Small go style edits in stackdriver-nozzle

Author: Matthew Broomfield

src/stackdriver-nozzle/app/builder.go

@@ -180,7 +180,7 @@ func (a *App) buildEventFilters() (
 	monitoringWhitelist *nozzle.EventFilter,
 	err error,
 ) {
-	errs := []error{}
+	var errs []error
 	if len(a.c.EventFilterJSON.Blacklist) > 0 {
 		loggingBlacklist = &nozzle.EventFilter{}
 		monitoringBlacklist = &nozzle.EventFilter{}
@@ -205,7 +205,7 @@ func (a *App) buildEventFilters() (
 }
 
 func loadFilterRules(list []config.EventFilterRule, loggingFilter, monitoringFilter *nozzle.EventFilter) []error {
-	errs := []error{}
+	var errs []error
 	for _, rule := range list {
 		if !validSinks[rule.Sink] {
 			errs = append(errs, fmt.Errorf("rule %s has invalid sink %q", rule, rule.Sink))

src/stackdriver-nozzle/app/builder_test.go

@@ -47,22 +47,22 @@ var _ = Describe("Builder", func() {
 		},
 		Entry("translates nil lists", nil, nil, 0, 0, 0, 0),
 		Entry("translates logging blacklist",
-			[]config.EventFilterRule{{"name", "logging", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "logging", Regexp: ".*"}},
 			nil, 1, 0, 0, 0),
 		Entry("translates logging whitelist", nil,
-			[]config.EventFilterRule{{"name", "logging", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "logging", Regexp: ".*"}},
 			0, 1, 0, 0),
 		Entry("translates monitoring blacklist",
-			[]config.EventFilterRule{{"name", "monitoring", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "monitoring", Regexp: ".*"}},
 			nil, 0, 0, 1, 0),
 		Entry("translates monitoring whitelist", nil,
-			[]config.EventFilterRule{{"name", "monitoring", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "monitoring", Regexp: ".*"}},
 			0, 0, 0, 1),
 		Entry("translates all blacklist",
-			[]config.EventFilterRule{{"name", "all", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "all", Regexp: ".*"}},
 			nil, 1, 0, 1, 0),
 		Entry("translates all whitelist", nil,
-			[]config.EventFilterRule{{"name", "all", ".*"}},
+			[]config.EventFilterRule{{Type: "name", Sink: "all", Regexp: ".*"}},
 			0, 1, 0, 1),
 	)
 
@@ -78,11 +78,11 @@ var _ = Describe("Builder", func() {
 			Expect(mbl).To(BeNil())
 			Expect(mwl).To(BeNil())
 		},
-		Entry("errors on missing sinks", []config.EventFilterRule{{"name", "", ".*"}}),
-		Entry("errors on invalid sinks", []config.EventFilterRule{{"name", "foo", ".*"}}),
-		Entry("errors on missing types", []config.EventFilterRule{{"", "all", ".*"}}),
-		Entry("errors on invalid types", []config.EventFilterRule{{"foo", "all", ".*"}}),
-		Entry("errors on missing regexps", []config.EventFilterRule{{"name", "logging", ""}}),
-		Entry("errors on invalid regexps", []config.EventFilterRule{{"name", "logging", "$[}}})({"}}),
+		Entry("errors on missing sinks", []config.EventFilterRule{{Type: "name", Sink: "", Regexp: ".*"}}),
+		Entry("errors on invalid sinks", []config.EventFilterRule{{Type: "name", Sink: "foo", Regexp: ".*"}}),
+		Entry("errors on missing types", []config.EventFilterRule{{Type: "", Sink: "all", Regexp: ".*"}}),
+		Entry("errors on invalid types", []config.EventFilterRule{{Type: "foo", Sink: "all", Regexp: ".*"}}),
+		Entry("errors on missing regexps", []config.EventFilterRule{{Type: "name", Sink: "logging", Regexp: ""}}),
+		Entry("errors on invalid regexps", []config.EventFilterRule{{Type: "name", Sink: "logging", Regexp: "$[}}})({"}}),
 	)
 })

src/stackdriver-nozzle/app/runner.go

@@ -40,16 +40,17 @@ func Run(ctx context.Context, a *App) {
 
 	blockTillInterrupt()
 
