Extract register view functionality (#1056)

* WIP

* Create separate Register*Views functions that are called from main.

api/agent/stats.go

@@ -2,6 +2,7 @@ package agent
 
 import (
 	"context"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/stats"
@@ -68,49 +69,134 @@ const (
 )
 
 var (
-	queuedMeasure     *stats.Int64Measure
-	callsMeasure      *stats.Int64Measure // TODO this is a dupe of sum {complete,failed} ?
-	runningMeasure    *stats.Int64Measure
-	completedMeasure  *stats.Int64Measure
-	failedMeasure     *stats.Int64Measure
-	timedoutMeasure   *stats.Int64Measure
-	errorsMeasure     *stats.Int64Measure
-	serverBusyMeasure *stats.Int64Measure
+	queuedMeasure = makeMeasure(queuedMetricName, "calls currently queued against agent", "")
+	// TODO this is a dupe of sum {complete,failed} ?
+	callsMeasure           = makeMeasure(callsMetricName, "calls created in agent", "")
+	runningMeasure         = makeMeasure(runningMetricName, "calls currently running in agent", "")
+	completedMeasure       = makeMeasure(completedMetricName, "calls completed in agent", "")
+	failedMeasure          = makeMeasure(failedMetricName, "calls failed in agent", "")
+	timedoutMeasure        = makeMeasure(timedoutMetricName, "calls timed out in agent", "")
+	errorsMeasure          = makeMeasure(errorsMetricName, "calls errored in agent", "")
+	serverBusyMeasure      = makeMeasure(serverBusyMetricName, "calls where server was too busy in agent", "")
+	dockerMeasures         = initDockerMeasures()
+	containerGaugeMeasures = initContainerGaugeMeasures()
+	containerTimeMeasures  = initContainerTimeMeasures()
 )
 
