Move correlation libraries out of Workhorse and into LabKit

CHANGELOG

@@ -2,6 +2,10 @@
 
 Formerly known as 'gitlab-git-http-server'.
 
+UNRELEASED
+
+- Extract correlation code out to the LabKit project !323
+
 v 7.2.0
 
 - Update CI matrix to go1.10 + go1.11 and fix ResponseWriter bugs !309

internal/correlation/base62_test.go

-package correlation
-
-import (
-	"fmt"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestReverseBase62Conversion(t *testing.T) {
-	tests := []struct {
-		n        int64
-		expected string
-	}{
-		{n: 0, expected: "0"},
-		{n: 5, expected: "5"},
-		{n: 10, expected: "a"},
-		{n: 62, expected: "01"},
-		{n: 620, expected: "0a"},
-		{n: 6200, expected: "0C1"},
-	}
-
-	for _, test := range tests {
-		t.Run(fmt.Sprintf("%d_to_%s", test.n, test.expected), func(t *testing.T) {
-			require.Equal(t, test.expected, encodeReverseBase62(test.n))
-		})
-	}
-}

internal/correlation/context_test.go

-package correlation
-
-import (
-	"context"
-	"testing"
-)
-
-func TestExtractFromContext(t *testing.T) {
-	tests := []struct {
-		name string
-		ctx  context.Context
-		want string
-	}{
-		{"nil", nil, ""},
-		{"missing", context.Background(), ""},
-		{"set", context.WithValue(context.Background(), keyCorrelationID, "CORRELATION_ID"), "CORRELATION_ID"},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := ExtractFromContext(tt.ctx); got != tt.want {
-				t.Errorf("ExtractFromContext() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestContextWithCorrelation(t *testing.T) {
-	tests := []struct {
-		name          string
-		ctx           context.Context
-		correlationID string
-		wantValue     string
-	}{
-		{
-			name:          "nil with value",
-			ctx:           nil,
-			correlationID: "CORRELATION_ID",
-			wantValue:     "CORRELATION_ID",
-		},
-		{
-			name:          "nil with empty string",
-			ctx:           nil,
-			correlationID: "",
-			wantValue:     "",
-		},
-		{
-			name:          "value",
-			ctx:           context.Background(),
-			correlationID: "CORRELATION_ID",
-			wantValue:     "CORRELATION_ID",
-		},
-		{
-			name:          "empty",
-			ctx:           context.Background(),
-			correlationID: "",
-			wantValue:     "",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got := ContextWithCorrelation(tt.ctx, tt.correlationID)
-			gotValue := got.Value(keyCorrelationID)
-			if gotValue != tt.wantValue {
-				t.Errorf("ContextWithCorrelation().Value() = %v, want %v", gotValue, tt.wantValue)
-			}
-		})
-	}
-}

internal/correlation/generator_test.go

-package correlation
-
-import (
-	"net/http"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func Test_generateRandomCorrelationID(t *testing.T) {
-	require := require.New(t)
-
-	got, err := generateRandomCorrelationID()
-	require.NoError(err)
-	require.NotEqual(got, "", "Expected a non-empty string response")
-}
-
-func Test_generatePseudorandomCorrelationID(t *testing.T) {
-	require := require.New(t)
-
-	req, err := http.NewRequest("GET", "http://example.com", nil)
-	require.NoError(err)
-
-	got := generatePseudorandomCorrelationID(req)
-	require.NotEqual(got, "", "Expected a non-empty string response")
-	require.True(strings.HasPrefix(got, "E:"), "Expected the psuedorandom correlator to have an `E:` prefix")
-}
-
-func Test_generateRandomCorrelationIDWithFallback(t *testing.T) {
-	require := require.New(t)
-
-	req, err := http.NewRequest("GET", "http://example.com", nil)
-	require.NoError(err)
-
-	got := generateRandomCorrelationIDWithFallback(req)
-	require.NotEqual(got, "", "Expected a non-empty string response")
-	require.False(strings.HasPrefix(got, "E:"), "Not expecting fallback to pseudorandom correlationID")
-}

