feat: add stat for domain not found (#624)

Signed-off-by: Josh Jaques <[email protected]>

src/config/config_impl.go

@@ -285,6 +285,8 @@ func (this *rateLimitConfigImpl) GetLimit(
 	value := this.domains[domain]
 	if value == nil {
 		logger.Debugf("unknown domain '%s'", domain)
+		domainStats := this.statsManager.NewDomainStats(domain)
+		domainStats.NotFound.Inc()
 		return rateLimit
 	}
 

src/stats/manager.go

@@ -9,6 +9,9 @@ type Manager interface {
 	// NewStats provides a RateLimitStats structure associated with a given descriptorKey.
 	// Multiple calls with the same descriptorKey argument are guaranteed to be equivalent.
 	NewStats(descriptorKey string) RateLimitStats
+	// Gets stats for a domain (when no descriptors are found)
+	// Multiple calls with the same domain argument are guaranteed to be equivalent.
+	NewDomainStats(domain string) DomainStats
 	// Initializes a ShouldRateLimitStats structure.
 	// Multiple calls to this method are idempotent.
 	NewShouldRateLimitStats() ShouldRateLimitStats
@@ -52,3 +55,9 @@ type RateLimitStats struct {
 	WithinLimit             gostats.Counter
 	ShadowMode              gostats.Counter
 }
+
+// Stats for a domain entry
+type DomainStats struct {
+	Key      string
+	NotFound gostats.Counter
+}

src/stats/manager_impl.go

@@ -39,6 +39,13 @@ func (this *ManagerImpl) NewStats(key string) RateLimitStats {
 	return ret
 }
 
+func (this *ManagerImpl) NewDomainStats(domain string) DomainStats {
+	ret := DomainStats{}
+	domain = utils.SanitizeStatName(domain)
+	ret.NotFound = this.rlStatsScope.NewCounter(domain + ".domain_not_found")
+	return ret
+}
+
 func (this *ManagerImpl) NewShouldRateLimitStats() ShouldRateLimitStats {
 	ret := ShouldRateLimitStats{}
 	ret.RedisError = this.shouldRateLimitScope.NewCounter("redis_error")

test/config/config_test.go

@@ -33,8 +33,11 @@ func TestBasicConfig(t *testing.T) {
 	rlConfig := config.NewRateLimitConfigImpl(loadFile("basic_config.yaml"), mockstats.NewMockStatManager(stats), false)
 	rlConfig.Dump()
 	assert.Equal(rlConfig.IsEmptyDomains(), false)
+	assert.EqualValues(0, stats.NewCounter("foo_domain.domain_not_found").Value())
 	assert.Nil(rlConfig.GetLimit(context.TODO(), "foo_domain", &pb_struct.RateLimitDescriptor{}))
+	assert.EqualValues(1, stats.NewCounter("foo_domain.domain_not_found").Value())
 	assert.Nil(rlConfig.GetLimit(context.TODO(), "test-domain", &pb_struct.RateLimitDescriptor{}))
+	assert.EqualValues(0, stats.NewCounter("test-domain.domain_not_found").Value())
 
 	rl := rlConfig.GetLimit(
 		context.TODO(), "test-domain",

test/mocks/stats/manager.go

@@ -48,6 +48,15 @@ func (m *MockStatManager) NewStats(key string) stats.RateLimitStats {
 	return ret
 }
 
+func (m *MockStatManager) NewDomainStats(key string) stats.DomainStats {
+	ret := stats.DomainStats{}
+	logger.Debugf("outputing test domain stats %s", key)
+	ret.Key = key
+	ret.NotFound = m.store.NewCounter(key + ".domain_not_found")
+
+	return ret
+}
+
 func NewMockStatManager(store gostats.Store) stats.Manager {
 	return &MockStatManager{store: store}
 }