MM-53023: Add origin client to ObserveAPIEndpointDuration (#23631)

* Add origin device to ObserveAPIEndpointDuration

* Fix generation of einterfaces mocks

* make einterfaces-mocks

* Use request's query and headers to get origin

* Add desktop to the origin device identification

* Test originDevice function

* Rename origin device to origin client

server/channels/web/handlers.go

@@ -407,11 +407,54 @@ func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 		if r.URL.Path != model.APIURLSuffix+"/websocket" {
 			elapsed := float64(time.Since(now)) / float64(time.Second)
-			c.App.Metrics().ObserveAPIEndpointDuration(h.HandlerName, r.Method, statusCode, elapsed)
+			originClient := string(originClient(r))
+			c.App.Metrics().ObserveAPIEndpointDuration(h.HandlerName, r.Method, statusCode, originClient, elapsed)
 		}
 	}
 }
 
+type OriginClient string
+
+const (
+	OriginClientUnknown OriginClient = "unknown"
+	OriginClientWeb     OriginClient = "web"
+	OriginClientMobile  OriginClient = "mobile"
+	OriginClientDesktop OriginClient = "desktop"
+)
+
+// originClient returns the device from which the provided request was issued. The algorithm roughly looks like:
+// - If the URL contains the query mobilev2=true, then it's mobile
+// - If the first field of the user agent starts with either "rnbeta" or "Mattermost", then it's mobile
+// - If the last field of the user agent starts with "Mattermost", then it's desktop
+// - Otherwise, it's web
+func originClient(r *http.Request) OriginClient {
+	userAgent := r.Header.Get("User-Agent")
+	fields := strings.Fields(userAgent)
+	if len(fields) < 1 {
+		return OriginClientUnknown
+	}
+
+	// Is mobile post v2?
+	queryParam := r.URL.Query().Get("mobilev2")
+	if queryParam == "true" {
+		return OriginClientMobile
+	}
+
+	// Is mobile pre v2?
+	clientAgent := fields[0]
+	if strings.HasPrefix(clientAgent, "rnbeta") || strings.HasPrefix(clientAgent, "Mattermost") {
+		return OriginClientMobile
+	}
+
+	// Is desktop?
+	if strings.HasPrefix(fields[len(fields)-1], "Mattermost") {
+		return OriginClientDesktop
+	}
+
+	// Default to web
+	return OriginClientWeb
+}
+
 // checkCSRFToken performs a CSRF check on the provided request with the given CSRF token. Returns whether or not
 // a CSRF check occurred and whether or not it succeeded.
 func (h *Handler) checkCSRFToken(c *Context, r *http.Request, token string, tokenLocation app.TokenLocation, session *model.Session) (checked bool, passed bool) {

server/channels/web/handlers_test.go

@@ -882,3 +882,71 @@ func TestCheckCSRFToken(t *testing.T) {
 		assert.Nil(t, c.Err)
 	})
 }
+
+func TestOriginClient(t *testing.T) {
+	testCases := []struct {
+		name           string
+		userAgent      string
+		mobilev2       bool
+		expectedClient OriginClient
+	}{
+		{
+			name:           "No user agent - unknown client",
+			userAgent:      "",
+			expectedClient: OriginClientUnknown,
+		},
+		{
+			name:           "Mozilla user agent",
+			userAgent:      "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/118.0",
+			expectedClient: OriginClientWeb,
+		},
+		{
+			name:           "Chrome user agent",
+			userAgent:      "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36",
+			expectedClient: OriginClientWeb,
+		},
+		{
+			name:           "Mobile post v2",
+			userAgent:      "someother-agent/3.2.4",
+			mobilev2:       true,
+			expectedClient: OriginClientMobile,
+		},
+		{
+			name:           "Mobile Android",
+			userAgent:      "rnbeta/2.0.0.441 someother-agent/3.2.4",
+			expectedClient: OriginClientMobile,
+		},
+		{
+			name:           "Mobile iOS",
+			userAgent:      "Mattermost/2.0.0.441 someother-agent/3.2.4",
+			expectedClient: OriginClientMobile,
+		},
+		{
+			name:           "Desktop user agent",
+			userAgent:      "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.5481.177 Electron/23.1.2 Safari/537.36 Mattermost/5.3.1",
+			expectedClient: OriginClientDesktop,
+		},
+	}
+
+	for _, tc := range testCases {
+		req, err := http.NewRequest(http.MethodGet, "example.com", nil)
+		require.NoError(t, err)
+
+		// Set User-Agent header, if any
+		if tc.userAgent != "" {
+			req.Header.Set("User-Agent", tc.userAgent)
+		}
+
+		// Set mobilev2 query if needed
+		if tc.mobilev2 {
+			q := req.URL.Query()
+			q.Add("mobilev2", "true")
+			req.URL.RawQuery = q.Encode()
+		}
+
+		// Compute origin client
+		actualClient := originClient(req)
+
+		require.Equal(t, tc.expectedClient, actualClient)
+	}
+}

server/einterfaces/metrics.go

@@ -58,7 +58,7 @@ type MetricsInterface interface {
 	IncrementFilesSearchCounter()
 	ObserveFilesSearchDuration(elapsed float64)
 	ObserveStoreMethodDuration(method, success string, elapsed float64)
-	ObserveAPIEndpointDuration(endpoint, method, statusCode string, elapsed float64)
+	ObserveAPIEndpointDuration(endpoint, method, statusCode, originClient string, elapsed float64)
 	IncrementPostIndexCounter()
 	IncrementFileIndexCounter()
 	IncrementUserIndexCounter()

server/einterfaces/mocks/MetricsInterface.go

@@ -239,9 +239,9 @@ func (_m *MetricsInterface) IncrementWebsocketReconnectEvent(eventType string) {
 	_m.Called(eventType)
 }
 
-// ObserveAPIEndpointDuration provides a mock function with given fields: endpoint, method, statusCode, elapsed
-func (_m *MetricsInterface) ObserveAPIEndpointDuration(endpoint string, method string, statusCode string, elapsed float64) {
-	_m.Called(endpoint, method, statusCode, elapsed)
+// ObserveAPIEndpointDuration provides a mock function with given fields: endpoint, method, statusCode, originClient, elapsed
+func (_m *MetricsInterface) ObserveAPIEndpointDuration(endpoint string, method string, statusCode string, originClient string, elapsed float64) {
+	_m.Called(endpoint, method, statusCode, originClient, elapsed)
 }
 
 // ObserveClusterRequestDuration provides a mock function with given fields: elapsed