&stderr=1", nil, "text/plain", request.DaemonHost())
 	assert.NilError(c, err)
 	// Nothing should be received because both the stdout and stderr of the container will be
 	// sent to the client as stdout when tty is enabled.

integration-cli/docker_api_exec_resize_test.go

@@ -65,7 +65,7 @@ func (s *DockerSuite) TestExecResizeImmediatelyAfterExecStart(c *testing.T) {
 		}
 
 		payload := bytes.NewBufferString(`{"Tty":true}`)
-		conn, _, err := sockRequestHijack("POST", fmt.Sprintf("/exec/%s/start", execID), payload, "application/json", request.DaemonHost())
+		conn, _, err := sockRequestHijack(http.MethodPost, fmt.Sprintf("/exec/%s/start", execID), payload, "application/json", request.DaemonHost())
 		if err != nil {
 			return errors.Wrap(err, "failed to start the exec")
 		}

integration/plugin/authz/authz_plugin_test.go

@@ -178,7 +178,7 @@ func TestAuthZPluginAPIDenyResponse(t *testing.T) {
 	conn, err := net.DialTimeout(daemonURL.Scheme, daemonURL.Path, time.Second*10)
 	assert.NilError(t, err)
 	c := httputil.NewClientConn(conn, nil)
-	req, err := http.NewRequest("GET", "/version", nil)
+	req, err := http.NewRequest(http.MethodGet, "/version", nil)
 	assert.NilError(t, err)
 	resp, err := c.Do(req)
 
@@ -477,7 +477,7 @@ func TestAuthZPluginHeader(t *testing.T) {
 	conn, err := net.DialTimeout(daemonURL.Scheme, daemonURL.Path, time.Second*10)
 	assert.NilError(t, err)
 	client := httputil.NewClientConn(conn, nil)
-	req, err := http.NewRequest("GET", "/version", nil)
+	req, err := http.NewRequest(http.MethodGet, "/version", nil)
 	assert.NilError(t, err)
 	resp, err := client.Do(req)
 	assert.NilError(t, err)

pkg/authorization/api_test.go

@@ -46,7 +46,7 @@ func TestPeerCertificateMarshalJSON(t *testing.T) {
 
 	var certs = []*x509.Certificate{cert}
 	addr := "www.authz.com/auth"
-	req, err := http.NewRequest("GET", addr, nil)
+	req, err := http.NewRequest(http.MethodGet, addr, nil)
 	assert.NilError(t, err)
 
 	req.RequestURI = addr

pkg/authorization/authz_unix_test.go

@@ -38,7 +38,7 @@ func TestAuthZRequestPluginError(t *testing.T) {
 		User:           "user",
 		RequestBody:    []byte("sample body"),
 		RequestURI:     "www.authz.com/auth",
-		RequestMethod:  "GET",
+		RequestMethod:  http.MethodGet,
 		RequestHeaders: map[string]string{"header": "value"},
 	}
 	server.replayResponse = Response{
@@ -69,7 +69,7 @@ func TestAuthZRequestPlugin(t *testing.T) {
 		User:           "user",
 		RequestBody:    []byte("sample body"),
 		RequestURI:     "www.authz.com/auth",
-		RequestMethod:  "GET",
+		RequestMethod:  http.MethodGet,
 		RequestHeaders: map[string]string{"header": "value"},
 	}
 	server.replayResponse = Response{

pkg/authorization/middleware_unix_test.go

@@ -34,7 +34,7 @@ func TestMiddlewareWrapHandler(t *testing.T) {
 	assert.Assert(t, mdHandler != nil)
 
 	addr := "www.example.com/auth"
-	req, _ := http.NewRequest("GET", addr, nil)
+	req, _ := http.NewRequest(http.MethodGet, addr, nil)
 	req.RequestURI = addr
 	req.Header.Add("header", "value")
 

pkg/plugins/client_test.go

@@ -70,7 +70,7 @@ func TestEchoInputOutput(t *testing.T) {
 	m := Manifest{[]string{"VolumeDriver", "NetworkDriver"}}
 
 	mux.HandleFunc("/Test.Echo", func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != "POST" {
+		if r.Method != http.MethodPost {
 			t.Fatalf("Expected POST, got %s\n", r.Method)
 		}
 
@@ -185,7 +185,7 @@ func TestClientStream(t *testing.T) {
 	var output Manifest
 
 	mux.HandleFunc("/Test.Echo", func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != "POST" {
+		if r.Method != http.MethodPost {
 			t.Fatalf("Expected POST, got %s", r.Method)
 		}
 