internal/correlation/inbound_http_test.go

-package correlation
-
-import (
-	"bytes"
-	"crypto/rand"
-	"io"
-	"net/http"
-	"net/http/httptest"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestInjectCorrelationID(t *testing.T) {
-	tests := []struct {
-		name       string
-		randSource io.Reader
-	}{
-		{name: "Entropy Available", randSource: rand.Reader},
-		{name: "No Entropy", randSource: &bytes.Buffer{}},
-	}
-
-	defer func() {
-		randSource = rand.Reader
-	}()
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			invoked := false
-			randSource = test.randSource
-
-			h := InjectCorrelationID(http.HandlerFunc(func(_ http.ResponseWriter, r *http.Request) {
-				invoked = true
-
-				ctx := r.Context()
-				correlationID := ExtractFromContext(ctx)
-				require.NotNil(t, correlationID, "CorrelationID is missing")
-				require.NotEmpty(t, correlationID, "CorrelationID is missing")
-			}))
-
-			r := httptest.NewRequest("GET", "http://example.com", nil)
-			h.ServeHTTP(nil, r)
-
-			require.True(t, invoked, "handler not executed")
-		})
-	}
-}

internal/correlation/outbound_http_test.go

-package correlation
-
-import (
-	"context"
-	"errors"
-	"net/http"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-var httpCorrelationTests = []struct {
-	name          string
-	ctx           context.Context
-	correlationID string
-	hasHeader     bool
-}{
-	{
-		name:          "nil with value",
-		ctx:           nil,
-		correlationID: "CORRELATION_ID",
-		hasHeader:     true,
-	},
-	{
-		name:          "nil without value",
-		ctx:           nil,
-		correlationID: "",
-		hasHeader:     false,
-	},
-	{
-		name:          "context with value",
-		ctx:           context.Background(),
-		correlationID: "CORRELATION_ID",
-		hasHeader:     true,
-	},
-	{
-		name:          "context without value",
-		ctx:           context.Background(),
-		correlationID: "",
-		hasHeader:     false,
-	},
-}
-
-func Test_injectRequest(t *testing.T) {
-	for _, tt := range httpCorrelationTests {
-		t.Run(tt.name, func(t *testing.T) {
-			require := require.New(t)
-
-			ctx := context.WithValue(tt.ctx, keyCorrelationID, tt.correlationID)
-			req, err := http.NewRequest("GET", "http://example.com", nil)
-			require.NoError(err)
-
-			req = req.WithContext(ctx)
-
-			injectRequest(req)
-
-			value := req.Header.Get(propagationHeader)
-			require.True(tt.hasHeader == (value != ""), "Expected header existence %v. Instead got header %v", tt.hasHeader, value)
-
-			if tt.hasHeader {
-				require.Equal(tt.correlationID, value, "Expected header value %v, got %v", tt.correlationID, value)
-			}
-		})
-	}
-}
-
-type delegatedRoundTripper struct {
-	delegate func(req *http.Request) (*http.Response, error)
-}
-
-func (c delegatedRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	return c.delegate(req)
-}
-
-func roundTripperFunc(delegate func(req *http.Request) (*http.Response, error)) http.RoundTripper {
-	return &delegatedRoundTripper{delegate}
-}
-
-func TestInstrumentedRoundTripper(t *testing.T) {
-	for _, tt := range httpCorrelationTests {
-		t.Run(tt.name, func(t *testing.T) {
-			require := require.New(t)
-
-			response := &http.Response{}
-			mockTransport := roundTripperFunc(func(req *http.Request) (*http.Response, error) {
-				value := req.Header.Get(propagationHeader)
-				require.True(tt.hasHeader == (value != ""), "Expected header existence %v. Instead got header %v", tt.hasHeader, value)
-
-				if tt.hasHeader {
-					require.Equal(tt.correlationID, value, "Expected header value %v, got %v", tt.correlationID, value)
-				}
-
-				return response, nil
-			})
-
-			client := &http.Client{
-				Transport: NewInstrumentedRoundTripper(mockTransport),
-			}
-
-			ctx := context.WithValue(tt.ctx, keyCorrelationID, tt.correlationID)
-			req, err := http.NewRequest("GET", "http://example.com", nil)
-			require.NoError(err)
-
-			req = req.WithContext(ctx)
-
-			res, err := client.Do(req)
-			require.NoError(err)
-			require.Equal(response, res)
-		})
-	}
-}
-
-func TestInstrumentedRoundTripperFailures(t *testing.T) {
-	for _, tt := range httpCorrelationTests {
-		t.Run(tt.name+" - with errors", func(t *testing.T) {
-			require := require.New(t)
-
-			testErr := errors.New("test")
-
-			mockTransport := roundTripperFunc(func(req *http.Request) (*http.Response, error) {
-				value := req.Header.Get(propagationHeader)
-				require.True(tt.hasHeader == (value != ""), "Expected header existence %v. Instead got header %v", tt.hasHeader, value)
-
-				if tt.hasHeader {
-					require.Equal(tt.correlationID, value, "Expected header value %v, got %v", tt.correlationID, value)
-				}
-
-				return nil, testErr
-			})
-
-			client := &http.Client{
-				Transport: NewInstrumentedRoundTripper(mockTransport),
-			}
-
-			ctx := context.WithValue(tt.ctx, keyCorrelationID, tt.correlationID)
-			req, err := http.NewRequest("GET", "http://example.com", nil)
-			require.NoError(err)
-
-			req = req.WithContext(ctx)
-
-			res, err := client.Do(req)
-			require.Error(err)
-			require.Nil(res)
-		})
-	}
-}
-
-func TestInstrumentedRoundTripperWithoutContext(t *testing.T) {
-	require := require.New(t)
-
-	response := &http.Response{}
-	mockTransport := roundTripperFunc(func(req *http.Request) (*http.Response, error) {
-		return response, nil
-	})
-
-	client := &http.Client{
-		Transport: NewInstrumentedRoundTripper(mockTransport),
-	}
-
-	req, err := http.NewRequest("GET", "http://example.com", nil)
-	require.NoError(err)
-
-	res, err := client.Do(req)
-	require.NoError(err)
-	require.Equal(response, res)
-}

