fix: panic on auto propagator (#3920)

fix: panic on auto propagator
panic: duplicate registration: "skipper-debug" [recovered, repanicked]

test: add test coverage to otel package

Signed-off-by: Sandor Szuecs <[email protected]>

Author: szuecs

otel/otel.go

@@ -181,7 +181,6 @@ func newSpanExporter(ctx context.Context, o *Options) (trace.SpanExporter, error
 		return skipperDebugSpanExporter(ctx)
 	} else {
 		log.Debugf("Configuring span exporter using environment variables")
-		autoexport.RegisterSpanExporter("skipper-debug", skipperDebugSpanExporter)
 		return autoexport.NewSpanExporter(ctx)
 	}
 }

otel/otel_test.go

@@ -2,18 +2,149 @@ package otel
 
 import (
 	"context"
+	"os"
 	"testing"
 )
 
 func TestOtel(t *testing.T) {
-	shutdown, err := Init(context.Background(), &Options{})
-	if err != nil {
-		t.Fatalf("Failed to init OTel: %v", err)
-	}
-
-	err = shutdown(context.Background())
-	if err != nil {
-		t.Fatalf("Failed to shutdown OTel: %v", err)
+	for _, tt := range []struct {
+		name      string
+		opt       *Options
+		env       map[string]string
+		errString string
+	}{
+		{
+			name: "test otel default",
+			opt:  &Options{},
+		},
+		{
+			name: "test otel initialized",
+			opt:  &Options{Initialized: true},
+		},
+		{
+			name: "test otel exporter otlp with endpoint",
+			opt: &Options{
+				TracesExporter: "otlp",
+				ExporterOtlp: ExporterOtlp{
+					Endpoint: "http://otlp-exporter.example",
+				},
+			},
+		},
+		{
+			name: "test otel exporter otlp with endpoint and protcol grpc",
+			opt: &Options{
+				TracesExporter: "otlp",
+				ExporterOtlp: ExporterOtlp{
+					Endpoint: "http://otlp-exporter.example",
+					Protocol: "grpc",
+				},
+			},
+		},
+		{
+			name: "test otel exporter otlp with endpoint and protcol http/protobuf",
+			opt: &Options{
+				TracesExporter: "otlp",
+				ExporterOtlp: ExporterOtlp{
+					Endpoint: "http://otlp-exporter.example",
+					Protocol: "http/protobuf",
+				},
+			},
+		},
+		{
+			name: "test otel exporter otlp with endpoint and protcol unknown",
+			opt: &Options{
+				TracesExporter: "otlp",
+				ExporterOtlp: ExporterOtlp{
+					Endpoint: "http://otlp-exporter.example",
+					Protocol: "unknown",
+				},
+			},
+			errString: "invalid OTLP protocol unknown - should be one of ['grpc', 'http/protobuf']",
+		},
+		{
+			name:      "test otel exporter otlp without endpoint",
+			opt:       &Options{TracesExporter: "otlp"},
+			errString: "OTLP endpoint is required",
+		},
+		{
+			name: "test otel exporter console",
+			opt:  &Options{TracesExporter: "console"},
+		},
+		{
+			name: "test otel exporter skipper-debug",
+			opt:  &Options{TracesExporter: "skipper-debug"},
+		},
+		{
+			name: "test otel exporter auto",
+			opt:  &Options{TracesExporter: "auto"},
+			env: map[string]string{
+				"OTEL_TRACES_EXPORTER": "console",
+			},
+		},
+		{
+			name: "test otel exporter auto with batchers",
+			opt: &Options{
+				TracesExporter: "auto",
+				BatchSpanProcessor: BatchSpanProcessor{
+					ScheduleDelay:      1,
+					ExportTimeout:      1,
+					MaxQueueSize:       1,
+					MaxExportBatchSize: 1,
+				},
+			},
+			env: map[string]string{
+				"OTEL_TRACES_EXPORTER": "console",
+			},
+		},
+		{
+			name: "test otel exporter console with resources",
+			opt: &Options{
+				TracesExporter: "console",
+				ResourceAttributes: map[string]string{
+					"foo": "bar",
+				},
+			},
+		},
+		{
+			name: "test otel exporter console with propagator none",
+			opt: &Options{
+				TracesExporter: "console",
+				Propagators:    []string{"none"},
+			},
+		},
+		{
+			name: "test otel exporter console with propagator baggage",
+			opt: &Options{
+				TracesExporter: "console",
+				Propagators:    []string{"baggage"},
+			},
+		}} {
+		t.Run(tt.name, func(t *testing.T) {
+			for k, v := range tt.env {
+				if err := os.Setenv(k, v); err != nil {
+					t.Fatalf("Failed to set env: %q -> %q: %v", k, v, err)
+				}
+			}
+			shutdown, err := Init(context.Background(), tt.opt)
+			if err != nil {
+				if tt.errString == "" {
+					t.Fatalf("Failed to init OTel want no error, got: %v", err)
+				} else {
+					if tt.errString != err.Error() {
+						t.Fatalf("Failed to get error want: %q, got %q", tt.errString, err.Error())
+					}
+					return
+				}
+			} else {
+				if tt.errString != "" {
+					t.Fatalf("Failed to get wanted error: %q", tt.errString)
+				}
+			}
+			err = shutdown(context.Background())
+			if err != nil {
+				t.Fatalf("Failed to shutdown OTel: %v", err)
+			}
+		})
 	}
 
 }