-func init() {
-	queuedMeasure = makeMeasure(queuedMetricName, "calls currently queued against agent", "", view.Sum())
-	callsMeasure = makeMeasure(callsMetricName, "calls created in agent", "", view.Sum())
-	runningMeasure = makeMeasure(runningMetricName, "calls currently running in agent", "", view.Sum())
-	completedMeasure = makeMeasure(completedMetricName, "calls completed in agent", "", view.Sum())
-	failedMeasure = makeMeasure(failedMetricName, "calls failed in agent", "", view.Sum())
-	timedoutMeasure = makeMeasure(timedoutMetricName, "calls timed out in agent", "", view.Sum())
-	errorsMeasure = makeMeasure(errorsMetricName, "calls errored in agent", "", view.Sum())
-	serverBusyMeasure = makeMeasure(serverBusyMetricName, "calls where server was too busy in agent", "", view.Sum())
-}
-
-func makeMeasure(name string, desc string, unit string, agg *view.Aggregation) *stats.Int64Measure {
-	appKey, err := tag.NewKey("fn_appname")
-	if err != nil {
-		logrus.Fatal(err)
-	}
-	pathKey, err := tag.NewKey("fn_path")
-	if err != nil {
-		logrus.Fatal(err)
-	}
-
-	measure := stats.Int64(name, desc, unit)
-	err = view.Register(
-		&view.View{
-			Name:        name,
-			Description: desc,
-			TagKeys:     []tag.Key{appKey, pathKey},
-			Measure:     measure,
-			Aggregation: agg,
-		},
+// RegisterAgentViews creates and registers all agent views
+func RegisterAgentViews(tagKeys []string) {
+	err := view.Register(
+		createView(queuedMeasure, view.Sum(), tagKeys),
+		createView(callsMeasure, view.Sum(), tagKeys),
+		createView(runningMeasure, view.Sum(), tagKeys),
+		createView(completedMeasure, view.Sum(), tagKeys),
+		createView(failedMeasure, view.Sum(), tagKeys),
+		createView(timedoutMeasure, view.Sum(), tagKeys),
+		createView(errorsMeasure, view.Sum(), tagKeys),
+		createView(serverBusyMeasure, view.Sum(), tagKeys),
 	)
 	if err != nil {
-		logrus.WithError(err).Fatal("cannot create view")
+		logrus.WithError(err).Fatal("cannot register view")
 	}
-	return measure
+}
+
+// RegisterDockerViews creates a and registers Docker views with provided tag keys
+func RegisterDockerViews(tagKeys []string) {
+	for _, m := range dockerMeasures {
+		v := createView(m, view.Distribution(), tagKeys)
+		if err := view.Register(v); err != nil {
+			logrus.WithError(err).Fatal("cannot register view")
+		}
+	}
+}
+
+// RegisterContainerViews creates and register containers views with provided tag keys
+func RegisterContainerViews(tagKeys []string) {
+	// Create views for container measures
+	for i, key := range containerGaugeKeys {
+		if key == "" {
+			continue
+		}
+		v := createView(containerGaugeMeasures[i], view.Count(), tagKeys)
+		if err := view.Register(v); err != nil {
+			logrus.WithError(err).Fatal("cannot register view")
+		}
+	}
+
+	for i, key := range containerTimeKeys {
+		if key == "" {
+			continue
+		}
+		v := createView(containerTimeMeasures[i], view.Distribution(), tagKeys)
+		if err := view.Register(v); err != nil {
+			logrus.WithError(err).Fatal("cannot register view")
+		}
+	}
+}
+
+// initDockerMeasures initializes Docker related measures
+func initDockerMeasures() map[string]*stats.Int64Measure {
+	// TODO this is nasty figure out how to use opencensus to not have to declare these
+	keys := []string{"net_rx", "net_tx", "mem_limit", "mem_usage", "disk_read", "disk_write", "cpu_user", "cpu_total", "cpu_kernel"}
+	measures := make(map[string]*stats.Int64Measure, len(keys))
+	for _, key := range keys {
+		units := "bytes"
+		if strings.Contains(key, "cpu") {
+			units = "cpu"
+		}
+		measures[key] = makeMeasure("docker_stats_"+key, "docker container stats for "+key, units)
+	}
+	return measures
+}
+
+func initContainerGaugeMeasures() []*stats.Int64Measure {
+	gaugeMeasures := make([]*stats.Int64Measure, len(containerGaugeKeys))
+	for i, key := range containerGaugeKeys {
+		if key == "" { // leave nil intentionally, let it panic
+			continue
+		}
+		gaugeMeasures[i] = makeMeasure(key, "containers in state "+key, "")
+	}
+	return gaugeMeasures
+}
+
+func initContainerTimeMeasures() []*stats.Int64Measure {
+	// TODO(reed): do we have to do this? the measurements will be tagged on the context, will they be propagated
+	// or we have to white list them in the view for them to show up? test...
+
+	timeMeasures := make([]*stats.Int64Measure, len(containerTimeKeys))
+	for i, key := range containerTimeKeys {
+		if key == "" {
+			continue
+		}
+		timeMeasures[i] = makeMeasure(key, "time spent in container state "+key, "ms")
+	}
+
+	return timeMeasures
+}
+
+func createView(measure stats.Measure, agg *view.Aggregation, tagKeys []string) *view.View {
+	return &view.View{
+		Name:        measure.Name(),
+		Description: measure.Description(),
+		Measure:     measure,
+		TagKeys:     makeKeys(tagKeys),
+		Aggregation: agg,
+	}
+}
+
+func makeMeasure(name string, desc string, unit string) *stats.Int64Measure {
+	return stats.Int64(name, desc, unit)
+}
+
+func makeKeys(names []string) []tag.Key {
+	tagKeys := make([]tag.Key, len(names))
+	for i, name := range names {
+		key, err := tag.NewKey(name)
+		if err != nil {
+			logrus.Fatal(err)
+		}
+		tagKeys[i] = key
+	}
+	return tagKeys
 }