internal/correlation/raven/extras_test.go

-package raven
-
-import (
-	"context"
-	"reflect"
-	"testing"
-
-	raven "github.com/getsentry/raven-go"
-
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
-)
-
-func TestSetExtra(t *testing.T) {
-
-	tests := []struct {
-		name  string
-		ctx   context.Context
-		extra raven.Extra
-		want  raven.Extra
-	}{
-		{
-			name:  "trivial",
-			ctx:   nil,
-			extra: nil,
-			want:  raven.Extra{},
-		},
-		{
-			name: "no_context",
-			ctx:  nil,
-			extra: map[string]interface{}{
-				"key": "value",
-			},
-			want: map[string]interface{}{
-				"key": "value",
-			},
-		},
-		{
-			name: "context",
-			ctx:  correlation.ContextWithCorrelation(context.Background(), "C001"),
-			extra: map[string]interface{}{
-				"key": "value",
-			},
-			want: map[string]interface{}{
-				"key":               "value",
-				ravenSentryExtraKey: "C001",
-			},
-		},
-		{
-			name:  "no_injected_extras",
-			ctx:   correlation.ContextWithCorrelation(context.Background(), "C001"),
-			extra: nil,
-			want: map[string]interface{}{
-				ravenSentryExtraKey: "C001",
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := SetExtra(tt.ctx, tt.extra); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("SetExtra() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

internal/gitaly/gitaly.go

@@ -10,7 +10,7 @@ import (
 	gitalyclient "gitlab.com/gitlab-org/gitaly/client"
 	"google.golang.org/grpc"
 
-	grpccorrelation "gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation/grpc"
+	grpccorrelation "gitlab.com/gitlab-org/labkit/correlation/grpc"
 )
 
 type Server struct {
@@ -114,14 +114,14 @@ func newConnection(server Server) (*grpc.ClientConn, error) {
 		grpc.WithStreamInterceptor(
 			grpc_middleware.ChainStreamClient(
 				grpc_prometheus.StreamClientInterceptor,
-				grpccorrelation.StreamClientCorrelationInterceptor,
+				grpccorrelation.StreamClientCorrelationInterceptor(),
 			),
 		),
 
 		grpc.WithUnaryInterceptor(
 			grpc_middleware.ChainUnaryClient(
 				grpc_prometheus.UnaryClientInterceptor,
-				grpccorrelation.UnaryClientCorrelationInterceptor,
+				grpccorrelation.UnaryClientCorrelationInterceptor(),
 			),
 		),
 	)

internal/helper/raven.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/getsentry/raven-go"
 
-	correlation "gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation/raven"
+	correlation "gitlab.com/gitlab-org/labkit/correlation/raven"
 )
 
 var ravenHeaderBlacklist = []string{

internal/log/logrus.go

@@ -5,7 +5,7 @@ import (
 
 	"github.com/sirupsen/logrus"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
 )
 
