Adding unit tests to opentelemetry tracing

Refractor newExporter and newTracer, add unit tests to them
This PR is part of issue 7493

Signed-off-by: Tony Fang <nenghui.fang@gmail.com>

tracing/plugin/otlp.go

@@ -23,6 +23,7 @@ import (
 	"net/url"
 	"time"
 
+	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/plugin"
 	"github.com/containerd/containerd/tracing"
@@ -63,7 +64,26 @@ func init() {
 		Requires: []plugin.Type{plugin.TracingProcessorPlugin},
 		Config:   &TraceConfig{ServiceName: "containerd", TraceSamplingRatio: 1.0},
 		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
-			return newTracer(ic)
+			//get TracingProcessorPlugin which is a dependency
+			plugins, err := ic.GetByType(plugin.TracingProcessorPlugin)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get tracing processors: %w", err)
+			}
+			procs := make([]sdktrace.SpanProcessor, 0, len(plugins))
+			for id, pctx := range plugins {
+				p, err := pctx.Instance()
+				if err != nil {
+					if plugin.IsSkipPlugin(err) {
+						log.G(ic.Context).WithError(err).Infof("skipping tracing processor initialization (no tracing plugin)")
+					} else {
+						log.G(ic.Context).WithError(err).Errorf("failed to initialize a tracing processor %q", id)
+					}
+					continue
+				}
+				proc := p.(sdktrace.SpanProcessor)
+				procs = append(procs, proc)
+			}
+			return newTracer(ic.Context, ic.Config.(*TraceConfig), procs)
 		},
 	})
 
@@ -105,7 +125,7 @@ func newExporter(ctx context.Context, cfg *OTLPConfig) (*otlptrace.Exporter, err
 	if cfg.Protocol == "http/protobuf" || cfg.Protocol == "" {
 		u, err := url.Parse(cfg.Endpoint)
 		if err != nil {
-			return nil, fmt.Errorf("OpenTelemetry endpoint %q is invalid: %w", cfg.Endpoint, err)
+			return nil, fmt.Errorf("OpenTelemetry endpoint %q %w : %v", cfg.Endpoint, errdefs.ErrInvalidArgument, err)
 		}
 		opts := []otlptracehttp.Option{
 			otlptracehttp.WithEndpoint(u.Host),
@@ -124,7 +144,7 @@ func newExporter(ctx context.Context, cfg *OTLPConfig) (*otlptrace.Exporter, err
 		return otlptracegrpc.New(ctx, opts...)
 	} else {
 		// Other protocols such as "http/json" are not supported.
-		return nil, fmt.Errorf("OpenTelemetry protocol %q is not supported", cfg.Protocol)
+		return nil, fmt.Errorf("OpenTelemetry protocol %q : %w", cfg.Protocol, errdefs.ErrNotImplemented)
 	}
 }
 
@@ -132,9 +152,7 @@ func newExporter(ctx context.Context, cfg *OTLPConfig) (*otlptrace.Exporter, err
 // its sampling ratio and returns io.Closer.
 //
 // Note that this function sets process-wide tracing configuration.
-func newTracer(ic *plugin.InitContext) (io.Closer, error) {
+func newTracer(ctx context.Context, config *TraceConfig, procs []sdktrace.SpanProcessor) (io.Closer, error) {
-	ctx := ic.Context
-	config := ic.Config.(*TraceConfig)
 
 	res, err := resource.New(ctx,
 		resource.WithHost(),
@@ -154,25 +172,8 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 		sdktrace.WithResource(res),
 	}
 
-	ls, err := ic.GetByType(plugin.TracingProcessorPlugin)
+	for _, proc := range procs {
-	if err != nil {
-		return nil, fmt.Errorf("failed to get tracing processors: %w", err)
-	}
-
-	procs := make([]sdktrace.SpanProcessor, 0, len(ls))
-	for id, pctx := range ls {
-		p, err := pctx.Instance()
-		if err != nil {
-			if plugin.IsSkipPlugin(err) {
-				log.G(ctx).WithError(err).Infof("skipping tracing processor initialization (no tracing plugin)")
-			} else {
-				log.G(ctx).WithError(err).Errorf("failed to initialize a tracing processor %q", id)
-			}
-			continue
-		}
-		proc := p.(sdktrace.SpanProcessor)
 		opts = append(opts, sdktrace.WithSpanProcessor(proc))
-		procs = append(procs, proc)
 	}
 
 	provider := sdktrace.NewTracerProvider(opts...)
@@ -189,6 +190,7 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 		}
 		return nil
 	}}, nil
+
 }
 
