Add TLS option to opencensus exporter (#457)

* Add TLS option to opencensus exporter

* Fix go.mod to require newer ocagent-exporter

* Update readme

Author: Steven Karis

README.md

@@ -154,6 +154,7 @@ exporters:
   opencensus:
     headers: {"X-test-header": "test-header"}
     compression: "gzip"
+    cert-pem-file: "server_ca_public.pem" # optional to enable TLS
     endpoint: "127.0.0.1:55678"
 
   jaeger:

exporter/opencensusexporter/opencensus.go

@@ -16,11 +16,13 @@ package opencensusexporter
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"sync/atomic"
 
 	"contrib.go.opencensus.io/exporter/ocagent"
 	"github.com/spf13/viper"
+	"google.golang.org/grpc/credentials"
 
 	agenttracepb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/trace/v1"
 	"github.com/census-instrumentation/opencensus-service/data"
@@ -34,8 +36,10 @@ type opencensusConfig struct {
 	Endpoint    string            `mapstructure:"endpoint,omitempty"`
 	Compression string            `mapstructure:"compression,omitempty"`
 	Headers     map[string]string `mapstructure:"headers,omitempty"`
+	NumWorkers  int               `mapstructure:"num-workers,omitempty"`
+	CertPemFile string            `mapstructure:"cert-pem-file,omitempty"`
+
 	// TODO: add insecure, service name options.
-	NumWorkers int `mapstructure:"num-workers,omitempty"`
 }
 
 type ocagentExporter struct {
@@ -47,6 +51,15 @@ const (
 	defaultNumWorkers int = 2
 )
 
+var (
+	// ErrEndpointRequired indicates that this exporter was not provided with an endpoint in its config.
+	ErrEndpointRequired = errors.New("OpenCensus exporter config requires an Endpoint")
+	// ErrUnsupportedCompressionType indicates that this exporter was provided with a compression protocol it does not support.
+	ErrUnsupportedCompressionType = errors.New("OpenCensus exporter unsupported compression type")
+	// ErrUnableToGetTLSCreds indicates that this exporter could not read the provided TLS credentials.
+	ErrUnableToGetTLSCreds = errors.New("OpenCensus exporter unable to read TLS credentials")
+)
+
 var _ processor.TraceDataProcessor = (*ocagentExporter)(nil)
 
 // OpenCensusTraceExportersFromViper unmarshals the viper and returns an processor.TraceDataProcessor targeting
@@ -64,16 +77,25 @@ func OpenCensusTraceExportersFromViper(v *viper.Viper) (tdps []processor.TraceDa
 	}
 
 	if ocac.Endpoint == "" {
-		return nil, nil, nil, fmt.Errorf("openCensus config requires an Endpoint")
+		return nil, nil, nil, ErrEndpointRequired
 	}
 
-	opts := []ocagent.ExporterOption{ocagent.WithAddress(ocac.Endpoint), ocagent.WithInsecure()}
+	opts := []ocagent.ExporterOption{ocagent.WithAddress(ocac.Endpoint)}
 	if ocac.Compression != "" {
 		if compressionKey := grpc.GetGRPCCompressionKey(ocac.Compression); compressionKey != compression.Unsupported {
 			opts = append(opts, ocagent.UseCompressor(compressionKey))
 		} else {
-			return nil, nil, nil, fmt.Errorf("unsupported compression type: %s", ocac.Compression)
+			return nil, nil, nil, ErrUnsupportedCompressionType
+		}
+	}
+	if ocac.CertPemFile != "" {
+		creds, err := credentials.NewClientTLSFromFile(ocac.CertPemFile, "")
+		if err != nil {
+			return nil, nil, nil, ErrUnableToGetTLSCreds
 		}
+		opts = append(opts, ocagent.WithTLSCredentials(creds))
+	} else {
+		opts = append(opts, ocagent.WithInsecure())
 	}
 	if len(ocac.Headers) > 0 {
 		opts = append(opts, ocagent.WithHeaders(ocac.Headers))

