fix(api): better support for @alertmanager & @cluster filters

cmd/karma/views.go

@@ -245,6 +245,25 @@ func alerts(c *gin.Context) {
 			if !validFilters || (slices.BoolInSlice(results, true) && !slices.BoolInSlice(results, false)) {
 				matches++
 
+				blockedAMs := map[string]bool{}
+				for _, am := range alert.Alertmanager {
+					for _, filter := range matchFilters {
+						if filter.GetIsValid() && filter.GetIsAlertmanagerFilter() && !filter.MatchAlertmanager(&am) {
+							blockedAMs[am.Name] = true
+						}
+					}
+				}
+				if len(blockedAMs) > 0 {
+					ams := []models.AlertmanagerInstance{}
+					for _, am := range alert.Alertmanager {
+						_, found := blockedAMs[am.Name]
+						if !found {
+							ams = append(ams, am)
+						}
+					}
+					alert.Alertmanager = ams
+				}
+
 				alertGridLabelValues := map[string]bool{}
 				switch gridLabel {
 				case "@receiver":

internal/filters/filter.go

@@ -12,22 +12,25 @@ import (
 type FilterT interface {
 	init(name string, matcher *matcherT, rawText string, isValid bool, value string)
 	Match(alert *models.Alert, matches int) bool
+	MatchAlertmanager(am *models.AlertmanagerInstance) bool
 	GetRawText() string
 	GetHits() int
 	GetIsValid() bool
 	GetName() string
 	GetMatcher() string
 	GetValue() string
+	GetIsAlertmanagerFilter() bool
 }
 
 type alertFilter struct {
 	FilterT
-	Matched string
-	Matcher matcherT
-	RawText string
-	Value   interface{}
-	IsValid bool
-	Hits    int
+	Matched              string
+	Matcher              matcherT
+	RawText              string
+	Value                interface{}
+	IsValid              bool
+	Hits                 int
+	IsAlertmanagerFilter bool
 }
 
 func (filter *alertFilter) init(name string, matcher *matcherT, rawText string, isValid bool, value string) {
@@ -67,6 +70,10 @@ func (filter *alertFilter) GetValue() string {
 	return fmt.Sprintf("%s", filter.Value)
 }
 
+func (filter *alertFilter) GetIsAlertmanagerFilter() bool {
+	return filter.IsAlertmanagerFilter
+}
+
 type newFilterFactory func() FilterT
 
 // NewFilter creates new filter object from filter expression like "key=value"

internal/filters/filter_alertmanager.go

@@ -28,8 +28,17 @@ func (filter *alertmanagerInstanceFilter) Match(alert *models.Alert, matches int
 	panic(e)
 }
 
+func (filter *alertmanagerInstanceFilter) MatchAlertmanager(am *models.AlertmanagerInstance) bool {
+	if filter.IsValid {
+		return filter.Matcher.Compare(am.Name, filter.Value)
+	}
+	e := fmt.Sprintf("MatchAlertmanager() called on invalid filter %#v", filter)
+	panic(e)
+}
+
 func newAlertmanagerInstanceFilter() FilterT {
 	f := alertmanagerInstanceFilter{}
+	f.IsAlertmanagerFilter = true
 	return &f
 }
 

internal/filters/filter_cluster.go

@@ -28,8 +28,17 @@ func (filter *alertmanagerClusterFilter) Match(alert *models.Alert, matches int)
 	panic(e)
 }
 
+func (filter *alertmanagerClusterFilter) MatchAlertmanager(am *models.AlertmanagerInstance) bool {
+	if filter.IsValid {
+		return filter.Matcher.Compare(am.Cluster, filter.Value)
+	}
+	e := fmt.Sprintf("MatchAlertmanager() called on invalid filter %#v", filter)
+	panic(e)
+}
+
 func newAlertmanagerClusterFilter() FilterT {
 	f := alertmanagerClusterFilter{}
+	f.IsAlertmanagerFilter = true
 	return &f
 }