 // Returns a composite TestMap propagator

tracing/plugin/otlp_test.go

@@ -0,0 +1,118 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package plugin
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/containerd/containerd/errdefs"
+	"go.opentelemetry.io/otel/sdk/trace"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/sdk/trace/tracetest"
+)
+
+// TestNewExporter runs tests with different combinations of configuration for NewExporter function
+func TestNewExporter(t *testing.T) {
+
+	for _, testcase := range []struct {
+		name   string
+		input  OTLPConfig
+		output error
+	}{
+		{
+			name: "Test http/protobuf protocol, expect no error",
+			input: OTLPConfig{Endpoint: "http://localhost:4318",
+				Protocol: "http/protobuf",
+				Insecure: false},
+			output: nil,
+		},
+		{
+			name: "Test invalid endpoint, expect ErrInvalidArgument error",
+			input: OTLPConfig{Endpoint: "http://localhost\n:4318",
+				Protocol: "http/protobuf",
+				Insecure: false},
+			output: errdefs.ErrInvalidArgument,
+		},
+		{
+			name: "Test default protocol, expect no error",
+			input: OTLPConfig{Endpoint: "http://localhost:4318",
+				Protocol: "",
+				Insecure: false},
+			output: nil,
+		},
+		{
+			name: "Test grpc protocol, expect no error",
+			input: OTLPConfig{Endpoint: "http://localhost:4317",
+				Protocol: "grpc",
+				Insecure: false},
+			output: nil,
+		},
+		{
+			name: "Test http/json protocol which is not supported, expect not implemented error",
+			input: OTLPConfig{Endpoint: "http://localhost:4318",
+				Protocol: "http/json",
+				Insecure: false},
+			output: errdefs.ErrNotImplemented,
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			t.Logf("input: %v", testcase.input)
+
+			ctx := context.TODO()
+			exp, err := newExporter(ctx, &testcase.input)
+			t.Logf("output: %v", err)
+
+			if err == nil {
+				if err != testcase.output {
+					t.Fatalf("Expect to get error: %v, however no error got\n", testcase.output)
+				} else if exp == nil {
+					t.Fatalf("Something went wrong, Exporter not created as expected\n")
+				}
+			} else {
+				if !errors.Is(err, testcase.output) {
+					t.Fatalf("Expect to get error: %v, however error %v returned\n", testcase.output, err)
+				}
+			}
+
+		})
+	}
+}
+
+// TestNewTracer runs test for NewTracer function
+func TestNewTracer(t *testing.T) {
+
+	config := &TraceConfig{ServiceName: "containerd", TraceSamplingRatio: 1.0}
+	t.Logf("config: %v", config)
+
+	procs := make([]sdktrace.SpanProcessor, 0, 1)
+
+	//Create a dummy in memory exporter for test
+	exp := tracetest.NewInMemoryExporter()
+	proc := trace.NewBatchSpanProcessor(exp)
+
+	procs = append(procs, proc)
+
+	ctx := context.TODO()
+	tracerCloser, err := newTracer(ctx, config, procs)
+	if err != nil {
+		t.Fatalf("Something went wrong, Tracer not created as expected\n")
+	}
+
+	defer tracerCloser.Close()
+}

vendor/go.opentelemetry.io/otel/sdk/trace/tracetest/exporter.go

@@ -0,0 +1,85 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package tracetest is a testing helper package for the SDK. User can
+// configure no-op or in-memory exporters to verify different SDK behaviors or
+// custom instrumentation.
+package tracetest // import "go.opentelemetry.io/otel/sdk/trace/tracetest"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/sdk/trace"
+)
+
+var _ trace.SpanExporter = (*NoopExporter)(nil)
+
+// NewNoopExporter returns a new no-op exporter.
+func NewNoopExporter() *NoopExporter {
+	return new(NoopExporter)
+}
+
+// NoopExporter is an exporter that drops all received spans and performs no
+// action.
+type NoopExporter struct{}
+
+// ExportSpans handles export of spans by dropping them.
+func (nsb *NoopExporter) ExportSpans(context.Context, []trace.ReadOnlySpan) error { return nil }
+
+// Shutdown stops the exporter by doing nothing.
+func (nsb *NoopExporter) Shutdown(context.Context) error { return nil }
+
+var _ trace.SpanExporter = (*InMemoryExporter)(nil)
+
+// NewInMemoryExporter returns a new InMemoryExporter.
+func NewInMemoryExporter() *InMemoryExporter {
+	return new(InMemoryExporter)
+}
+
+// InMemoryExporter is an exporter that stores all received spans in-memory.
+type InMemoryExporter struct {
+	mu sync.Mutex
+	ss SpanStubs
+}
+
+// ExportSpans handles export of spans by storing them in memory.
+func (imsb *InMemoryExporter) ExportSpans(_ context.Context, spans []trace.ReadOnlySpan) error {
+	imsb.mu.Lock()
+	defer imsb.mu.Unlock()
+	imsb.ss = append(imsb.ss, SpanStubsFromReadOnlySpans(spans)...)
+	return nil
+}
+
+// Shutdown stops the exporter by clearing spans held in memory.
+func (imsb *InMemoryExporter) Shutdown(context.Context) error {
+	imsb.Reset()
+	return nil
+}
+
+// Reset the current in-memory storage.
+func (imsb *InMemoryExporter) Reset() {
+	imsb.mu.Lock()
+	defer imsb.mu.Unlock()
+	imsb.ss = nil
+}
+
+// GetSpans returns the current in-memory stored spans.
+func (imsb *InMemoryExporter) GetSpans() SpanStubs {
+	imsb.mu.Lock()
+	defer imsb.mu.Unlock()
+	ret := make(SpanStubs, len(imsb.ss))
+	copy(ret, imsb.ss)
+	return ret
+}

