Alerting: Support for Mimir configuration in Grafana Alertmanager (#106402)

pkg/services/ngalert/notifier/alertmanager.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"strconv"
+	"strings"
 	"time"
 
 	alertingNotify "github.com/grafana/alerting/notify"
@@ -314,11 +315,43 @@ func (am *alertmanager) aggregateInhibitMatchers(rules []config.InhibitRule, amu
 	}
 }
 
+func logMergeResult(l log.Logger, m apimodels.MergeResult) {
+	if len(m.RenamedReceivers) == 0 && len(m.RenamedTimeIntervals) == 0 {
+		return
+	}
+
+	logCtx := make([]any, 0, 4)
+	if len(m.RenamedTimeIntervals) > 0 {
+		rcvBuilder := strings.Builder{}
+		for from, to := range m.RenamedReceivers {
+			rcvBuilder.WriteString(fmt.Sprintf("'%s'->'%s',", from, to))
+		}
+		logCtx = append(logCtx, "renamedReceivers", fmt.Sprintf("[%s]", rcvBuilder.String()[0:rcvBuilder.Len()-1]))
+	}
+	if len(m.RenamedTimeIntervals) > 0 {
+		rcvBuilder := strings.Builder{}
+		for from, to := range m.RenamedTimeIntervals {
+			rcvBuilder.WriteString(fmt.Sprintf("'%s'->'%s',", from, to))
+		}
+		logCtx = append(logCtx, "renamedTimeIntervals", fmt.Sprintf("[%s]", rcvBuilder.String()[0:rcvBuilder.Len()-1]))
+	}
+	l.Info("Configurations merged successfully but some resources were renamed", logCtx...)
+}
+
 // applyConfig applies a new configuration by re-initializing all components using the configuration provided.
 // It returns a boolean indicating whether the user config was changed and an error.
 // It is not safe to call concurrently.
 func (am *alertmanager) applyConfig(ctx context.Context, cfg *apimodels.PostableUserConfig, skipInvalid bool) (bool, error) {
-	err := AddAutogenConfig(ctx, am.logger, am.Store, am.Base.TenantID(), &cfg.AlertmanagerConfig, skipInvalid)
+	mergeResult, err := cfg.GetMergedAlertmanagerConfig()
+	if err != nil {
+		return false, fmt.Errorf("failed to get full alertmanager configuration: %w", err)
+	}
+	logMergeResult(am.logger, mergeResult)
+	amConfig := mergeResult.Config
+	templates := cfg.GetMergedTemplateDefinitions()
+
+	// Now add autogenerated config to the route.
+	err = AddAutogenConfig(ctx, am.logger, am.Store, am.Base.TenantID(), &amConfig, skipInvalid)
 	if err != nil {
 		return false, err
 	}
@@ -337,7 +370,7 @@ func (am *alertmanager) applyConfig(ctx context.Context, cfg *apimodels.Postable
 		return false, nil
 	}
 
-	receivers := PostableApiAlertingConfigToApiReceivers(cfg.AlertmanagerConfig)
+	receivers := PostableApiAlertingConfigToApiReceivers(amConfig)
 	for _, recv := range receivers {
 		err = patchNewSecureFields(ctx, recv, alertingNotify.DecodeSecretsFromBase64, am.decryptFn)
 		if err != nil {
@@ -347,11 +380,11 @@ func (am *alertmanager) applyConfig(ctx context.Context, cfg *apimodels.Postable
 
 	am.logger.Info("Applying new configuration to Alertmanager", "configHash", fmt.Sprintf("%x", configHash))
 	err = am.Base.ApplyConfig(alertingNotify.NotificationsConfiguration{
-		RoutingTree:       cfg.AlertmanagerConfig.Route.AsAMRoute(),
-		InhibitRules:      cfg.AlertmanagerConfig.InhibitRules,
-		MuteTimeIntervals: cfg.AlertmanagerConfig.MuteTimeIntervals,
-		TimeIntervals:     cfg.AlertmanagerConfig.TimeIntervals,
-		Templates:         ToTemplateDefinitions(cfg),
+		RoutingTree:       amConfig.Route.AsAMRoute(),
+		InhibitRules:      amConfig.InhibitRules,
+		MuteTimeIntervals: amConfig.MuteTimeIntervals,
+		TimeIntervals:     amConfig.TimeIntervals,
+		Templates:         templates,
 		Receivers:         receivers,
 		DispatcherLimits:  &nilLimits{},
 		Raw:               rawConfig,