exporter/opencensusexporter/opencensusexporter_test.go

@@ -14,4 +14,67 @@
 
 package opencensusexporter
 
-// TODO: Add tests.
+import (
+	"testing"
+
+	"github.com/spf13/viper"
+)
+
+func TestOpenCensusTraceExportersFromViper(t *testing.T) {
+	v := viper.New()
+	v.Set("opencensus", struct{}{})
+	_, _, _, err := OpenCensusTraceExportersFromViper(v)
+
+	if err != ErrEndpointRequired {
+		t.Fatalf("Expected to get ErrEndpointRequired but did not")
+	}
+
+	v.Set("opencensus.endpoint", "127.0.0.1:55678")
+	exporters, _, _, err := OpenCensusTraceExportersFromViper(v)
+
+	if err != nil {
+		t.Fatalf("Unexpected error building OpenCensus Exporter")
+	}
+	if len(exporters) != 1 {
+		t.Fatalf("Should get 1 exporter but got %d", len(exporters))
+	}
+}
+
+func TestOpenCensusTraceExportersFromViper_TLS(t *testing.T) {
+	v := viper.New()
+	v.Set("opencensus.endpoint", "127.0.0.1:55678")
+	v.Set("opencensus.cert-pem-file", "dummy_file.pem")
+	_, _, _, err := OpenCensusTraceExportersFromViper(v)
+
+	if err != ErrUnableToGetTLSCreds {
+		t.Fatalf("Expected to get ErrUnableToGetTLSCreds but did not")
+	}
+
+	v.Set("opencensus.cert-pem-file", "testdata/test_cert.pem")
+	exporters, _, _, err := OpenCensusTraceExportersFromViper(v)
+	if err != nil {
+		t.Fatalf("Unexpected error building OpenCensus Exporter")
+	}
+	if len(exporters) != 1 {
+		t.Fatalf("Should get 1 exporter but got %d", len(exporters))
+	}
+}
+
+func TestOpenCensusTraceExportersFromViper_Compression(t *testing.T) {
+	v := viper.New()
+	v.Set("opencensus.endpoint", "127.0.0.1:55678")
+	v.Set("opencensus.compression", "random-compression")
+	_, _, _, err := OpenCensusTraceExportersFromViper(v)
+	if err != ErrUnsupportedCompressionType {
+		t.Fatalf("Expected to get ErrUnsupportedCompressionType but did not")
+	}
+
+	v.Set("opencensus.compression", "gzip")
+	exporters, _, _, err := OpenCensusTraceExportersFromViper(v)
+	if err != nil {
+		t.Fatalf("Unexpected error building OpenCensus Exporter")
+	}
+	if len(exporters) != 1 {
+		t.Fatalf("Should get 1 exporter but got %d", len(exporters))
+	}
+}

exporter/opencensusexporter/testdata/test_cert.pem

@@ -0,0 +1,29 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

go.mod

@@ -3,7 +3,7 @@ module github.com/census-instrumentation/opencensus-service
 require (
 	cloud.google.com/go v0.32.0 // indirect
 	contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0
-	contrib.go.opencensus.io/exporter/ocagent v0.4.4
+	contrib.go.opencensus.io/exporter/ocagent v0.4.6
 	contrib.go.opencensus.io/exporter/stackdriver v0.9.1
 	git.apache.org/thrift.git v0.0.0-20181101003639-92be4f312b88 // indirect
 	github.com/Azure/azure-sdk-for-go v6.0.0-beta+incompatible // indirect

go.sum

@@ -8,6 +8,8 @@ contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0 h1:YsbW
 contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0/go.mod h1:uu1P0UCM/6RbsMrgPa98ll8ZcHM858i/AD06a9aLRCA=
 contrib.go.opencensus.io/exporter/ocagent v0.4.4 h1:6v7OlUmiBDhvbYcHPWp8LHO8wh9jJY8f4mO34J4GJiA=
 contrib.go.opencensus.io/exporter/ocagent v0.4.4/go.mod h1:YuG83h+XWwqWjvCqn7vK4KSyLKhThY3+gNGQ37iS2V0=
+contrib.go.opencensus.io/exporter/ocagent v0.4.6 h1:xVeoJwnzMbseoL9YWhohR6SN/GncvP1p/fznasLkT/E=
+contrib.go.opencensus.io/exporter/ocagent v0.4.6/go.mod h1:YuG83h+XWwqWjvCqn7vK4KSyLKhThY3+gNGQ37iS2V0=
 contrib.go.opencensus.io/exporter/stackdriver v0.9.1 h1:W6APgQ9we4BH8U8bnq/FvwLKo2WSMHuiMkkS/Slkg30=
 contrib.go.opencensus.io/exporter/stackdriver v0.9.1/go.mod h1:hNe5qQofPbg6bLQY5wHCvQ7o+2E5P8PkegEuQ+MyRw0=
 git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999 h1:sihTnRgTOUSCQz0iS0pjZuFQy/z7GXCJgSBg3+rZKHw=