vendor/go.opentelemetry.io/otel/sdk/trace/tracetest/recorder.go

@@ -0,0 +1,92 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tracetest // import "go.opentelemetry.io/otel/sdk/trace/tracetest"
+
+import (
+	"context"
+	"sync"
+
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+)
+
+// SpanRecorder records started and ended spans.
+type SpanRecorder struct {
+	startedMu sync.RWMutex
+	started   []sdktrace.ReadWriteSpan
+
+	endedMu sync.RWMutex
+	ended   []sdktrace.ReadOnlySpan
+}
+
+var _ sdktrace.SpanProcessor = (*SpanRecorder)(nil)
+
+// NewSpanRecorder returns a new initialized SpanRecorder.
+func NewSpanRecorder() *SpanRecorder {
+	return new(SpanRecorder)
+}
+
+// OnStart records started spans.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) OnStart(_ context.Context, s sdktrace.ReadWriteSpan) {
+	sr.startedMu.Lock()
+	defer sr.startedMu.Unlock()
+	sr.started = append(sr.started, s)
+}
+
+// OnEnd records completed spans.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) OnEnd(s sdktrace.ReadOnlySpan) {
+	sr.endedMu.Lock()
+	defer sr.endedMu.Unlock()
+	sr.ended = append(sr.ended, s)
+}
+
+// Shutdown does nothing.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) Shutdown(context.Context) error {
+	return nil
+}
+
+// ForceFlush does nothing.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) ForceFlush(context.Context) error {
+	return nil
+}
+
+// Started returns a copy of all started spans that have been recorded.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) Started() []sdktrace.ReadWriteSpan {
+	sr.startedMu.RLock()
+	defer sr.startedMu.RUnlock()
+	dst := make([]sdktrace.ReadWriteSpan, len(sr.started))
+	copy(dst, sr.started)
+	return dst
+}
+
+// Ended returns a copy of all ended spans that have been recorded.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) Ended() []sdktrace.ReadOnlySpan {
+	sr.endedMu.RLock()
+	defer sr.endedMu.RUnlock()
+	dst := make([]sdktrace.ReadOnlySpan, len(sr.ended))
+	copy(dst, sr.ended)
+	return dst
+}