 // Fields type, an helper to avoid importing logrus.Fields

internal/log/logrus_test.go

@@ -8,7 +8,8 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/require"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/log"
 )
 

internal/objectstore/object.go

@@ -9,7 +9,8 @@ import (
 	"net/http"
 	"time"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 )
 

internal/sendurl/sendurl.go

@@ -9,7 +9,8 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/log"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/senddata"

internal/upstream/roundtripper/roundtripper.go

@@ -8,8 +8,9 @@ import (
 	"net/url"
 	"time"
 
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/badgateway"
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
 )
 
 func mustParseAddress(address, scheme string) string {

internal/zipartifacts/open_archive.go

@@ -13,7 +13,8 @@ import (
 
 	"github.com/jfbus/httprs"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 )
 

main.go

@@ -25,8 +25,9 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
+	"gitlab.com/gitlab-org/labkit/correlation"
+
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/config"
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/log"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/queueing"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/redis"

vendor/gitlab.com/gitlab-org/labkit/LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2016-2017 GitLab B.V.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

internal/correlation/grpc/client_interceptors.go → vendor/gitlab.com/gitlab-org/labkit/correlation/grpc/client_interceptors.go

@@ -6,11 +6,9 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
 )
 
-const metadataCorrelatorKey = "X-GitLab-Correlation-ID"
-
 func injectFromContext(ctx context.Context) context.Context {
 	correlationID := correlation.ExtractFromContext(ctx)
 	if correlationID != "" {
@@ -21,13 +19,17 @@ func injectFromContext(ctx context.Context) context.Context {
 }
 
 // UnaryClientCorrelationInterceptor propagates Correlation-IDs downstream
-func UnaryClientCorrelationInterceptor(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
-	ctx = injectFromContext(ctx)
-	return invoker(ctx, method, req, reply, cc, opts...)
+func UnaryClientCorrelationInterceptor() grpc.UnaryClientInterceptor {
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		ctx = injectFromContext(ctx)
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
 }
 
 // StreamClientCorrelationInterceptor propagates Correlation-IDs downstream
-func StreamClientCorrelationInterceptor(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
-	ctx = injectFromContext(ctx)
-	return streamer(ctx, desc, cc, method, opts...)
+func StreamClientCorrelationInterceptor() grpc.StreamClientInterceptor {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		ctx = injectFromContext(ctx)
+		return streamer(ctx, desc, cc, method, opts...)
+	}
 }

vendor/gitlab.com/gitlab-org/labkit/correlation/grpc/key.go

+package grpccorrelation
+
+const metadataCorrelatorKey = "X-GitLab-Correlation-ID"

vendor/gitlab.com/gitlab-org/labkit/correlation/grpc/server_interceptors.go

+package grpccorrelation
+
+import (
+	"context"
+
+	"github.com/grpc-ecosystem/go-grpc-middleware"
+	"gitlab.com/gitlab-org/labkit/correlation"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+func extractFromContext(ctx context.Context) context.Context {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return ctx
+	}
+	values := md.Get(metadataCorrelatorKey)
+	if len(values) < 1 {
+		return ctx
+	}
+
+	return correlation.ContextWithCorrelation(ctx, values[0])
+}
+
+// UnaryServerCorrelationInterceptor propagates Correlation-IDs from incoming upstream services
+func UnaryServerCorrelationInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		ctx = extractFromContext(ctx)
+		return handler(ctx, req)
+	}
+}
+
+// StreamServerCorrelationInterceptor propagates Correlation-IDs from incoming upstream services
+func StreamServerCorrelationInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		wrapped := grpc_middleware.WrapServerStream(ss)
+		wrapped.WrappedContext = extractFromContext(ss.Context())
+
+		return handler(srv, wrapped)
+	}
+}

internal/correlation/inbound_http.go → vendor/gitlab.com/gitlab-org/labkit/correlation/inbound_http.go

@@ -5,7 +5,10 @@ import (
 )
 