@@ -218,7 +218,7 @@ func TestClientSendFile(t *testing.T) {
 		t.Fatal(err)
 	}
 	mux.HandleFunc("/Test.Echo", func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != "POST" {
+		if r.Method != http.MethodPost {
 			t.Fatalf("Expected POST, got %s\n", r.Method)
 		}
 
@@ -263,7 +263,7 @@ type testRequestWrapper struct {
 }
 
 func (w *testRequestWrapper) NewRequest(path string, data io.Reader) (*http.Request, error) {
-	req, err := http.NewRequest("POST", path, data)
+	req, err := http.NewRequest(http.MethodPost, path, data)
 	if err != nil {
 		return nil, err
 	}

pkg/plugins/plugin_test.go

@@ -95,7 +95,7 @@ func TestPluginWithNoManifest(t *testing.T) {
 	}
 
 	mux.HandleFunc("/Plugin.Activate", func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != "POST" {
+		if r.Method != http.MethodPost {
 			t.Fatalf("Expected POST, got %s\n", r.Method)
 		}
 

pkg/plugins/transport/http_test.go

@@ -17,5 +17,5 @@ func TestHTTPTransport(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	assert.Check(t, is.Equal("POST", request.Method))
+	assert.Check(t, is.Equal(http.MethodPost, request.Method))
 }

pkg/plugins/transport/transport.go

@@ -27,7 +27,7 @@ func newHTTPRequest(path string, data io.Reader) (*http.Request, error) {
 	if !strings.HasPrefix(path, "/") {
 		path = "/" + path
 	}
-	req, err := http.NewRequest("POST", path, data)
+	req, err := http.NewRequest(http.MethodPost, path, data)
 	if err != nil {
 		return nil, err
 	}

registry/auth.go

@@ -33,7 +33,7 @@ func loginV1(authConfig *types.AuthConfig, apiEndpoint APIEndpoint, userAgent st
 		return "", "", errdefs.System(errors.New("server Error: Server Address not set"))
 	}
 
-	req, err := http.NewRequest("GET", serverAddress+"users/", nil)
+	req, err := http.NewRequest(http.MethodGet, serverAddress+"users/", nil)
 	if err != nil {
 		return "", "", err
 	}
@@ -140,7 +140,7 @@ func loginV2(authConfig *types.AuthConfig, endpoint APIEndpoint, userAgent strin
 	}
 
 	endpointStr := strings.TrimRight(endpoint.URL.String(), "/") + "/v2/"
-	req, err := http.NewRequest("GET", endpointStr, nil)
+	req, err := http.NewRequest(http.MethodGet, endpointStr, nil)
 	if err != nil {
 		if !foundV2 {
 			err = fallbackError{err: err}
@@ -262,7 +262,7 @@ func PingV2Registry(endpoint *url.URL, transport http.RoundTripper) (challenge.M
 		Timeout:   15 * time.Second,
 	}
 	endpointStr := strings.TrimRight(endpoint.String(), "/") + "/v2/"
-	req, err := http.NewRequest("GET", endpointStr, nil)
+	req, err := http.NewRequest(http.MethodGet, endpointStr, nil)
 	if err != nil {
 		return nil, false, err
 	}

registry/endpoint_v1.go

@@ -149,7 +149,7 @@ func (e *V1Endpoint) Ping() (PingResult, error) {
 		return PingResult{Standalone: false}, nil
 	}
 
-	req, err := http.NewRequest("GET", e.Path("_ping"), nil)
+	req, err := http.NewRequest(http.MethodGet, e.Path("_ping"), nil)
 	if err != nil {
 		return PingResult{Standalone: false}, err
 	}

registry/registry_mock_test.go

@@ -97,19 +97,19 @@ func init() {
 	r := mux.NewRouter()
 
