Add mobile metrics (#27045)

* Add mobile metrics

* Fix mocks

* Add tests

* Fix lint

* Address feedback

* Fix lint

* Fix test

* Fix CI

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/enterprise/metrics/metrics.go

@@ -42,6 +42,7 @@ const (
 	MetricsSubsystemSystem             = "system"
 	MetricsSubsystemJobs               = "jobs"
 	MetricsSubsystemNotifications      = "notifications"
+	MetricsSubsystemClientsMobileApp   = "mobileapp"
 	MetricsSubsystemClientsWeb         = "webapp"
 	MetricsCloudInstallationLabel      = "installationId"
 	MetricsCloudDatabaseClusterLabel   = "databaseClusterName"
@@ -222,6 +223,10 @@ type MetricsInterfaceImpl struct {
 	ClientTeamSwitchDuration        *prometheus.HistogramVec
 	ClientRHSLoadDuration           *prometheus.HistogramVec
 	ClientGlobalThreadsLoadDuration *prometheus.HistogramVec
+
+	MobileClientLoadDuration          *prometheus.HistogramVec
+	MobileClientChannelSwitchDuration *prometheus.HistogramVec
+	MobileClientTeamSwitchDuration    *prometheus.HistogramVec
 }
 
 func init() {
@@ -1262,6 +1267,42 @@ func New(ps *platform.PlatformService, driver, dataSource string) *MetricsInterf
 	)
 	m.Registry.MustRegister(m.ClientGlobalThreadsLoadDuration)
 
+	m.MobileClientLoadDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: MetricsNamespace,
+			Subsystem: MetricsSubsystemClientsMobileApp,
+			Name:      "mobile_load",
+			Help:      "Duration of the time taken from when a user opens the app and the app finally loads all relevant information (seconds)",
+			Buckets:   []float64{1, 1.5, 2, 3, 4, 4.5, 5, 5.5, 6, 7.5, 10, 20, 25, 30},
+		},
+		[]string{"platform"},
+	)
+	m.Registry.MustRegister(m.MobileClientLoadDuration)
+
+	m.MobileClientChannelSwitchDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: MetricsNamespace,
+			Subsystem: MetricsSubsystemClientsMobileApp,
+			Name:      "mobile_channel_switch",
+			Help:      "Duration of the time taken from when a user clicks on a channel name, and the full channel sreen is loaded (seconds)",
+			Buckets:   []float64{0.150, 0.200, 0.300, 0.400, 0.450, 0.500, 0.550, 0.600, 0.750, 1, 2, 3},
+		},
+		[]string{"platform"},
+	)
+	m.Registry.MustRegister(m.MobileClientChannelSwitchDuration)
+
+	m.MobileClientTeamSwitchDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: MetricsNamespace,
+			Subsystem: MetricsSubsystemClientsMobileApp,
+			Name:      "mobile_team_switch",
+			Help:      "Duration of the time taken from when a user clicks on a team, and the full categories screen is loaded (seconds)",
+			Buckets:   []float64{0.150, 0.200, 0.250, 0.300, 0.350, 0.400, 0.500, 0.750, 1, 2, 3},
+		},
+		[]string{"platform"},
+	)
+	m.Registry.MustRegister(m.MobileClientTeamSwitchDuration)
+
 	return m
 }
 
@@ -1764,6 +1805,18 @@ func (mi *MetricsInterfaceImpl) ObserveGlobalThreadsLoadDuration(platform, agent
 	mi.ClientGlobalThreadsLoadDuration.With(prometheus.Labels{"platform": platform, "agent": agent}).Observe(elapsed)
 }
 
+func (mi *MetricsInterfaceImpl) ObserveMobileClientLoadDuration(platform string, elapsed float64) {
+	mi.MobileClientLoadDuration.With(prometheus.Labels{"platform": platform}).Observe(elapsed)
+}
+
+func (mi *MetricsInterfaceImpl) ObserveMobileClientChannelSwitchDuration(platform string, elapsed float64) {
+	mi.MobileClientChannelSwitchDuration.With(prometheus.Labels{"platform": platform}).Observe(elapsed)
+}
+
+func (mi *MetricsInterfaceImpl) ObserveMobileClientTeamSwitchDuration(platform string, elapsed float64) {
+	mi.MobileClientTeamSwitchDuration.With(prometheus.Labels{"platform": platform}).Observe(elapsed)
+}
+
 func extractDBCluster(driver, connectionString string) (string, error) {
 	host, err := extractHost(driver, connectionString)
 	if err != nil {

server/enterprise/metrics/metrics_test.go

@@ -176,6 +176,61 @@ func TestPluginMetrics(t *testing.T) {
 	})
 }
 
+func TestMobileMetrics(t *testing.T) {
+	th := api4.SetupEnterprise(t, app.StartMetrics)
+	defer th.TearDown()
+
+	configureMetrics(th)
+	mi := th.App.Metrics()
+
+	miImpl, ok := mi.(*MetricsInterfaceImpl)
+	require.True(t, ok, fmt.Sprintf("App.Metrics is not *MetricsInterfaceImpl, but %T", mi))
+
+	ttcc := []struct {
+		name         string
+		histogramVec *prometheus.HistogramVec
+		observeFunc  func(string, float64)
+	}{
+		{
+			name:         "load duration",
+			histogramVec: miImpl.MobileClientLoadDuration,
+			observeFunc:  mi.ObserveMobileClientLoadDuration,
+		},
+		{
+			name:         "channel switch duration",
+			histogramVec: miImpl.MobileClientChannelSwitchDuration,
+			observeFunc:  mi.ObserveMobileClientChannelSwitchDuration,
+		},
+		{
+			name:         "team switch duration",
+			histogramVec: miImpl.MobileClientTeamSwitchDuration,
+			observeFunc:  mi.ObserveMobileClientTeamSwitchDuration,
+		},
+	}
+
+	for _, tc := range ttcc {
+		t.Run(tc.name, func(t *testing.T) {
+			m := &prometheusModels.Metric{}
+			elapsed := 999.1
+
+			for _, platform := range []string{"ios", "android"} {
+				actualMetric, err := tc.histogramVec.GetMetricWith(prometheus.Labels{"platform": platform})
+				require.NoError(t, err)
+				require.NoError(t, actualMetric.(prometheus.Histogram).Write(m))
+				require.Equal(t, uint64(0), m.Histogram.GetSampleCount())
+				require.Equal(t, 0.0, m.Histogram.GetSampleSum())
+
+				tc.observeFunc(platform, elapsed)
+				actualMetric, err = tc.histogramVec.GetMetricWith(prometheus.Labels{"platform": platform})
+				require.NoError(t, err)
+				require.NoError(t, actualMetric.(prometheus.Histogram).Write(m))
+				require.Equal(t, uint64(1), m.Histogram.GetSampleCount())
+				require.InDelta(t, elapsed, m.Histogram.GetSampleSum(), 0.001)
+			}
+		})
+	}
+}
+
 func TestExtractDBCluster(t *testing.T) {
 	testCases := []struct {
 		description         string