-	a.logger.Info("app", lager.Data{"cleanup": "exit recieved, attempting to flush buffers"})
+	a.logger.Info("app", lager.Data{"cleanup": "exit received, attempting to flush buffers"})
 	if err := consumer.Stop(); err != nil {
 		a.logger.Error("nozzle.stop", err)
 	}
 	cancel()
 
 	t := time.NewTimer(5 * time.Second)
+	ticker := time.NewTicker(500 * time.Millisecond)
 	for {
 		select {
-		case <-time.Tick(500 * time.Millisecond):
+		case <-ticker.C:
 			if a.bufferEmpty() {
 				a.logger.Info("app", lager.Data{"cleanup": "The metrics buffer was successfully flushed before shutdown"})
 				return

src/stackdriver-nozzle/mocks/metric_adapter.go

@@ -34,10 +34,12 @@ func (m *MetricAdapter) PostMetrics(metrics []*messages.Metric) {
 	m.Lock()
 	defer m.Unlock()
 
-	m.PostMetricsCount += 1
+	m.PostMetricsCount++
 
 	if m.PostMetricsFn != nil {
-		m.PostMetricsFn(metrics)
+		if err := m.PostMetricsFn(metrics); err != nil {
+			panic(err)
+		}
 	}
 
 	m.PostedMetrics = append(m.PostedMetrics, metrics...)

src/stackdriver-nozzle/nozzle/counter_tracker.go

@@ -160,7 +160,7 @@ func (t *CounterTracker) expire() {
 	defer t.mu.Unlock()
 
 	for name, counter := range t.counters {
-		if time.Now().Sub(counter.lastSeenTime) > t.ttl {
+		if time.Since(counter.lastSeenTime) > t.ttl {
 			t.logger.Info("CounterTracker", lager.Data{
 				"info":    "removing expired counter",
 				"name":    name,

src/stackdriver-nozzle/nozzle/label_maker.go

@@ -186,11 +186,11 @@ func getTags(envelope *events.Envelope) string {
 	}
 	sort.Strings(tagKeys)
 
-	tagElems := make([]string, len(tags))
+	tagElements := make([]string, len(tags))
 	for i, k := range tagKeys {
-		tagElems[i] = k + "=" + tags[k]
+		tagElements[i] = k + "=" + tags[k]
 	}
-	return strings.Join(tagElems, ",")
+	return strings.Join(tagElements, ",")
 }
 
 func formatUUID(uuid *events.UUID) string {

src/stackdriver-nozzle/stackdriver/metric_adapter_test.go

@@ -205,7 +205,7 @@ var _ = Describe("MetricAdapter", func() {
 		callCount := 0
 		client.CreateMetricDescriptorFn = func(request *monitoringpb.CreateMetricDescriptorRequest) error {
 			mutex.Lock()
-			callCount += 1
+			callCount++
 			mutex.Unlock()
 
 			time.Sleep(100 * time.Millisecond)
@@ -229,8 +229,8 @@ var _ = Describe("MetricAdapter", func() {
 	It("returns the adapter even if we fail to list the metric descriptors", func() {
 		expectedErr := errors.New("fail")
 		client.ListErr = expectedErr
-		subject, err := NewMetricAdapter("my-awesome-project", client, 1, logger)
-		Expect(subject).To(Not(BeNil()))
+		subj, err := NewMetricAdapter("my-awesome-project", client, 1, logger)
+		Expect(subj).To(Not(BeNil()))
 		Expect(err).To(Equal(expectedErr))
 	})
 

src/stackdriver-nozzle/stackdriver/metric_client.go

@@ -103,7 +103,7 @@ func (m *metricClient) CreateMetricDescriptor(request *monitoringpb.CreateMetric
 func (m *metricClient) ListMetricDescriptors(request *monitoringpb.ListMetricDescriptorsRequest) ([]*metricpb.MetricDescriptor, error) {
 	it := m.sdMetricClient.ListMetricDescriptors(m.ctx, request)
 
-	descriptors := []*metricpb.MetricDescriptor{}
+	var descriptors []*metricpb.MetricDescriptor
 	for {
 		metricDescriptor, err := it.Next()
 		if err == iterator.Done {

src/stackdriver-nozzle/stackdriver/telemetry_sink_test.go

@@ -102,7 +102,7 @@ var _ = Describe("TelemetrySink", func() {
 	})
 
 	Context("with many metrics", func() {
-		values := []*expvar.KeyValue{}
+		var values []*expvar.KeyValue
 		BeforeEach(func() {
 			for i := 0; i < 300; i++ {
 				value := &telemetry.Counter{}

src/stackdriver-nozzle/telemetry/reporter.go

@@ -67,7 +67,7 @@ func (r *reporter) report() {
 }
 
 func (r *reporter) data() []*expvar.KeyValue {
-	points := []*expvar.KeyValue{}
+	var points []*expvar.KeyValue
 
 	forEachMetric(func(point expvar.KeyValue) {
 		points = append(points, &point)