WIP metrics registry

This commit specifically doesn't fix most tests as this takes a lot of
time and also doesn't do a lot of other stuff:
1. breaking metrics in other ways as that might be useful to be
   kept for a little bit at least
2. also doesn't try to do anything that isn't absolutely necessary to
   make the registry work
3. doesnt move the metrics stuff around, although I would expect the
   Registry and the Metric type will end up in a `metrics` package later
   on ...

cmd/run.go

@@ -49,7 +49,10 @@ import (
 	"go.k6.io/k6/js"
 	"go.k6.io/k6/lib"
 	"go.k6.io/k6/lib/consts"
+	"go.k6.io/k6/lib/metrics"
 	"go.k6.io/k6/loader"
+	"go.k6.io/k6/output"
+	"go.k6.io/k6/stats"
 	"go.k6.io/k6/ui/pb"
 )
 
@@ -153,10 +156,6 @@ a commandline interface for interacting with it.`,
 			//    can start winding down its metrics processing.
 			globalCtx, globalCancel := context.WithCancel(ctx)
 			defer globalCancel()
-			lingerCtx, lingerCancel := context.WithCancel(globalCtx)
-			defer lingerCancel()
-			runCtx, runCancel := context.WithCancel(lingerCtx)
-			defer runCancel()
 
 			// Create a local execution scheduler wrapping the runner.
 			logger.Debug("Initializing the execution scheduler...")
@@ -197,6 +196,16 @@ a commandline interface for interacting with it.`,
 				return err
 			}
 
+			registry := stats.NewRegistry(engine.Samples)
+			builtInMetrics := metrics.RegisterBuiltinMetrics(registry)
+			globalCtx = stats.WithRegistry(globalCtx, registry)
+			globalCtx = metrics.WithBuiltinMetrics(globalCtx, builtInMetrics)
+
+			lingerCtx, lingerCancel := context.WithCancel(globalCtx)
+			defer lingerCancel()
+			runCtx, runCancel := context.WithCancel(lingerCtx)
+			defer runCancel()
+
 			// Spin up the REST API server, if not disabled.
 			if address != "" {
 				initBar.Modify(pb.WithConstProgress(0, "Init API server"))
@@ -216,11 +225,11 @@ a commandline interface for interacting with it.`,
 
 			// We do this here so we can get any output URLs below.
 			initBar.Modify(pb.WithConstProgress(0, "Starting outputs"))
-			err = engine.StartOutputs()
+			err = StartOutputs(logger, outputs, engine, builtInMetrics)
 			if err != nil {
 				return err
 			}
-			defer engine.StopOutputs()
+			defer StopOutputs(logger, outputs)
 
 			printExecutionDescription(
 				"local", filename, "", conf, execScheduler.GetState().ExecutionTuple,
@@ -442,3 +451,53 @@ func handleSummaryResult(fs afero.Fs, stdOut, stdErr io.Writer, result map[strin
 
 	return consolidateErrorMessage(errs, "Could not save some summary information:")
 }
+
+// StartOutputs spins up all configured outputs, giving the thresholds to any
+// that can accept them. And if some output fails, stop the already started
+// ones. This may take some time, since some outputs make initial network
+// requests to set up whatever remote services are going to listen to them.
+func StartOutputs(
+	logger logrus.FieldLogger,
+	outputs []output.Output,
+	engine *core.Engine,
+	builtinMetrics *metrics.BuiltInMetrics,
+) error {
+	logger.Debugf("Starting %d outputs...", len(outputs))
+	for i, out := range outputs {
+		if thresholdOut, ok := out.(output.WithThresholds); ok {
+			thresholdOut.SetThresholds(engine.Options.Thresholds)
+		}
+
+		if stopOut, ok := out.(output.WithTestRunStop); ok {
+			stopOut.SetTestRunStopCallback(
+				func(err error) {
+					logger.WithError(err).Error("Received error to stop from output")
+					engine.Stop()
+				})
+		}
+
+		if builtinMetricOut, ok := out.(output.WithBuiltinMetrics); ok {
+			builtinMetricOut.SetBuiltinMetrics(builtinMetrics)
+		}
+
+		if err := out.Start(); err != nil {
+			stopOutputs(logger, outputs, i)
+			return err
+		}
+	}
+	return nil
+}
+
+// StopOutputs stops all configured outputs.
+func StopOutputs(logger logrus.FieldLogger, outputs []output.Output) {
+	stopOutputs(logger, outputs, len(outputs))
+}
+
+func stopOutputs(logger logrus.FieldLogger, outputs []output.Output, upToID int) {
+	logger.Debugf("Stopping %d outputs...", upToID)
+	for i := 0; i < upToID; i++ {
+		if err := outputs[i].Stop(); err != nil {
+			logger.WithError(err).Errorf("Stopping output %d failed", i)
+		}
+	}
+}

core/engine.go

@@ -67,7 +67,8 @@ type Engine struct {
 	Metrics     map[string]*stats.Metric
 	MetricsLock sync.Mutex
 