 	// /v1/
-	r.HandleFunc("/v1/_ping", handlerGetPing).Methods("GET")
-	r.HandleFunc("/v1/images/{image_id:[^/]+}/{action:json|layer|ancestry}", handlerGetImage).Methods("GET")
-	r.HandleFunc("/v1/images/{image_id:[^/]+}/{action:json|layer|checksum}", handlerPutImage).Methods("PUT")
-	r.HandleFunc("/v1/repositories/{repository:.+}/tags", handlerGetDeleteTags).Methods("GET", "DELETE")
-	r.HandleFunc("/v1/repositories/{repository:.+}/tags/{tag:.+}", handlerGetTag).Methods("GET")
-	r.HandleFunc("/v1/repositories/{repository:.+}/tags/{tag:.+}", handlerPutTag).Methods("PUT")
-	r.HandleFunc("/v1/users{null:.*}", handlerUsers).Methods("GET", "POST", "PUT")
-	r.HandleFunc("/v1/repositories/{repository:.+}{action:/images|/}", handlerImages).Methods("GET", "PUT", "DELETE")
-	r.HandleFunc("/v1/repositories/{repository:.+}/auth", handlerAuth).Methods("PUT")
-	r.HandleFunc("/v1/search", handlerSearch).Methods("GET")
+	r.HandleFunc("/v1/_ping", handlerGetPing).Methods(http.MethodGet)
+	r.HandleFunc("/v1/images/{image_id:[^/]+}/{action:json|layer|ancestry}", handlerGetImage).Methods(http.MethodGet)
+	r.HandleFunc("/v1/images/{image_id:[^/]+}/{action:json|layer|checksum}", handlerPutImage).Methods(http.MethodPut)
+	r.HandleFunc("/v1/repositories/{repository:.+}/tags", handlerGetDeleteTags).Methods(http.MethodGet, http.MethodDelete)
+	r.HandleFunc("/v1/repositories/{repository:.+}/tags/{tag:.+}", handlerGetTag).Methods(http.MethodGet)
+	r.HandleFunc("/v1/repositories/{repository:.+}/tags/{tag:.+}", handlerPutTag).Methods(http.MethodPut)
+	r.HandleFunc("/v1/users{null:.*}", handlerUsers).Methods(http.MethodGet, http.MethodPost, http.MethodPut)
+	r.HandleFunc("/v1/repositories/{repository:.+}{action:/images|/}", handlerImages).Methods(http.MethodGet, http.MethodPut, http.MethodDelete)
+	r.HandleFunc("/v1/repositories/{repository:.+}/auth", handlerAuth).Methods(http.MethodPut)
+	r.HandleFunc("/v1/search", handlerSearch).Methods(http.MethodGet)
 
 	// /v2/
-	r.HandleFunc("/v2/version", handlerGetPing).Methods("GET")
+	r.HandleFunc("/v2/version", handlerGetPing).Methods(http.MethodGet)
 
 	testHTTPServer = httptest.NewServer(handlerAccessLog(r))
 	testHTTPSServer = httptest.NewTLSServer(handlerAccessLog(r))
@@ -281,12 +281,12 @@ func requiresAuth(w http.ResponseWriter, r *http.Request) bool {
 		return true
 	}
 	w.Header().Add("WWW-Authenticate", "token")
-	apiError(w, "Wrong auth", 401)
+	apiError(w, "Wrong auth", http.StatusUnauthorized)
 	return false
 }
 
 func handlerGetPing(w http.ResponseWriter, r *http.Request) {
-	writeResponse(w, true, 200)
+	writeResponse(w, true, http.StatusOK)
 }
 
 func handlerGetImage(w http.ResponseWriter, r *http.Request) {
@@ -323,17 +323,17 @@ func handlerPutImage(w http.ResponseWriter, r *http.Request) {
 	}
 	if checksum := r.Header.Get("X-Docker-Checksum"); checksum != "" {
 		if checksum != layer["checksum_simple"] && checksum != layer["checksum_tarsum"] {
-			apiError(w, "Wrong checksum", 400)
+			apiError(w, "Wrong checksum", http.StatusBadRequest)
 			return
 		}
 	}
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
-		apiError(w, fmt.Sprintf("Error: %s", err), 500)
+		apiError(w, fmt.Sprintf("Error: %s", err), http.StatusInternalServerError)
 		return
 	}
 	layer[action] = string(body)
-	writeResponse(w, true, 200)
+	writeResponse(w, true, http.StatusOK)
 }
 
 func handlerGetDeleteTags(w http.ResponseWriter, r *http.Request) {
@@ -342,20 +342,20 @@ func handlerGetDeleteTags(w http.ResponseWriter, r *http.Request) {
 	}
 	repositoryName, err := reference.WithName(mux.Vars(r)["repository"])
 	if err != nil {
-		apiError(w, "Could not parse repository", 400)
+		apiError(w, "Could not parse repository", http.StatusBadRequest)
 		return
 	}
 	tags, exists := testRepositories[repositoryName.String()]
 	if !exists {
-		apiError(w, "Repository not found", 404)
+		apiError(w, "Repository not found", http.StatusNotFound)
 		return
 	}
-	if r.Method == "DELETE" {
+	if r.Method == http.MethodDelete {
 		delete(testRepositories, repositoryName.String())
-		writeResponse(w, true, 200)
+		writeResponse(w, true, http.StatusOK)
 		return
 	}
-	writeResponse(w, tags, 200)
+	writeResponse(w, tags, http.StatusOK)
 }
 