 // InjectCorrelationID middleware will propagate or create a Correlation-ID for the incoming request
-func InjectCorrelationID(h http.Handler) http.Handler {
+func InjectCorrelationID(h http.Handler, opts ...InboundHandlerOption) http.Handler {
+	// Currently we don't use any of the options available
+	applyInboundHandlerOptions(opts)
+
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		parent := r.Context()
 

vendor/gitlab.com/gitlab-org/labkit/correlation/inbound_http_options.go

+package correlation
+
+// The configuration for InjectCorrelationID
+type inboundHandlerConfig struct {
+}
+
+// InboundHandlerOption will configure a correlation handler
+// currently there are no options, but this gives us the option
+// to extend the interface in a backwards compatible way
+type InboundHandlerOption func(*inboundHandlerConfig)
+
+func applyInboundHandlerOptions(opts []InboundHandlerOption) inboundHandlerConfig {
+	config := inboundHandlerConfig{}
+	for _, v := range opts {
+		v(&config)
+	}
+
+	return config
+}

internal/correlation/outbound_http.go → vendor/gitlab.com/gitlab-org/labkit/correlation/outbound_http.go

@@ -27,6 +27,9 @@ func (c instrumentedRoundTripper) RoundTrip(req *http.Request) (res *http.Respon
 // NewInstrumentedRoundTripper acts as a "client-middleware" for outbound http requests
 // adding instrumentation to the outbound request and then delegating to the underlying
 // transport
-func NewInstrumentedRoundTripper(delegate http.RoundTripper) http.RoundTripper {
+func NewInstrumentedRoundTripper(delegate http.RoundTripper, opts ...InstrumentedRoundTripperOption) http.RoundTripper {
+	// Currently we don't use any of the options available
+	applyInstrumentedRoundTripperOptions(opts)
+
 	return &instrumentedRoundTripper{delegate: delegate}
 }

vendor/gitlab.com/gitlab-org/labkit/correlation/outbound_http_options.go

+package correlation
+
+// The configuration for InjectCorrelationID
+type instrumentedRoundTripperConfig struct {
+}
+
+// InstrumentedRoundTripperOption will configure a correlation handler
+// currently there are no options, but this gives us the option
+// to extend the interface in a backwards compatible way
+type InstrumentedRoundTripperOption func(*instrumentedRoundTripperConfig)
+
+func applyInstrumentedRoundTripperOptions(opts []InstrumentedRoundTripperOption) instrumentedRoundTripperConfig {
+	config := instrumentedRoundTripperConfig{}
+	for _, v := range opts {
+		v(&config)
+	}
+
+	return config
+}

internal/correlation/raven/extras.go → vendor/gitlab.com/gitlab-org/labkit/correlation/raven/extras.go

@@ -5,7 +5,7 @@ import (
 
 	raven "github.com/getsentry/raven-go"
 
-	"gitlab.com/gitlab-org/gitlab-workhorse/internal/correlation"
+	"gitlab.com/gitlab-org/labkit/correlation"
 )
 
 const ravenSentryExtraKey = "gitlab.CorrelationID"

vendor/vendor.json

@@ -414,6 +414,30 @@
 			"version": "v0.71.0",
 			"versionExact": "v0.71.0"
 		},
+		{
+			"checksumSHA1": "S9x46Eq79I1EkoXI8woeIU6w/wY=",
+			"path": "gitlab.com/gitlab-org/labkit/correlation",
+			"revision": "fb2eeb11fc358f8f538692d1c0f6e57d7f268691",
+			"revisionTime": "2018-11-21T15:01:09Z",
+			"version": "master",
+			"versionExact": "master"
+		},
+		{
+			"checksumSHA1": "UFBFulprWZHuL9GHhjCKoHXm+Ww=",
+			"path": "gitlab.com/gitlab-org/labkit/correlation/grpc",
+			"revision": "fb2eeb11fc358f8f538692d1c0f6e57d7f268691",
+			"revisionTime": "2018-11-21T15:01:09Z",
+			"version": "master",
+			"versionExact": "master"
+		},
+		{
+			"checksumSHA1": "YyeJ2t/STDZj3X4xetPzTC0I9hU=",
+			"path": "gitlab.com/gitlab-org/labkit/correlation/raven",
+			"revision": "fb2eeb11fc358f8f538692d1c0f6e57d7f268691",
+			"revisionTime": "2018-11-21T15:01:09Z",
+			"version": "master",
+			"versionExact": "master"
+		},
 		{
 			"checksumSHA1": "BGm8lKZmvJbf/YOJLeL1rw2WVjA=",
 			"path": "golang.org/x/crypto/ssh/terminal",