Add --receivers.keep for consistency with other options

there's --labels.keep so same should apply to receivers, add new option, tests and fixes as it wasn't working properly

docs/CONFIGURATION.md

@@ -355,19 +355,19 @@ jira: []
 ### Receivers
 
 `receivers` section allows configuring how alerts from different receivers are
-handled by unsee.
+handled by unsee. If alerts are routed to multiple receivers they can be
+duplicated in the UI, each instance will have different value for `@receiver`.
 Syntax:
 
 ```yaml
 receivers:
+  keep: list of strings
   strip: list of strings
 ```
 
-* `strip` - list of receiver names that should be ignored when collecting data
-  from Alertmanager API. If alerts are routed to multiple receivers they can be
-  duplicated in the UI, each instance will have different value for `@receiver`.
-  This options allows to set a list of receivers that will not be shown in the
-  UI.
+* `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.
 
 Example where alerts that are routed to the `alertmanage2es` receiver are
 ignored by unsee.
@@ -433,3 +433,10 @@ Exaceptions:
 Environment variables are mapped in a similiar way as command line flags,
 `alertmanager:interval` is accessible as `ALERTMANAGER_INTERVAL` env.
 Same exceptions apply as with command line flags.
+
+* `HOST` - used by gin webserver, same effect as setting `listen:address` config
+  option
+* `PORT` - used by gin webserver, same effect as setting `listen:port` config
+  option
+* `SENTRY_DSN` - is used by Sentry itself, same effect as passing value to
+  `sentry:private` config option.

internal/alertmanager/dedup.go

@@ -31,6 +31,11 @@ func DedupAlerts() []models.AlertGroup {
 		alerts := map[string]models.Alert{}
 		for _, ag := range agList {
 			for _, alert := range ag.Alerts {
+				// remove all alerts for receiver(s) that the user doesn't
+				// want to see in the UI
+				if transform.StripReceivers(config.Config.Receivers.Keep, config.Config.Receivers.Strip, alert.Receiver) {
+					continue
+				}
 				alertLFP := alert.LabelsFingerprint()
 				a, found := alerts[alertLFP]
 				if found {
@@ -60,14 +65,13 @@ func DedupAlerts() []models.AlertGroup {
 				}
 			}
 		}
+		// skip empty groups
+		if len(alerts) == 0 {
+			continue
+		}
 		ag := models.AlertGroup(agList[0])
 		ag.Alerts = models.AlertList{}
 		for _, alert := range alerts {
-			// remove all alerts for receiver(s) that the user doesn't
-			// want to see in the UI
-			if transform.StripReceivers(config.Config.Receivers.Strip, alert.Receiver) {
-				continue
-			}
 			// strip labels user doesn't want to see in the UI
 			alert.Labels = transform.StripLables(config.Config.Labels.Keep, config.Config.Labels.Strip, alert.Labels)
 			// calculate final alert state based on the most important value found

internal/alertmanager/dedup_test.go

@@ -99,3 +99,16 @@ func TestDedupColors(t *testing.T) {
 		t.Errorf("Expected %d color keys, got %d", expected, len(colors))
 	}
 }
+
+func TestStripReceivers(t *testing.T) {
+	os.Setenv("RECEIVERS_STRIP", "by-name by-cluster-service")
+	os.Setenv("ALERTMANAGER_URI", "http://localhost")
+	config.Config.Read()
+	if err := pullAlerts(); err != nil {
+		t.Error(err)
+	}
+	alerts := alertmanager.DedupAlerts()
+	if len(alerts) > 0 {
+		t.Errorf("Expected no alerts after stripping all receivers, got %d", len(alerts))
+	}
+}

internal/config/config.go

@@ -58,6 +58,8 @@ func init() {
 	pflag.String("log.level", "info",
 		"Log level, one of: debug, info, warning, error, fatal and panic")
 
+	pflag.StringSlice("receivers.keep", []string{},
+		"List of receivers to keep, all alerts with different receivers will be ignored")
 	pflag.StringSlice("receivers.strip", []string{},
 		"List of receivers to not display alerts for")
 
@@ -121,6 +123,7 @@ func (config *configSchema) Read() {
 	config.Listen.Prefix = v.GetString("listen.prefix")
 	config.Log.Config = v.GetBool("log.config")
 	config.Log.Level = v.GetString("log.level")
+	config.Receivers.Keep = v.GetStringSlice("receivers.keep")
 	config.Receivers.Strip = v.GetStringSlice("receivers.strip")
 	config.Sentry.Private = v.GetString("sentry.private")
 	config.Sentry.Public = v.GetString("sentry.public")

internal/config/models.go

@@ -36,8 +36,8 @@ type configSchema struct {
 		Default []string
 	}
 	Labels struct {
-		Strip []string
 		Keep  []string
+		Strip []string
 	}
 	Listen struct {
 		Address string
@@ -50,6 +50,7 @@ type configSchema struct {
 	}
 	JIRA      []jiraRule
 	Receivers struct {
+		Keep  []string
 		Strip []string
 	}
 	Sentry struct {

internal/transform/strip.go

@@ -28,11 +28,16 @@ func StripLables(keptLabels, ignoredLabels []string, sourceLabels map[string]str
 }
 