 func handlerGetTag(w http.ResponseWriter, r *http.Request) {
@@ -365,21 +365,21 @@ func handlerGetTag(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	repositoryName, err := reference.WithName(vars["repository"])
 	if err != nil {
-		apiError(w, "Could not parse repository", 400)
+		apiError(w, "Could not parse repository", http.StatusBadRequest)
 		return
 	}
 	tagName := vars["tag"]
 	tags, exists := testRepositories[repositoryName.String()]
 	if !exists {
-		apiError(w, "Repository not found", 404)
+		apiError(w, "Repository not found", http.StatusNotFound)
 		return
 	}
 	tag, exists := tags[tagName]
 	if !exists {
-		apiError(w, "Tag not found", 404)
+		apiError(w, "Tag not found", http.StatusNotFound)
 		return
 	}
-	writeResponse(w, tag, 200)
+	writeResponse(w, tag, http.StatusOK)
 }
 
 func handlerPutTag(w http.ResponseWriter, r *http.Request) {
@@ -389,7 +389,7 @@ func handlerPutTag(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	repositoryName, err := reference.WithName(vars["repository"])
 	if err != nil {
-		apiError(w, "Could not parse repository", 400)
+		apiError(w, "Could not parse repository", http.StatusBadRequest)
 		return
 	}
 	tagName := vars["tag"]
@@ -401,15 +401,15 @@ func handlerPutTag(w http.ResponseWriter, r *http.Request) {
 	tagValue := ""
 	readJSON(r, tagValue)
 	tags[tagName] = tagValue
-	writeResponse(w, true, 200)
+	writeResponse(w, true, http.StatusOK)
 }
 
 func handlerUsers(w http.ResponseWriter, r *http.Request) {
-	code := 200
-	if r.Method == "POST" {
-		code = 201
-	} else if r.Method == "PUT" {
-		code = 204
+	code := http.StatusOK
+	if r.Method == http.MethodPost {
+		code = http.StatusCreated
+	} else if r.Method == http.MethodPut {
+		code = http.StatusNoContent
 	}
 	writeResponse(w, "", code)
 }
@@ -418,16 +418,16 @@ func handlerImages(w http.ResponseWriter, r *http.Request) {
 	u, _ := url.Parse(testHTTPServer.URL)
 	w.Header().Add("X-Docker-Endpoints", fmt.Sprintf("%s 	,  %s ", u.Host, "test.example.com"))
 	w.Header().Add("X-Docker-Token", fmt.Sprintf("FAKE-SESSION-%d", time.Now().UnixNano()))
-	if r.Method == "PUT" {
+	if r.Method == http.MethodPut {
 		if strings.HasSuffix(r.URL.Path, "images") {
-			writeResponse(w, "", 204)
+			writeResponse(w, "", http.StatusNoContent)
 			return
 		}
-		writeResponse(w, "", 200)
+		writeResponse(w, "", http.StatusOK)
 		return
 	}
-	if r.Method == "DELETE" {
-		writeResponse(w, "", 204)
+	if r.Method == http.MethodDelete {
+		writeResponse(w, "", http.StatusNoContent)
 		return
 	}
 	var images []map[string]string
@@ -438,11 +438,11 @@ func handlerImages(w http.ResponseWriter, r *http.Request) {
 		image["Tag"] = "latest"
 		images = append(images, image)
 	}
-	writeResponse(w, images, 200)
+	writeResponse(w, images, http.StatusOK)
 }
 
 func handlerAuth(w http.ResponseWriter, r *http.Request) {
-	writeResponse(w, "OK", 200)
+	writeResponse(w, "OK", http.StatusOK)
 }
 
 func handlerSearch(w http.ResponseWriter, r *http.Request) {
@@ -451,7 +451,7 @@ func handlerSearch(w http.ResponseWriter, r *http.Request) {
 		NumResults: 1,
 		Results:    []registrytypes.SearchResult{{Name: "fakeimage", StarCount: 42}},
 	}
-	writeResponse(w, result, 200)
+	writeResponse(w, result, http.StatusOK)
 }
 
 func TestPing(t *testing.T) {
@@ -459,7 +459,7 @@ func TestPing(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	assertEqual(t, res.StatusCode, 200, "")
+	assertEqual(t, res.StatusCode, http.StatusOK, "")
 	assertEqual(t, res.Header.Get("X-Docker-Registry-Config"), "mock",
 		"This is not a Mocked Registry")
 }

