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 <[email protected]>
(cherry picked from commit 8472946)
Signed-off-by: Paweł Gronowski <[email protected]>

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"
  "go.opentelemetry.io/otel"
@@ -61,7 +62,26 @@ 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)
  },
  })
 }
@@ -100,7 +120,7 @@ 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),
@@ -126,9 +146,7 @@ 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) {
- ctx := ic.Context
- config := ic.Config.(*TraceConfig)
+func newTracer(ctx context.Context, config *TraceConfig, procs []sdktrace.SpanProcessor) (io.Closer, error) {
 
  res, err := resource.New(ctx,
  resource.WithAttributes(
@@ -145,21 +163,8 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
  sdktrace.WithResource(res),
  }
 
- ls, 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(ls))
- for id, pctx := range ls {
- p, err := pctx.Instance()
- if err != nil {
- log.G(ctx).WithError(err).Errorf("failed to initialize a tracing processor %q", id)
- continue
- }
- proc := p.(sdktrace.SpanProcessor)
+ for _, proc := range procs {
  opts = append(opts, sdktrace.WithSpanProcessor(proc))
- procs = append(procs, proc)
  }
 
  provider := sdktrace.NewTracerProvider(opts...)
@@ -175,4 +180,5 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
  }
  return nil
  }}, nil
+
 }

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:https://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:https://localhost:4318",
+ Protocol: "http/protobuf",
+ Insecure: false},
+ output: nil,
+ },
+ {
+ name: "Test invalid endpoint, expect ErrInvalidArgument error",
+ input: OTLPConfig{Endpoint: "http:https://localhost\n:4318",
+ Protocol: "http/protobuf",
+ Insecure: false},
+ output: errdefs.ErrInvalidArgument,
+ },
+ {
+ name: "Test default protocol, expect no error",
+ input: OTLPConfig{Endpoint: "http:https://localhost:4318",
+ Protocol: "",
+ Insecure: false},
+ output: nil,
+ },
+ {
+ name: "Test grpc protocol, expect no error",
+ input: OTLPConfig{Endpoint: "http:https://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:https://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()
+}