envoy: Enable zipkin tracing (#737)

- Update envoy bootstrap config to protobufs
- Reorganize tracing config to avoid cyclic import
- Push down zipkin config to Envoy
- Update tracing options to provide sample rate

internal/telemetry/trace/trace.go

@@ -10,47 +10,18 @@ import (
 	zipkinHTTP "github.com/openzipkin/zipkin-go/reporter/http"
 	"go.opencensus.io/trace"
 
+	"github.com/pomerium/pomerium/config"
 	"github.com/pomerium/pomerium/internal/log"
 )
 
-const (
-	// JaegerTracingProviderName is the name of the tracing provider Jaeger.
-	JaegerTracingProviderName = "jaeger"
-	// ZipkinTracingProviderName is the name of the tracing provider Zipkin.
-	ZipkinTracingProviderName = "zipkin"
-)
-
-// TracingOptions contains the configurations settings for a http server.
-type TracingOptions struct {
-	// Shared
-	Provider string
-	Service  string
-	Debug    bool
-
-	// Jaeger
-
-	// CollectorEndpoint is the full url to the Jaeger HTTP Thrift collector.
-	// For example, http://localhost:14268/api/traces
-	JaegerCollectorEndpoint string `mapstructure:"tracing_jaeger_collector_endpoint"`
-	// AgentEndpoint instructs exporter to send spans to jaeger-agent at this address.
-	// For example, localhost:6831.
-	JaegerAgentEndpoint string `mapstructure:"tracing_jaeger_agent_endpoint"`
-
-	// Zipkin
-
-	// ZipkinEndpoint configures the zipkin collector URI
-	// Example: http://zipkin:9411/api/v2/spans
-	ZipkinEndpoint string `mapstructure:"tracing_zipkin_endpoint"`
-}
-
 // RegisterTracing creates a new trace exporter from TracingOptions.
-func RegisterTracing(opts *TracingOptions) (trace.Exporter, error) {
+func RegisterTracing(opts *config.TracingOptions) (trace.Exporter, error) {
 	var exporter trace.Exporter
 	var err error
 	switch opts.Provider {
-	case JaegerTracingProviderName:
+	case config.JaegerTracingProviderName:
 		exporter, err = registerJaeger(opts)
-	case ZipkinTracingProviderName:
+	case config.ZipkinTracingProviderName:
 		exporter, err = registerZipkin(opts)
 	default:
 		return nil, fmt.Errorf("telemetry/trace: provider %s unknown", opts.Provider)
@@ -58,10 +29,8 @@ func RegisterTracing(opts *TracingOptions) (trace.Exporter, error) {
 	if err != nil {
 		return nil, err
 	}
-	if opts.Debug {
-		log.Debug().Msg("telemetry/trace: debug on, sample everything")
-		trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
-	}
+	trace.ApplyConfig(trace.Config{DefaultSampler: trace.ProbabilitySampler(opts.SampleRate)})
+
 	log.Debug().Interface("Opts", opts).Msg("telemetry/trace: exporter created")
 	return exporter, nil
 }
@@ -71,13 +40,15 @@ func UnregisterTracing(exporter trace.Exporter) {
 	trace.UnregisterExporter(exporter)
 }
 
-func registerJaeger(opts *TracingOptions) (trace.Exporter, error) {
-	jex, err := jaeger.NewExporter(
-		jaeger.Options{
-			AgentEndpoint:     opts.JaegerAgentEndpoint,
-			CollectorEndpoint: opts.JaegerCollectorEndpoint,
-			ServiceName:       opts.Service,
-		})
+func registerJaeger(opts *config.TracingOptions) (trace.Exporter, error) {
+	jOpts := jaeger.Options{
+		ServiceName:   opts.Service,
+		AgentEndpoint: opts.JaegerAgentEndpoint,
+	}
+	if opts.JaegerCollectorEndpoint != nil {
+		jOpts.CollectorEndpoint = opts.JaegerCollectorEndpoint.String()
+	}
+	jex, err := jaeger.NewExporter(jOpts)
 	if err != nil {
 		return nil, err
 	}
@@ -85,13 +56,13 @@ func registerJaeger(opts *TracingOptions) (trace.Exporter, error) {
 	return jex, nil
 }
 
-func registerZipkin(opts *TracingOptions) (trace.Exporter, error) {
+func registerZipkin(opts *config.TracingOptions) (trace.Exporter, error) {
 	localEndpoint, err := zipkin.NewEndpoint(opts.Service, "")
 	if err != nil {
 		return nil, fmt.Errorf("telemetry/trace: could not create local endpoint: %w", err)
 	}
 
-	reporter := zipkinHTTP.NewReporter(opts.ZipkinEndpoint)
+	reporter := zipkinHTTP.NewReporter(opts.ZipkinEndpoint.String())
 
 	exporter := ocZipkin.NewExporter(reporter, localEndpoint)
 	trace.RegisterExporter(exporter)

internal/telemetry/trace/trace_test.go

@@ -1,17 +1,23 @@
 package trace
 
-import "testing"
+import (
+	"net/url"
+	"testing"
+
+	"github.com/pomerium/pomerium/config"
+)
 
 func TestRegisterTracing(t *testing.T) {
 	tests := []struct {
 		name    string
-		opts    *TracingOptions
+		opts    *config.TracingOptions
 		wantErr bool
 	}{
-		{"jaeger", &TracingOptions{JaegerAgentEndpoint: "localhost:6831", Service: "all", Provider: "jaeger"}, false},
-		{"jaeger with debug", &TracingOptions{JaegerAgentEndpoint: "localhost:6831", Service: "all", Provider: "jaeger", Debug: true}, false},
-		{"jaeger no endpoint", &TracingOptions{JaegerAgentEndpoint: "", Service: "all", Provider: "jaeger"}, true},
-		{"unknown provider", &TracingOptions{JaegerAgentEndpoint: "localhost:0", Service: "all", Provider: "Lucius Cornelius Sulla"}, true},
+		{"jaeger", &config.TracingOptions{JaegerAgentEndpoint: "localhost:6831", Service: "all", Provider: "jaeger"}, false},
+		{"jaeger with debug", &config.TracingOptions{JaegerAgentEndpoint: "localhost:6831", Service: "all", Provider: "jaeger", Debug: true}, false},
+		{"jaeger no endpoint", &config.TracingOptions{JaegerAgentEndpoint: "", Service: "all", Provider: "jaeger"}, true},
+		{"unknown provider", &config.TracingOptions{JaegerAgentEndpoint: "localhost:0", Service: "all", Provider: "Lucius Cornelius Sulla"}, true},
+		{"zipkin with debug", &config.TracingOptions{ZipkinEndpoint: &url.URL{Host: "localhost"}, Service: "all", Provider: "zipkin", Debug: true}, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {