support services without prefixes

README.md

@@ -104,7 +104,7 @@ Each service under this section can have the following settings:
 | timeout      | Time in which the check command should complete. Afterwards it will be handled as if the check command failed. Defaults to **10s**, format following that of [`time.ParseDuration`](https://pkg.go.dev/time#ParseDuration).              |
 | fail         | The amount of times the check command should fail before the service is considered to be down. Defaults to **1**                                                                                                                         |
 | rise         | The amount of times the check command should succeed before the service is considered to be up. Defaults to **1**                                                                                                                        |
-| prefixes     | Array of prefixes, mixed IPv4 and IPv6. At least 1 prefix is **required** per service                                                                                                                                                    |
+| prefixes     | Array of prefixes, mixed IPv4 and IPv6. When no prefixes are given, the resulting filter won't match any addresses but just return **true** or **false**.                                                                                |
 
 ## **[prometheus]**
 

birdwatcher/bird.go

@@ -52,7 +52,9 @@ func writeBirdConfig(filename string, prefixes PrefixCollection, compatBird213 b
 		return err
 	}
 
-	tmpl := template.Must(template.New("func").Funcs(tplFuncs).Parse(functionsTemplate))
+	tmpl := template.Must(template.New("func").
+		Funcs(tplFuncs).
+		Parse(functionsTemplate))
 
 	tplBody := struct {
 		Collections   PrefixCollection
@@ -63,7 +65,7 @@ func writeBirdConfig(filename string, prefixes PrefixCollection, compatBird213 b
 	}
 
 	var buf bytes.Buffer
-	if err := tmpl.Execute(&buf, tplBody); err != nil {
+	if err = tmpl.Execute(&buf, tplBody); err != nil {
 		return err
 	}
 

birdwatcher/bird_test.go

@@ -13,26 +13,40 @@ import (
 func TestWriteBirdConfig(t *testing.T) {
 	t.Parallel()
 
-	t.Run("empty config", func(t *testing.T) {
+	t.Run("filter down", func(t *testing.T) {
 		t.Parallel()
 
 		// open tempfile
 		tmpFile, err := os.CreateTemp(t.TempDir(), "bird_test")
 		require.NoError(t, err)
 		defer os.Remove(tmpFile.Name())
 
+		// no prefixes, service unhealthy
 		prefixes := make(PrefixCollection)
-		prefixes["match_route"] = NewPrefixSet("match_route")
+		prefixes["match_route"] = NewPrefixSet(&ServiceCheck{FunctionName: "match_route"})
 
-		// write bird config with empty prefix list
+		// write bird config with empty prefix list and unhealthy
 		err = writeBirdConfig(tmpFile.Name(), prefixes, false)
 		require.NoError(t, err)
 
 		// read data from temp file and compare it to file fixture
 		data, err := os.ReadFile(tmpFile.Name())
 		require.NoError(t, err)
 
-		fixture, err := os.ReadFile("testdata/bird/config_empty")
+		fixture, err := os.ReadFile("testdata/bird/filter_down")
+		require.NoError(t, err)
+
+		assert.Equal(t, string(fixture), string(data))
+
+		// switch to compat mode and do it again
+		err = writeBirdConfig(tmpFile.Name(), prefixes, true)
+		require.NoError(t, err)
+
+		// read data from temp file and compare it to file fixture
+		data, err = os.ReadFile(tmpFile.Name())
+		require.NoError(t, err)
+
+		fixture, err = os.ReadFile("testdata/bird/filter_down_compat")
 		require.NoError(t, err)
 
 		assert.Equal(t, string(fixture), string(data))
@@ -46,8 +60,9 @@ func TestWriteBirdConfig(t *testing.T) {
 		require.NoError(t, err)
 		defer os.Remove(tmpFile.Name())
 