registry/registry_test.go

@@ -761,12 +761,12 @@ func TestSearchRepositories(t *testing.T) {
 
 func TestTrustedLocation(t *testing.T) {
 	for _, url := range []string{"http://example.com", "https://example.com:7777", "http://docker.io", "http://test.docker.com", "https://fakedocker.com"} {
-		req, _ := http.NewRequest("GET", url, nil)
+		req, _ := http.NewRequest(http.MethodGet, url, nil)
 		assert.Check(t, !trustedLocation(req))
 	}
 
 	for _, url := range []string{"https://docker.io", "https://test.docker.com:80"} {
-		req, _ := http.NewRequest("GET", url, nil)
+		req, _ := http.NewRequest(http.MethodGet, url, nil)
 		assert.Check(t, trustedLocation(req))
 	}
 }
@@ -777,10 +777,10 @@ func TestAddRequiredHeadersToRedirectedRequests(t *testing.T) {
 		{"https://foo.docker.io:7777", "http://bar.docker.com"},
 		{"https://foo.docker.io", "https://example.com"},
 	} {
-		reqFrom, _ := http.NewRequest("GET", urls[0], nil)
+		reqFrom, _ := http.NewRequest(http.MethodGet, urls[0], nil)
 		reqFrom.Header.Add("Content-Type", "application/json")
 		reqFrom.Header.Add("Authorization", "super_secret")
-		reqTo, _ := http.NewRequest("GET", urls[1], nil)
+		reqTo, _ := http.NewRequest(http.MethodGet, urls[1], nil)
 
 		addRequiredHeadersToRedirectedRequests(reqTo, []*http.Request{reqFrom})
 
@@ -801,10 +801,10 @@ func TestAddRequiredHeadersToRedirectedRequests(t *testing.T) {
 		{"https://docker.io", "https://docker.com"},
 		{"https://foo.docker.io:7777", "https://bar.docker.com"},
 	} {
-		reqFrom, _ := http.NewRequest("GET", urls[0], nil)
+		reqFrom, _ := http.NewRequest(http.MethodGet, urls[0], nil)
 		reqFrom.Header.Add("Content-Type", "application/json")
 		reqFrom.Header.Add("Authorization", "super_secret")
-		reqTo, _ := http.NewRequest("GET", urls[1], nil)
+		reqTo, _ := http.NewRequest(http.MethodGet, urls[1], nil)
 
 		addRequiredHeadersToRedirectedRequests(reqTo, []*http.Request{reqFrom})
 

registry/resumable/resumablerequestreader.go

@@ -56,10 +56,10 @@ func (r *requestReader) Read(p []byte) (n int, err error) {
 		r.cleanUpResponse()
 		return 0, err
 	}
-	if r.currentResponse.StatusCode == 416 && r.lastRange == r.totalSize && r.currentResponse.ContentLength == 0 {
+	if r.currentResponse.StatusCode == http.StatusRequestedRangeNotSatisfiable && r.lastRange == r.totalSize && r.currentResponse.ContentLength == 0 {
 		r.cleanUpResponse()
 		return 0, io.EOF
-	} else if r.currentResponse.StatusCode != 206 && r.lastRange != 0 && isFreshRequest {
+	} else if r.currentResponse.StatusCode != http.StatusPartialContent && r.lastRange != 0 && isFreshRequest {
 		r.cleanUpResponse()
 		return 0, fmt.Errorf("the server doesn't support byte ranges")
 	}

registry/resumable/resumablerequestreader_test.go

@@ -23,7 +23,7 @@ func TestResumableRequestHeaderSimpleErrors(t *testing.T) {
 	client := &http.Client{}
 
 	var req *http.Request
-	req, err := http.NewRequest("GET", ts.URL, nil)
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
 	assert.NilError(t, err)
 
 	resreq := &requestReader{}
@@ -44,7 +44,7 @@ func TestResumableRequestHeaderNotTooMuchFailures(t *testing.T) {
 	client := &http.Client{}
 
 	var badReq *http.Request
-	badReq, err := http.NewRequest("GET", "I'm not an url", nil)
+	badReq, err := http.NewRequest(http.MethodGet, "I'm not an url", nil)
 	assert.NilError(t, err)
 
 	resreq := &requestReader{
@@ -64,7 +64,7 @@ func TestResumableRequestHeaderTooMuchFailures(t *testing.T) {
 	client := &http.Client{}
 
 	var badReq *http.Request
-	badReq, err := http.NewRequest("GET", "I'm not an url", nil)
+	badReq, err := http.NewRequest(http.MethodGet, "I'm not an url", nil)
 	assert.NilError(t, err)
 