-	Samples chan stats.SampleContainer
+	builtInMetrics *metrics.BuiltInMetrics
+	Samples        chan stats.SampleContainer
 
 	// Assigned to metrics upon first received sample.
 	thresholds map[string]stats.Thresholds
@@ -147,6 +148,10 @@ func (e *Engine) StartOutputs() error {
 				})
 		}
 
+		if builtinMetricOut, ok := out.(output.WithBuiltinMetrics); ok {
+			builtinMetricOut.SetBuiltinMetrics(e.builtInMetrics)
+		}
+
 		if err := out.Start(); err != nil {
 			e.stopOutputs(i)
 			return err
@@ -184,6 +189,7 @@ func (e *Engine) stopOutputs(upToID int) {
 //    returned by cancelling the globalCtx
 //  - The second returned lambda can be used to wait for that process to finish.
 func (e *Engine) Init(globalCtx, runCtx context.Context) (run func() error, wait func(), err error) {
+	e.builtInMetrics = metrics.GetBuiltInMetrics(globalCtx)
 	e.logger.Debug("Initialization starting...")
 	// TODO: if we ever need metrics processing in the init context, we can move
 	// this below the other components... or even start them concurrently?
@@ -416,12 +422,12 @@ func (e *Engine) emitMetrics() {
 		Samples: []stats.Sample{
 			{
 				Time:   t,
-				Metric: metrics.VUs,
+				Metric: e.builtInMetrics.VUs,
 				Value:  float64(executionState.GetCurrentlyActiveVUsCount()),
 				Tags:   e.Options.RunTags,
 			}, {
 				Time:   t,
-				Metric: metrics.VUsMax,
+				Metric: e.builtInMetrics.VUsMax,
 				Value:  float64(executionState.GetInitializedVUsCount()),
 				Tags:   e.Options.RunTags,
 			},

js/modules/k6/grpc/client.go

@@ -493,7 +493,7 @@ func (c *Client) HandleRPC(ctx context.Context, stat grpcstats.RPCStats) {
 		stats.PushIfNotDone(ctx, state.Samples, stats.ConnectedSamples{
 			Samples: []stats.Sample{
 				{
-					Metric: metrics.GRPCReqDuration,
+					Metric: metrics.GetBuiltInMetrics(ctx).GRPCReqDuration,
 					Tags:   sampleTags,
 					Value:  stats.D(s.EndTime.Sub(s.BeginTime)),
 					Time:   s.EndTime,

js/modules/k6/k6.go

@@ -101,9 +101,10 @@ func (*K6) Group(ctx context.Context, name string, fn goja.Callable) (goja.Value
 	t := time.Now()
 
 	tags := state.CloneTags()
+
 	stats.PushIfNotDone(ctx, state.Samples, stats.Sample{
 		Time:   t,
-		Metric: metrics.GroupDuration,
+		Metric: metrics.GetBuiltInMetrics(ctx).GroupDuration,
 		Tags:   stats.IntoSampleTags(&tags),
 		Value:  stats.D(t.Sub(startTime)),
 	})
@@ -165,12 +166,13 @@ func (*K6) Check(ctx context.Context, arg0, checks goja.Value, extras ...goja.Va
 		select {
 		case <-ctx.Done():
 		default:
+			builtin := metrics.GetBuiltInMetrics(ctx)
 			if val.ToBoolean() {
 				atomic.AddInt64(&check.Passes, 1)
-				stats.PushIfNotDone(ctx, state.Samples, stats.Sample{Time: t, Metric: metrics.Checks, Tags: sampleTags, Value: 1})
+				stats.PushIfNotDone(ctx, state.Samples, stats.Sample{Time: t, Metric: builtin.Checks, Tags: sampleTags, Value: 1})
 			} else {
 				atomic.AddInt64(&check.Fails, 1)
-				stats.PushIfNotDone(ctx, state.Samples, stats.Sample{Time: t, Metric: metrics.Checks, Tags: sampleTags, Value: 0})
+				stats.PushIfNotDone(ctx, state.Samples, stats.Sample{Time: t, Metric: builtin.Checks, Tags: sampleTags, Value: 0})
 				// A single failure makes the return value false.
 				succ = false
 			}