+		// one healthy prefix, service assumed healthy
 		prefixes := make(PrefixCollection)
-		prefixes["match_route"] = NewPrefixSet("match_route")
+		prefixes["match_route"] = NewPrefixSet(&ServiceCheck{FunctionName: "match_route"})
 
 		for _, pref := range []string{"1.2.3.4/32", "2.3.4.5/26", "3.4.5.6/24", "4.5.6.7/21"} {
 			_, prf, _ := net.ParseCIDR(pref)
@@ -62,37 +77,64 @@ func TestWriteBirdConfig(t *testing.T) {
 		data, err := os.ReadFile(tmpFile.Name())
 		require.NoError(t, err)
 
-		fixture, err := os.ReadFile("testdata/bird/config")
+		fixture, err := os.ReadFile("testdata/bird/filter_one_prefix")
+		require.NoError(t, err)
+
+		assert.Equal(t, string(fixture), string(data))
+
+		// switch to compat mode and do it again
+		// write bird config to it
+		err = writeBirdConfig(tmpFile.Name(), prefixes, true)
+		require.NoError(t, err)
+
+		// read data from temp file and compare it to file fixture
+		data, err = os.ReadFile(tmpFile.Name())
+		require.NoError(t, err)
+
+		fixture, err = os.ReadFile("testdata/bird/filter_one_prefix_compat")
 		require.NoError(t, err)
 
 		assert.Equal(t, string(fixture), string(data))
 	})
 
-	t.Run("one prefix, compat", func(t *testing.T) {
+	t.Run("filter up", func(t *testing.T) {
 		t.Parallel()
 
 		// open tempfile
 		tmpFile, err := os.CreateTemp(t.TempDir(), "bird_test")
 		require.NoError(t, err)
 		defer os.Remove(tmpFile.Name())
 
+		// no healthy prefixes, service explicitly healthy
 		prefixes := make(PrefixCollection)
+		prefixes["match_route"] = NewPrefixSet(&ServiceCheck{
+			FunctionName: "match_route",
+			state:        ServiceStateUp,
+		})
 
-		prefixes["other_function"] = NewPrefixSet("other_function")
-		for _, pref := range []string{"5.6.7.8/32", "6.7.8.9/26", "7.8.9.10/24"} {
-			_, prf, _ := net.ParseCIDR(pref)
-			prefixes["other_function"].Add(*prf)
-		}
+		// write bird config to it
+		err = writeBirdConfig(tmpFile.Name(), prefixes, false)
+		require.NoError(t, err)
 
+		// read data from temp file and compare it to file fixture
+		data, err := os.ReadFile(tmpFile.Name())
+		require.NoError(t, err)
+
+		fixture, err := os.ReadFile("testdata/bird/filter_up")
+		require.NoError(t, err)
+
+		assert.Equal(t, string(fixture), string(data))
+
+		// switch to compat mode and do it again
 		// write bird config to it
 		err = writeBirdConfig(tmpFile.Name(), prefixes, true)
 		require.NoError(t, err)
 
 		// read data from temp file and compare it to file fixture
-		data, err := os.ReadFile(tmpFile.Name())
+		data, err = os.ReadFile(tmpFile.Name())
 		require.NoError(t, err)
 
-		fixture, err := os.ReadFile("testdata/bird/config_compat")
+		fixture, err = os.ReadFile("testdata/bird/filter_up_compat")
 		require.NoError(t, err)
 
 		assert.Equal(t, string(fixture), string(data))

birdwatcher/config.go

@@ -139,10 +139,6 @@ func validateService(s *ServiceCheck) error {
 		s.Rise = defaultServiceRise
 	}
 
-	if len(s.Prefixes) == 0 {
-		return fmt.Errorf("service %s has no prefixes set", s.name)
-	}
-
 	return nil
 }
 

birdwatcher/config_test.go

@@ -52,16 +52,6 @@ func TestConfig(t *testing.T) {
 		}
 	})
 
-	// check for error for service with no prefixes
-	t.Run("service no prefixes", func(t *testing.T) {
-		t.Parallel()
-
-		err := ReadConfig(&Config{}, "testdata/config/service_noprefixes")
-		if assert.Error(t, err) {
-			assert.Regexp(t, regexp.MustCompile("^service .+ has no prefixes set"), err.Error())
-		}
-	})
-
 	// check for error for service with invalid prefix
 	t.Run("invalid prefix", func(t *testing.T) {
 		t.Parallel()
@@ -106,9 +96,7 @@ func TestConfig(t *testing.T) {
 		assert.Equal(t, defaultServiceRise, testConf.Services["foo"].Rise)
 		assert.Equal(t, defaultServiceTimeout, testConf.Services["foo"].Timeout)
 
-		if assert.Len(t, testConf.Services["foo"].prefixes, 1) {
-			assert.Equal(t, "192.168.0.0/24", testConf.Services["foo"].prefixes[0].String())
-		}
+		assert.Len(t, testConf.Services["foo"].prefixes, 0)
 
 		// check GetServices result
 		svcs := testConf.GetServices()

birdwatcher/healthcheck.go

@@ -87,10 +87,6 @@ func (h *HealthCheck) Start(services []*ServiceCheck, ready chan<- bool, status
 	}
 }
 
-func (h *HealthCheck) didReloadBefore() bool {
-	return h.reloadedBefore
-}
-
 func (h *HealthCheck) handleAction(action *Action, status chan string) {
 	for _, p := range action.Prefixes {
 		switch action.State {
@@ -160,7 +156,7 @@ func (h *HealthCheck) applyConfig(config Config, prefixes PrefixCollection) erro
 		// if config did not change, we should still reload if we don't know the
 		// state of BIRD
 		if errors.Is(err, errConfigIdentical) {
-			if h.didReloadBefore() {
+			if h.reloadedBefore {
 				cLog.Warning("config did not change, not reloading")
 
 				return nil
@@ -216,28 +212,31 @@ func (h *HealthCheck) applyConfig(config Config, prefixes PrefixCollection) erro
 }
 
 func (h *HealthCheck) addPrefix(svc *ServiceCheck, prefix net.IPNet) {
-	h.ensurePrefixSet(svc.FunctionName)
+	h.ensurePrefixSet(svc)
 
 	h.prefixes[svc.FunctionName].Add(prefix)
 	prefixStateMetric.WithLabelValues(svc.Name(), prefix.String()).Set(1.0)
 }
 
 func (h *HealthCheck) removePrefix(svc *ServiceCheck, prefix net.IPNet) {
-	h.ensurePrefixSet(svc.FunctionName)
+	h.ensurePrefixSet(svc)
 
 	h.prefixes[svc.FunctionName].Remove(prefix)
 	prefixStateMetric.WithLabelValues(svc.Name(), prefix.String()).Set(0.0)
 }
 
-func (h *HealthCheck) ensurePrefixSet(functionName string) {
+func (h *HealthCheck) ensurePrefixSet(svc *ServiceCheck) {
 	// make sure the top level map is prepared
 	if h.prefixes == nil {
 		h.prefixes = make(PrefixCollection)
 	}
 
-	// make sure a mapping for this function name exists
-	if _, found := h.prefixes[functionName]; !found {
-		h.prefixes[functionName] = NewPrefixSet(functionName)
+	// make sure a mapping for this function name exists and reflects the current
+	// health status of the service
+	if _, found := h.prefixes[svc.FunctionName]; found {
+		h.prefixes[svc.FunctionName].healthy = svc.IsUp()
+	} else {
+		h.prefixes[svc.FunctionName] = NewPrefixSet(svc)
 	}
 }
 

birdwatcher/healthcheck_test.go

@@ -62,24 +62,6 @@ func TestHealthCheck_removePrefix(t *testing.T) {
 	assert.Empty(t, testutil.ToFloat64(prefixStateMetric.WithLabelValues("svc1", "1.2.3.0/24")))
 }
 