 	resreq := &requestReader{
@@ -92,14 +92,14 @@ func (errorReaderCloser) Read(p []byte) (n int, err error) {
 // If an unknown error is encountered, return 0, nil and log it
 func TestResumableRequestReaderWithReadError(t *testing.T) {
 	var req *http.Request
-	req, err := http.NewRequest("GET", "", nil)
+	req, err := http.NewRequest(http.MethodGet, "", nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}
 
 	response := &http.Response{
 		Status:        "500 Internal Server",
-		StatusCode:    500,
+		StatusCode:    http.StatusInternalServerError,
 		ContentLength: 0,
 		Close:         true,
 		Body:          errorReaderCloser{},
@@ -123,14 +123,14 @@ func TestResumableRequestReaderWithReadError(t *testing.T) {
 
 func TestResumableRequestReaderWithEOFWith416Response(t *testing.T) {
 	var req *http.Request
-	req, err := http.NewRequest("GET", "", nil)
+	req, err := http.NewRequest(http.MethodGet, "", nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}
 
 	response := &http.Response{
 		Status:        "416 Requested Range Not Satisfiable",
-		StatusCode:    416,
+		StatusCode:    http.StatusRequestedRangeNotSatisfiable,
 		ContentLength: 0,
 		Close:         true,
 		Body:          ioutil.NopCloser(strings.NewReader("")),
@@ -159,7 +159,7 @@ func TestResumableRequestReaderWithServerDoesntSupportByteRanges(t *testing.T) {
 	defer ts.Close()
 
 	var req *http.Request
-	req, err := http.NewRequest("GET", ts.URL, nil)
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}
@@ -185,7 +185,7 @@ func TestResumableRequestReaderWithZeroTotalSize(t *testing.T) {
 	defer ts.Close()
 
 	var req *http.Request
-	req, err := http.NewRequest("GET", ts.URL, nil)
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}
@@ -210,7 +210,7 @@ func TestResumableRequestReader(t *testing.T) {
 	defer ts.Close()
 
 	var req *http.Request
-	req, err := http.NewRequest("GET", ts.URL, nil)
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}
@@ -236,7 +236,7 @@ func TestResumableRequestReaderWithInitialResponse(t *testing.T) {
 	defer ts.Close()
 
 	var req *http.Request
-	req, err := http.NewRequest("GET", ts.URL, nil)
+	req, err := http.NewRequest(http.MethodGet, ts.URL, nil)
 	assert.NilError(t, err)
 
 	client := &http.Client{}

registry/session.go

@@ -225,8 +225,8 @@ func (r *Session) GetRemoteHistory(imgID, registry string) ([]string, error) {
 		return nil, err
 	}
 	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		if res.StatusCode == 401 {
+	if res.StatusCode != http.StatusOK {
+		if res.StatusCode == http.StatusUnauthorized {
 			return nil, errcode.ErrorCodeUnauthorized.WithArgs()
 		}
 		return nil, newJSONError(fmt.Sprintf("Server error: %d trying to fetch remote history for %s", res.StatusCode, imgID), res)
@@ -248,7 +248,7 @@ func (r *Session) LookupRemoteImage(imgID, registry string) error {
 		return err
 	}
 	res.Body.Close()
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		return newJSONError(fmt.Sprintf("HTTP code %d", res.StatusCode), res)
 	}
 	return nil
@@ -261,7 +261,7 @@ func (r *Session) GetRemoteImageJSON(imgID, registry string) ([]byte, int64, err
 		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
 	}
 	defer res.Body.Close()
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		return nil, -1, newJSONError(fmt.Sprintf("HTTP code %d", res.StatusCode), res)
 	}
 	// if the size header is not present, then set it to '-1'
@@ -289,7 +289,7 @@ func (r *Session) GetRemoteImageLayer(imgID, registry string, imgSize int64) (io
 		imageURL   = fmt.Sprintf("%simages/%s/layer", registry, imgID)
 	)
 
-	req, err := http.NewRequest("GET", imageURL, nil)
+	req, err := http.NewRequest(http.MethodGet, imageURL, nil)
 	if err != nil {
 		return nil, fmt.Errorf("Error while getting from the server: %v", err)
 	}
@@ -308,7 +308,7 @@ func (r *Session) GetRemoteImageLayer(imgID, registry string, imgSize int64) (io
 			statusCode, imgID)
 	}
 
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		res.Body.Close()
 		return nil, fmt.Errorf("Server error: Status %d while fetching image layer (%s)",
 			res.StatusCode, imgID)
@@ -347,7 +347,7 @@ func (r *Session) GetRemoteTag(registries []string, repositoryRef reference.Name
 		if res.StatusCode == 404 {
 			return "", ErrRepoNotFound
 		}
-		if res.StatusCode != 200 {
+		if res.StatusCode != http.StatusOK {
 			continue
 		}
 
@@ -385,7 +385,7 @@ func (r *Session) GetRemoteTags(registries []string, repositoryRef reference.Nam
 		if res.StatusCode == 404 {
 			return nil, ErrRepoNotFound
 		}
-		if res.StatusCode != 200 {
+		if res.StatusCode != http.StatusOK {
 			continue
 		}
 
@@ -423,7 +423,7 @@ func (r *Session) GetRepositoryData(name reference.Named) (*RepositoryData, erro
 
 	logrus.Debugf("[registry] Calling GET %s", repositoryTarget)
 
-	req, err := http.NewRequest("GET", repositoryTarget, nil)
+	req, err := http.NewRequest(http.MethodGet, repositoryTarget, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -441,14 +441,14 @@ func (r *Session) GetRepositoryData(name reference.Named) (*RepositoryData, erro
 		return nil, fmt.Errorf("Error while pulling image: %v", err)
 	}
 	defer res.Body.Close()
-	if res.StatusCode == 401 {
+	if res.StatusCode == http.StatusUnauthorized {
 		return nil, errcode.ErrorCodeUnauthorized.WithArgs()
 	}
 	// TODO: Right now we're ignoring checksums in the response body.
 	// In the future, we need to use them to check image validity.
 	if res.StatusCode == 404 {
 		return nil, newJSONError(fmt.Sprintf("HTTP code: %d", res.StatusCode), res)
-	} else if res.StatusCode != 200 {
+	} else if res.StatusCode != http.StatusOK {
 		errBody, err := ioutil.ReadAll(res.Body)
 		if err != nil {
 			logrus.Debugf("Error reading response body: %s", err)
@@ -490,7 +490,7 @@ func (r *Session) PushImageChecksumRegistry(imgData *ImgData, registry string) e
 
 	logrus.Debugf("[registry] Calling PUT %s", u)
 
-	req, err := http.NewRequest("PUT", u, nil)
+	req, err := http.NewRequest(http.MethodPut, u, nil)
 	if err != nil {
 		return err
 	}
@@ -505,7 +505,7 @@ func (r *Session) PushImageChecksumRegistry(imgData *ImgData, registry string) e
 	if len(res.Cookies()) > 0 {
 		r.client.Jar.SetCookies(req.URL, res.Cookies())
 	}
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		errBody, err := ioutil.ReadAll(res.Body)
 		if err != nil {
 			return fmt.Errorf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err)
@@ -528,7 +528,7 @@ func (r *Session) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, regist
 
 	logrus.Debugf("[registry] Calling PUT %s", u)
 
-	req, err := http.NewRequest("PUT", u, bytes.NewReader(jsonRaw))
+	req, err := http.NewRequest(http.MethodPut, u, bytes.NewReader(jsonRaw))
 	if err != nil {
 		return err
 	}
@@ -539,10 +539,10 @@ func (r *Session) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, regist
 		return fmt.Errorf("Failed to upload metadata: %s", err)
 	}
 	defer res.Body.Close()
-	if res.StatusCode == 401 && strings.HasPrefix(registry, "http://") {
+	if res.StatusCode == http.StatusUnauthorized && strings.HasPrefix(registry, "http://") {
 		return newJSONError("HTTP code 401, Docker will not send auth headers over HTTP.", res)
 	}
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		errBody, err := ioutil.ReadAll(res.Body)
 		if err != nil {
 			return newJSONError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res)
@@ -573,7 +573,7 @@ func (r *Session) PushImageLayerRegistry(imgID string, layer io.Reader, registry
 	h.Write([]byte{'\n'})
 	checksumLayer := io.TeeReader(tarsumLayer, h)
 
-	req, err := http.NewRequest("PUT", u, checksumLayer)
+	req, err := http.NewRequest(http.MethodPut, u, checksumLayer)
 	if err != nil {
 		return "", "", err
 	}
@@ -591,7 +591,7 @@ func (r *Session) PushImageLayerRegistry(imgID string, layer io.Reader, registry
 	}
 	defer res.Body.Close()
 
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		errBody, err := ioutil.ReadAll(res.Body)
 		if err != nil {
 			return "", "", newJSONError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res)
@@ -610,7 +610,7 @@ func (r *Session) PushRegistryTag(remote reference.Named, revision, tag, registr
 	revision = "\"" + revision + "\""
 	path := fmt.Sprintf("repositories/%s/tags/%s", reference.Path(remote), tag)
 
