feat(BRIDGE-150): Observability service modification; user distinction utility & heartbeat; various observbility metrics & relevant integration tests

internal/services/observability/distinction_utility.go

@@ -0,0 +1,170 @@
+// Copyright (c) 2024 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package observability
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"github.com/ProtonMail/gluon/async"
+	"github.com/ProtonMail/go-proton-api"
+	"github.com/ProtonMail/proton-bridge/v3/internal/updater"
+)
+
+var updateInterval = time.Minute * 5 //nolint:gochecknoglobals
+
+type observabilitySender interface {
+	addMetricsIfClients(metric ...proton.ObservabilityMetric)
+}
+
+// distinctionUtility - used to discern whether X number of events stem from Y number of users.
+type distinctionUtility struct {
+	ctx context.Context
+
+	panicHandler async.PanicHandler
+
+	lastSentMap map[DistinctionErrorTypeEnum]time.Time // Ensures we don't step over the limit of one user update every 5 mins.
+
+	observabilitySender observabilitySender
+	settingsGetter      settingsGetter
+
+	userPlanUnsafe string
+	userPlanLock   sync.Mutex
+
+	heartbeatData     heartbeatData
+	heartbeatDataLock sync.Mutex
+	heartbeatTicker   *time.Ticker
+}
+
+func newDistinctionUtility(ctx context.Context, panicHandler async.PanicHandler, observabilitySender observabilitySender) *distinctionUtility {
+	distinctionUtility := &distinctionUtility{
+		ctx: ctx,
+
+		panicHandler: panicHandler,
+
+		lastSentMap: createLastSentMap(),
+
+		observabilitySender: observabilitySender,
+
+		userPlanUnsafe: planUnknown,
+
+		heartbeatData:   heartbeatData{},
+		heartbeatTicker: time.NewTicker(updateInterval),
+	}
+
+	return distinctionUtility
+}
+
+// sendMetricsWithGuard - schedules the metrics to be sent only if there are authenticated clients.
+func (d *distinctionUtility) sendMetricsWithGuard(metrics ...proton.ObservabilityMetric) {
+	if d.observabilitySender == nil {
+		return
+	}
+
+	d.observabilitySender.addMetricsIfClients(metrics...)
+}
+
+func (d *distinctionUtility) setSettingsGetter(getter settingsGetter) {
+	d.settingsGetter = getter
+}
+
+// checkAndUpdateLastSentMap - checks whether we have sent a relevant user update metric
+// within the last 5 minutes.
+func (d *distinctionUtility) checkAndUpdateLastSentMap(key DistinctionErrorTypeEnum) bool {
+	curTime := time.Now()
+	val, ok := d.lastSentMap[key]
+	if !ok {
+		d.lastSentMap[key] = curTime
+		return true
+	}
+
+	if val.Add(updateInterval).Before(curTime) {
+		d.lastSentMap[key] = curTime
+		return true
+	}
+
+	return false
+}
+
+// generateUserMetric creates the relevant user update metric based on its type
+// and the relevant settings. In the future this will need to be expanded to support multiple
+// versions of the metric if we ever decide to change them.
+func (d *distinctionUtility) generateUserMetric(
+	metricType DistinctionErrorTypeEnum,
+) proton.ObservabilityMetric {
+	schemaName, ok := errorSchemaMap[metricType]
+	if !ok {
+		return proton.ObservabilityMetric{}
+	}
+
+	return generateUserMetric(schemaName, d.getUserPlanSafe(),
+		d.getEmailClientUserAgent(),
+		getEnabled(d.getProxyAllowed()),
+		getEnabled(d.getBetaAccessEnabled()),
+	)
+}
+
+func generateUserMetric(schemaName, plan, mailClient, dohEnabled, betaAccess string) proton.ObservabilityMetric {
+	return proton.ObservabilityMetric{
+		Name:      schemaName,
+		Version:   1,
+		Timestamp: time.Now().Unix(),
+		Data: map[string]interface{}{
+			"Value": 1,
+			"Labels": map[string]string{
+				"plan":              plan,
+				"mailClient":        mailClient,
+				"dohEnabled":        dohEnabled,
+				"betaAccessEnabled": betaAccess,
+			},
+		},
+	}
+}
+
+func (d *distinctionUtility) generateDistinctMetrics(errType DistinctionErrorTypeEnum, metrics ...proton.ObservabilityMetric) []proton.ObservabilityMetric {
+	d.updateHeartbeatData(errType)
+
+	if d.checkAndUpdateLastSentMap(errType) {
+		metrics = append(metrics, d.generateUserMetric(errType))
+	}
+	return metrics
+}
+
+func (d *distinctionUtility) getEmailClientUserAgent() string {
+	ua := ""
+	if d.settingsGetter != nil {
+		ua = d.settingsGetter.GetCurrentUserAgent()
+	}
+
+	return matchUserAgent(ua)
+}
+
+func (d *distinctionUtility) getBetaAccessEnabled() bool {
+	if d.settingsGetter == nil {
+		return false
+	}
+	return d.settingsGetter.GetUpdateChannel() == updater.EarlyChannel
+}
+
+func (d *distinctionUtility) getProxyAllowed() bool {
+	if d.settingsGetter == nil {
+		return false
+	}
+	return d.settingsGetter.GetProxyAllowed()
+}