-func TestHealthCheckDidReloadBefore(t *testing.T) {
-	t.Parallel()
-
-	hc := NewHealthCheck(Config{})
-
-	// expect both to fail
-	assert.False(t, hc.didReloadBefore())
-
-	// should succeed now
-	hc.reloadedBefore = true
-	assert.True(t, hc.didReloadBefore())
-
-	hc.reloadedBefore = false
-
-	// expect to fail again
-	assert.False(t, hc.didReloadBefore())
-}
-
 func TestHealthCheck_handleAction(t *testing.T) {
 	t.Parallel()
 

birdwatcher/prefixset.go

@@ -16,11 +16,15 @@ type PrefixCollection map[string]*PrefixSet
 type PrefixSet struct {
 	prefixes     []net.IPNet
 	functionName string
+	healthy      bool
 }
 
 // NewPrefixSet returns a new prefixset with given function name
-func NewPrefixSet(functionName string) *PrefixSet {
-	return &PrefixSet{functionName: functionName}
+func NewPrefixSet(svc *ServiceCheck) *PrefixSet {
+	return &PrefixSet{
+		functionName: svc.FunctionName,
+		healthy:      svc.IsUp(),
+	}
 }
 
 // FunctionName returns the function name
@@ -33,6 +37,10 @@ func (p PrefixSet) Prefixes() []net.IPNet {
 	return p.prefixes
 }
 
+func (p PrefixSet) Healthy() bool {
+	return p.healthy
+}
+
 // Add adds a prefix to the PrefixSet if it wasn't already in it
 func (p *PrefixSet) Add(prefix net.IPNet) {
 	pLog := log.WithFields(log.Fields{

birdwatcher/prefixset_test.go

@@ -10,7 +10,7 @@ import (
 func TestPrefixSet_Add(t *testing.T) {
 	t.Parallel()
 
-	p := NewPrefixSet("foobar")
+	p := NewPrefixSet(&ServiceCheck{FunctionName: "foobar"})
 	// should be empty
 	assert.Empty(t, p.prefixes)
 
@@ -44,7 +44,7 @@ func TestPrefixSet_Add(t *testing.T) {
 func TestPrefixSet_Remove(t *testing.T) {
 	t.Parallel()
 
-	p := NewPrefixSet("foobar")
+	p := NewPrefixSet(&ServiceCheck{FunctionName: "foobar"})
 
 	// add some prefixes
 	prefixes := make([]net.IPNet, 4)

birdwatcher/templates/functions.tpl

@@ -8,8 +8,12 @@ function {{.FunctionName}}(){{- if not $.CompatBird213 }} -> bool{{- end }}
 		{{.}}
 {{- end }}
 	];
+{{- else }}
+{{- if .Healthy }}
+	return true;
 {{- else }}
 	return false;
 {{- end }}
+{{- end }}
 }
 {{- end }}

birdwatcher/testdata/bird/filter_down_compat

@@ -0,0 +1,5 @@
+# DO NOT EDIT MANUALLY
+function match_route()
+{
+	return false;
+}

birdwatcher/testdata/bird/filter_one_prefix_compat

@@ -0,0 +1,10 @@
+# DO NOT EDIT MANUALLY
+function match_route()
+{
+	return net ~ [
+		1.2.3.4/32,
+		2.3.4.0/26,
+		3.4.5.0/24,
+		4.5.0.0/21
+	];
+}

birdwatcher/testdata/bird/filter_up

@@ -0,0 +1,5 @@
+# DO NOT EDIT MANUALLY
+function match_route() -> bool
+{
+	return true;
+}

birdwatcher/testdata/bird/filter_up_compat

@@ -0,0 +1,5 @@
+# DO NOT EDIT MANUALLY
+function match_route()
+{
+	return true;
+}

birdwatcher/testdata/config/minimal

@@ -1,4 +1,3 @@
 [services]
   [services."foo"]
     command = "/usr/bin/true"
-    prefixes = ["192.168.0.0/24"]