-	req, err := http.NewRequest("PUT", registry+path, strings.NewReader(revision))
+	req, err := http.NewRequest(http.MethodPut, registry+path, strings.NewReader(revision))
 	if err != nil {
 		return err
 	}
@@ -621,7 +621,7 @@ func (r *Session) PushRegistryTag(remote reference.Named, revision, tag, registr
 		return err
 	}
 	res.Body.Close()
-	if res.StatusCode != 200 && res.StatusCode != 201 {
+	if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated {
 		return newJSONError(fmt.Sprintf("Internal server error: %d trying to push tag %s on %s", res.StatusCode, tag, reference.Path(remote)), res)
 	}
 	return nil
@@ -675,13 +675,13 @@ func (r *Session) PushImageJSONIndex(remote reference.Named, imgList []*ImgData,
 	}
 	defer res.Body.Close()
 
-	if res.StatusCode == 401 {
+	if res.StatusCode == http.StatusUnauthorized {
 		return nil, errcode.ErrorCodeUnauthorized.WithArgs()
 	}
 
 	var tokens, endpoints []string
 	if !validate {
-		if res.StatusCode != 200 && res.StatusCode != 201 {
+		if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated {
 			errBody, err := ioutil.ReadAll(res.Body)
 			if err != nil {
 				logrus.Debugf("Error reading response body: %s", err)
@@ -699,7 +699,7 @@ func (r *Session) PushImageJSONIndex(remote reference.Named, imgList []*ImgData,
 			return nil, err
 		}
 	} else {
-		if res.StatusCode != 204 {
+		if res.StatusCode != http.StatusNoContent {
 			errBody, err := ioutil.ReadAll(res.Body)
 			if err != nil {
 				logrus.Debugf("Error reading response body: %s", err)
@@ -714,7 +714,7 @@ func (r *Session) PushImageJSONIndex(remote reference.Named, imgList []*ImgData,
 }
 
 func (r *Session) putImageRequest(u string, headers map[string][]string, body []byte) (*http.Response, error) {
-	req, err := http.NewRequest("PUT", u, bytes.NewReader(body))
+	req, err := http.NewRequest(http.MethodPut, u, bytes.NewReader(body))
 	if err != nil {
 		return nil, err
 	}
@@ -741,7 +741,7 @@ func (r *Session) SearchRepositories(term string, limit int) (*registrytypes.Sea
 	logrus.Debugf("Index server: %s", r.indexEndpoint)
 	u := r.indexEndpoint.String() + "search?q=" + url.QueryEscape(term) + "&n=" + url.QueryEscape(fmt.Sprintf("%d", limit))
 
-	req, err := http.NewRequest("GET", u, nil)
+	req, err := http.NewRequest(http.MethodGet, u, nil)
 	if err != nil {
 		return nil, errors.Wrap(errdefs.InvalidParameter(err), "Error building request")
 	}
@@ -752,7 +752,7 @@ func (r *Session) SearchRepositories(term string, limit int) (*registrytypes.Sea
 		return nil, errdefs.System(err)
 	}
 	defer res.Body.Close()
-	if res.StatusCode != 200 {
+	if res.StatusCode != http.StatusOK {
 		return nil, newJSONError(fmt.Sprintf("Unexpected status code %d", res.StatusCode), res)
 	}
 	result := new(registrytypes.SearchResults)

testutil/daemon/daemon.go

@@ -329,7 +329,7 @@ func (d *Daemon) StartWithLogFile(out *os.File, providedArgs ...string) error {
 		Transport: clientConfig.transport,
 	}
 
-	req, err := http.NewRequest("GET", "/_ping", nil)
+	req, err := http.NewRequest(http.MethodGet, "/_ping", nil)
 	if err != nil {
 		return errors.Wrapf(err, "[%s] could not create new request", d.id)
 	}
@@ -684,7 +684,7 @@ func (d *Daemon) queryRootDir() (string, error) {
 		Transport: clientConfig.transport,
 	}
 
-	req, err := http.NewRequest("GET", "/info", nil)
+	req, err := http.NewRequest(http.MethodGet, "/info", nil)
 	if err != nil {
 		return "", err
 	}

testutil/request/request.go

@@ -115,7 +115,7 @@ func newRequest(endpoint string, opts *Options) (*http.Request, error) {
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed parsing url %q", opts.host)
 	}
-	req, err := http.NewRequest("GET", endpoint, nil)
+	req, err := http.NewRequest(http.MethodGet, endpoint, nil)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to create request")
 	}