feat(receivers): config to skip alerts with duplicated receivers

cmd/karma/tests/testscript/059_log_full_config_env.txt

@@ -224,6 +224,7 @@ level=info msg="    - keep2"
 level=info msg="  strip:"
 level=info msg="    - strip1"
 level=info msg="    - strip2"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 1s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/060_log_full_config_file.txt

@@ -260,6 +260,7 @@ level=info msg="    - keep2"
 level=info msg="  strip:"
 level=info msg="    - strip1"
 level=info msg="    - strip2"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 5m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/065_proxy-with-readonly.txt

@@ -114,6 +114,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/066_proxy.txt

@@ -114,6 +114,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/067_readonly.txt

@@ -114,6 +114,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/070_upper_case_keys.txt

@@ -124,6 +124,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/097_proxy_url_config.txt

@@ -114,6 +114,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

cmd/karma/tests/testscript/112_flag_defaultAlertmanagers.txt

@@ -93,6 +93,7 @@ level=info msg="  timestamp: false"
 level=info msg="receivers:"
 level=info msg="  keep: []"
 level=info msg="  strip: []"
+level=info msg="  stripIfDuplicated: []"
 level=info msg="silences:"
 level=info msg="  expired: 10m0s"
 level=info msg="  comments:"

docs/CONFIGURATION.md

@@ -1211,18 +1211,22 @@ silences:
 
 `receivers` section allows configuring how alerts from different receivers are
 handled by karma. If alerts are routed to multiple receivers they can be
-duplicated in the UI, each instance will have different value for `@receiver`.
+duplicated in the UI unless the receiver is listed in `stripIfDuplicated`. Each
+instance will have different value for `@receiver`.
 Syntax:
 
 ```YAML
 receivers:
   keep: list of strings
   strip: list of strings
+  stripIfDuplicated: list of strings
 ```
 
 - `keep` - list of receivers name that are allowed, if empty all receivers are
   allowed.
 - `strip` - list of receiver names that will not be shown in the UI.
+- `stripIfDuplicated` - list of receiver names to consider when hiding
+  duplicated alerts.
 
 Example where alerts that are routed to the `alertmanage2es` receiver are
 ignored by karma.

docs/example.yaml

@@ -59,6 +59,7 @@ silences:
 receivers:
   keep: []
   strip: []
+  stripIfDuplicated: []
 silenceForm:
   strip:
     labels:

internal/alertmanager/dedup.go

@@ -28,6 +28,25 @@
 		}
 	}
 
+	// map of alerts fingerprints to list of receivers, taking into account strip/keep configuration
+	receiversMap := map[string][]string{}
+	for _, agList := range uniqueGroups {
+		for _, ag := range agList {
+			for _, alert := range ag.Alerts {
+				lfp := alert.LabelsFingerprint()
+				a, found := receiversMap[lfp]
+				if transform.StripReceivers(config.Config.Receivers.Keep, config.Config.Receivers.Strip, alert.Receiver) {
+					continue
+				}
+				if found && !slices.StringInSlice(a, alert.Receiver) {
+					receiversMap[lfp] = append(a, alert.Receiver)
+				} else {
+					receiversMap[lfp] = []string{alert.Receiver}
+				}
+			}
+		}
+	}
+
 	dedupedGroups := []models.AlertGroup{}
 	alertStates := map[string][]string{}
 	for _, agList := range uniqueGroups {
@@ -41,6 +60,15 @@
 					continue
 				}
 
+				// skip alert if its receiver is duplicated
+				d, receiverFound := receiversMap[alert.LabelsFingerprint()]
+				if receiverFound {
+					if slices.StringInSlice(config.Config.Receivers.StripIfDuplicated, alert.Receiver) && len(d) > 1 {
+						log.Debug().Str("fingerprint", alert.Fingerprint).Strs("receivers", d).Msg("Skipping alert with duplicated receiver")
+						continue
+					}
+				}
+
 				keep := true
 				for _, am := range upstreams {
 					if !am.healthchecksVisible {

internal/config/config.go

@@ -128,6 +128,8 @@ func SetupFlags(f *pflag.FlagSet) {
 		"List of receivers to keep, all alerts with different receivers will be ignored")
 	f.StringSlice("receivers.strip", []string{},
 		"List of receivers to not display alerts for")
+	f.StringSlice("receivers.stripIfDuplicated", []string{},
+		"List of receivers to not display alerts for if they are duplicated for the same alert")
 
 	f.Duration("silences.expired", time.Minute*10, "Maximum age of expired silences to show on active alerts")
 	f.StringSlice("silenceForm.strip.labels", []string{}, "List of labels to ignore when auto-filling silence form from alerts")

internal/config/config_test.go

@@ -143,6 +143,7 @@ log:
 receivers:
   keep: []
   strip: []
+  stripIfDuplicated: []
 silences:
   expired: 10m0s
   comments:
@@ -395,6 +396,7 @@ func TestDefaultConfig(t *testing.T) {
 	expectedConfig.Grid.Auto.Order = []string{}
 	expectedConfig.Receivers.Keep = []string{}
 	expectedConfig.Receivers.Strip = []string{}
+	expectedConfig.Receivers.StripIfDuplicated = []string{}
 	expectedConfig.SilenceForm.Strip.Labels = []string{}
 	expectedConfig.SilenceForm.DefaultAlertmanagers = []string{}
 

internal/config/models.go

@@ -195,8 +195,9 @@ type configSchema struct {
 		Timestamp bool
 	}
 	Receivers struct {
-		Keep  []string
-		Strip []string
+		Keep              []string
+		Strip             []string
+		StripIfDuplicated []string `yaml:"stripIfDuplicated" koanf:"stripIfDuplicated"`
 	}
 	Silences struct {
 		Expired  time.Duration