 // StripReceivers allows filtering all alerts for specified receiver(s)
-func StripReceivers(ignoredReceivers []string, alertReceiver string) bool {
-	for _, ignoredReceiver := range ignoredReceivers {
-		if alertReceiver == ignoredReceiver {
-			return true
-		}
+// it will return true if alert uses receiver that should be stripped
+func StripReceivers(keptReceivers, ignoredReceivers []string, alertReceiver string) bool {
+	// true if we keep by default
+	keepAll := len(keptReceivers) == 0
+	// is this receiver on the whitelist ?
+	inKeep := slices.StringInSlice(keptReceivers, alertReceiver)
+	// is this receiver on the blacklist ?
+	inStrip := slices.StringInSlice(ignoredReceivers, alertReceiver)
+	if (keepAll || inKeep) && !inStrip {
+		return false
 	}
-	return false
+	return true
 }

internal/transform/strip_test.go

@@ -7,15 +7,15 @@ import (
 	"github.com/cloudflare/unsee/internal/transform"
 )
 
-type stripTest struct {
+type stripLabelTest struct {
 	strip  []string
 	keep   []string
 	before map[string]string
 	after  map[string]string
 }
 
-var stripTests = []stripTest{
-	stripTest{
+var stripLabelTests = []stripLabelTest{
+	stripLabelTest{
 		strip: []string{"env"},
 		keep:  []string{},
 		before: map[string]string{
@@ -28,7 +28,7 @@ var stripTests = []stripTest{
 			"level": "info",
 		},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{"server"},
 		keep:  []string{},
 		before: map[string]string{
@@ -42,7 +42,7 @@ var stripTests = []stripTest{
 			"level": "info",
 		},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{},
 		keep:  []string{},
 		before: map[string]string{
@@ -56,7 +56,7 @@ var stripTests = []stripTest{
 			"level": "info",
 		},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{"host"},
 		keep:  []string{},
 		before: map[string]string{
@@ -64,7 +64,7 @@ var stripTests = []stripTest{
 		},
 		after: map[string]string{},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{},
 		keep:  []string{"env"},
 		before: map[string]string{
@@ -76,7 +76,7 @@ var stripTests = []stripTest{
 			"env": "production",
 		},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{"env"},
 		keep:  []string{"host"},
 		before: map[string]string{
@@ -88,7 +88,7 @@ var stripTests = []stripTest{
 			"host": "localhost",
 		},
 	},
-	stripTest{
+	stripLabelTest{
 		strip: []string{},
 		keep:  []string{"env"},
 		before: map[string]string{
@@ -100,10 +100,65 @@ var stripTests = []stripTest{
 }
 
 func TestStripLables(t *testing.T) {
-	for _, testCase := range stripTests {
+	for _, testCase := range stripLabelTests {
 		labels := transform.StripLables(testCase.keep, testCase.strip, testCase.before)
 		if !reflect.DeepEqual(labels, testCase.after) {
 			t.Errorf("StripLables failed, expected %v, got %v", testCase.after, labels)
 		}
 	}
 }
+
+type stripReceiverTest struct {
+	strip    []string
+	keep     []string
+	receiver string
+	stripped bool
+}
+
+var stripReceiverTests = []stripReceiverTest{
+	stripReceiverTest{
+		strip:    []string{},
+		keep:     []string{},
+		receiver: "default",
+		stripped: false,
+	},
+	stripReceiverTest{
+		strip:    []string{"default"},
+		keep:     []string{},
+		receiver: "default",
+		stripped: true,
+	},
+	stripReceiverTest{
+		strip:    []string{"default"},
+		keep:     []string{"default"},
+		receiver: "default",
+		stripped: true,
+	},
+	stripReceiverTest{
+		strip:    []string{},
+		keep:     []string{"default"},
+		receiver: "default",
+		stripped: false,
+	},
+	stripReceiverTest{
+		strip:    []string{"foo", "bar"},
+		keep:     []string{},
+		receiver: "default",
+		stripped: false,
+	},
+	stripReceiverTest{
+		strip:    []string{"foo", "default"},
+		keep:     []string{"foo", "bar"},
+		receiver: "default",
+		stripped: true,
+	},
+}
+
+func TestStripReceivers(t *testing.T) {
+	for _, testCase := range stripReceiverTests {
+		stripped := transform.StripReceivers(testCase.keep, testCase.strip, testCase.receiver)
+		if stripped != testCase.stripped {
+			t.Errorf("StripReceivers failed, expected %v, got %v", testCase.stripped, stripped)
+		}
+	}
+}