vendor/go.opentelemetry.io/otel/sdk/trace/tracetest/span.go

@@ -0,0 +1,167 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tracetest // import "go.opentelemetry.io/otel/sdk/trace/tracetest"
+
+import (
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	tracesdk "go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// SpanStubs is a slice of SpanStub use for testing an SDK.
+type SpanStubs []SpanStub
+
+// SpanStubsFromReadOnlySpans returns SpanStubs populated from ro.
+func SpanStubsFromReadOnlySpans(ro []tracesdk.ReadOnlySpan) SpanStubs {
+	if len(ro) == 0 {
+		return nil
+	}
+
+	s := make(SpanStubs, 0, len(ro))
+	for _, r := range ro {
+		s = append(s, SpanStubFromReadOnlySpan(r))
+	}
+
+	return s
+}
+
+// Snapshots returns s as a slice of ReadOnlySpans.
+func (s SpanStubs) Snapshots() []tracesdk.ReadOnlySpan {
+	if len(s) == 0 {
+		return nil
+	}
+
+	ro := make([]tracesdk.ReadOnlySpan, len(s))
+	for i := 0; i < len(s); i++ {
+		ro[i] = s[i].Snapshot()
+	}
+	return ro
+}
+
+// SpanStub is a stand-in for a Span.
+type SpanStub struct {
+	Name                   string
+	SpanContext            trace.SpanContext
+	Parent                 trace.SpanContext
+	SpanKind               trace.SpanKind
+	StartTime              time.Time
+	EndTime                time.Time
+	Attributes             []attribute.KeyValue
+	Events                 []tracesdk.Event
+	Links                  []tracesdk.Link
+	Status                 tracesdk.Status
+	DroppedAttributes      int
+	DroppedEvents          int
+	DroppedLinks           int
+	ChildSpanCount         int
+	Resource               *resource.Resource
+	InstrumentationLibrary instrumentation.Library
+}
+
+// SpanStubFromReadOnlySpan returns a SpanStub populated from ro.
+func SpanStubFromReadOnlySpan(ro tracesdk.ReadOnlySpan) SpanStub {
+	if ro == nil {
+		return SpanStub{}
+	}
+
+	return SpanStub{
+		Name:                   ro.Name(),
+		SpanContext:            ro.SpanContext(),
+		Parent:                 ro.Parent(),
+		SpanKind:               ro.SpanKind(),
+		StartTime:              ro.StartTime(),
+		EndTime:                ro.EndTime(),
+		Attributes:             ro.Attributes(),
+		Events:                 ro.Events(),
+		Links:                  ro.Links(),
+		Status:                 ro.Status(),
+		DroppedAttributes:      ro.DroppedAttributes(),
+		DroppedEvents:          ro.DroppedEvents(),
+		DroppedLinks:           ro.DroppedLinks(),
+		ChildSpanCount:         ro.ChildSpanCount(),
+		Resource:               ro.Resource(),
+		InstrumentationLibrary: ro.InstrumentationScope(),
+	}
+}
+
+// Snapshot returns a read-only copy of the SpanStub.
+func (s SpanStub) Snapshot() tracesdk.ReadOnlySpan {
+	return spanSnapshot{
+		name:                 s.Name,
+		spanContext:          s.SpanContext,
+		parent:               s.Parent,
+		spanKind:             s.SpanKind,
+		startTime:            s.StartTime,
+		endTime:              s.EndTime,
+		attributes:           s.Attributes,
+		events:               s.Events,
+		links:                s.Links,
+		status:               s.Status,
+		droppedAttributes:    s.DroppedAttributes,
+		droppedEvents:        s.DroppedEvents,
+		droppedLinks:         s.DroppedLinks,
+		childSpanCount:       s.ChildSpanCount,
+		resource:             s.Resource,
+		instrumentationScope: s.InstrumentationLibrary,
+	}
+}
+
+type spanSnapshot struct {
+	// Embed the interface to implement the private method.
+	tracesdk.ReadOnlySpan
+
+	name                 string
+	spanContext          trace.SpanContext
+	parent               trace.SpanContext
+	spanKind             trace.SpanKind
+	startTime            time.Time
+	endTime              time.Time
+	attributes           []attribute.KeyValue
+	events               []tracesdk.Event
+	links                []tracesdk.Link
+	status               tracesdk.Status
+	droppedAttributes    int
+	droppedEvents        int
+	droppedLinks         int
+	childSpanCount       int
+	resource             *resource.Resource
+	instrumentationScope instrumentation.Scope
+}
+
+func (s spanSnapshot) Name() string                     { return s.name }
+func (s spanSnapshot) SpanContext() trace.SpanContext   { return s.spanContext }
+func (s spanSnapshot) Parent() trace.SpanContext        { return s.parent }
+func (s spanSnapshot) SpanKind() trace.SpanKind         { return s.spanKind }
+func (s spanSnapshot) StartTime() time.Time             { return s.startTime }
+func (s spanSnapshot) EndTime() time.Time               { return s.endTime }
+func (s spanSnapshot) Attributes() []attribute.KeyValue { return s.attributes }
+func (s spanSnapshot) Links() []tracesdk.Link           { return s.links }
+func (s spanSnapshot) Events() []tracesdk.Event         { return s.events }
+func (s spanSnapshot) Status() tracesdk.Status          { return s.status }
+func (s spanSnapshot) DroppedAttributes() int           { return s.droppedAttributes }
+func (s spanSnapshot) DroppedLinks() int                { return s.droppedLinks }
+func (s spanSnapshot) DroppedEvents() int               { return s.droppedEvents }
+func (s spanSnapshot) ChildSpanCount() int              { return s.childSpanCount }
+func (s spanSnapshot) Resource() *resource.Resource     { return s.resource }
+func (s spanSnapshot) InstrumentationScope() instrumentation.Scope {
+	return s.instrumentationScope
+}
+func (s spanSnapshot) InstrumentationLibrary() instrumentation.Library {
+	return s.instrumentationScope
+}

vendor/modules.txt

@@ -463,6 +463,7 @@ go.opentelemetry.io/otel/sdk/internal
 go.opentelemetry.io/otel/sdk/internal/env
 go.opentelemetry.io/otel/sdk/resource
 go.opentelemetry.io/otel/sdk/trace
+go.opentelemetry.io/otel/sdk/trace/tracetest
 # go.opentelemetry.io/otel/trace v1.11.1
 ## explicit; go 1.18
 go.opentelemetry.io/otel/trace