Use http.NewRequestWithContext for outgoing HTTP requests

This simple change mainly affects the distribution client. By respecting
the context the caller passes in, timeouts and cancellations will work
as expected. Also, transports which rely on the context (such as tracing
transports that retrieve a span from the context) will work properly.

Signed-off-by: Aaron Lehmann <alehmann@netflix.com>

registry/client/auth/session.go

@@ -1,6 +1,7 @@
 package auth
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -258,7 +259,7 @@ func (th *tokenHandler) AuthorizeRequest(req *http.Request, params map[string]st
 		}.String())
 	}
 
-	token, err := th.getToken(params, additionalScopes...)
+	token, err := th.getToken(req.Context(), params, additionalScopes...)
 	if err != nil {
 		return err
 	}
@@ -268,7 +269,7 @@ func (th *tokenHandler) AuthorizeRequest(req *http.Request, params map[string]st
 	return nil
 }
 
-func (th *tokenHandler) getToken(params map[string]string, additionalScopes ...string) (string, error) {
+func (th *tokenHandler) getToken(ctx context.Context, params map[string]string, additionalScopes ...string) (string, error) {
 	th.tokenLock.Lock()
 	defer th.tokenLock.Unlock()
 	scopes := make([]string, 0, len(th.scopes)+len(additionalScopes))
@@ -286,7 +287,7 @@ func (th *tokenHandler) getToken(params map[string]string, additionalScopes ...s
 
 	now := th.clock.Now()
 	if now.After(th.tokenExpiration) || addedScopes {
-		token, expiration, err := th.fetchToken(params, scopes)
+		token, expiration, err := th.fetchToken(ctx, params, scopes)
 		if err != nil {
 			return "", err
 		}
@@ -320,7 +321,7 @@ type postTokenResponse struct {
 	Scope        string    `json:"scope"`
 }
 
-func (th *tokenHandler) fetchTokenWithOAuth(realm *url.URL, refreshToken, service string, scopes []string) (token string, expiration time.Time, err error) {
+func (th *tokenHandler) fetchTokenWithOAuth(ctx context.Context, realm *url.URL, refreshToken, service string, scopes []string) (token string, expiration time.Time, err error) {
 	form := url.Values{}
 	form.Set("scope", strings.Join(scopes, " "))
 	form.Set("service", service)
@@ -348,7 +349,12 @@ func (th *tokenHandler) fetchTokenWithOAuth(realm *url.URL, refreshToken, servic
 		return "", time.Time{}, fmt.Errorf("no supported grant type")
 	}
 
-	resp, err := th.client().PostForm(realm.String(), form)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, realm.String(), strings.NewReader(form.Encode()))
+	if err != nil {
+		return "", time.Time{}, err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	resp, err := th.client().Do(req)
 	if err != nil {
 		return "", time.Time{}, err
 	}
@@ -396,9 +402,8 @@ type getTokenResponse struct {
 	RefreshToken string    `json:"refresh_token"`
 }
 
-func (th *tokenHandler) fetchTokenWithBasicAuth(realm *url.URL, service string, scopes []string) (token string, expiration time.Time, err error) {
-
-	req, err := http.NewRequest("GET", realm.String(), nil)
+func (th *tokenHandler) fetchTokenWithBasicAuth(ctx context.Context, realm *url.URL, service string, scopes []string) (token string, expiration time.Time, err error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, realm.String(), nil)
 	if err != nil {
 		return "", time.Time{}, err
 	}
@@ -479,7 +484,7 @@ func (th *tokenHandler) fetchTokenWithBasicAuth(realm *url.URL, service string,
 	return tr.Token, tr.IssuedAt.Add(time.Duration(tr.ExpiresIn) * time.Second), nil
 }
 
-func (th *tokenHandler) fetchToken(params map[string]string, scopes []string) (token string, expiration time.Time, err error) {
+func (th *tokenHandler) fetchToken(ctx context.Context, params map[string]string, scopes []string) (token string, expiration time.Time, err error) {
 	realm, ok := params["realm"]
 	if !ok {
 		return "", time.Time{}, errors.New("no realm specified for token auth challenge")
@@ -500,10 +505,10 @@ func (th *tokenHandler) fetchToken(params map[string]string, scopes []string) (t
 	}
 
 	if refreshToken != "" || th.forceOAuth {
-		return th.fetchTokenWithOAuth(realmURL, refreshToken, service, scopes)
+		return th.fetchTokenWithOAuth(ctx, realmURL, refreshToken, service, scopes)
 	}
 
-	return th.fetchTokenWithBasicAuth(realmURL, service, scopes)
+	return th.fetchTokenWithBasicAuth(ctx, realmURL, service, scopes)
 }
 
 type basicHandler struct {

registry/client/blob_writer.go

@@ -13,6 +13,8 @@ import (
 )
 
 type httpBlobUpload struct {
+	ctx context.Context
+
 	statter distribution.BlobStatter
 	client  *http.Client
 
@@ -36,7 +38,7 @@ func (hbu *httpBlobUpload) handleErrorResponse(resp *http.Response) error {
 }
 
 func (hbu *httpBlobUpload) ReadFrom(r io.Reader) (n int64, err error) {
-	req, err := http.NewRequest("PATCH", hbu.location, ioutil.NopCloser(r))
+	req, err := http.NewRequestWithContext(hbu.ctx, "PATCH", hbu.location, ioutil.NopCloser(r))
 	if err != nil {
 		return 0, err
 	}
@@ -69,7 +71,7 @@ func (hbu *httpBlobUpload) ReadFrom(r io.Reader) (n int64, err error) {
 }
 
 func (hbu *httpBlobUpload) Write(p []byte) (n int, err error) {
-	req, err := http.NewRequest("PATCH", hbu.location, bytes.NewReader(p))
+	req, err := http.NewRequestWithContext(hbu.ctx, "PATCH", hbu.location, bytes.NewReader(p))
 	if err != nil {
 		return 0, err
 	}
@@ -117,7 +119,7 @@ func (hbu *httpBlobUpload) StartedAt() time.Time {
 
 func (hbu *httpBlobUpload) Commit(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
 	// TODO(dmcgowan): Check if already finished, if so just fetch
-	req, err := http.NewRequest("PUT", hbu.location, nil)
+	req, err := http.NewRequestWithContext(hbu.ctx, "PUT", hbu.location, nil)
 	if err != nil {
 		return distribution.Descriptor{}, err
 	}
@@ -140,7 +142,7 @@ func (hbu *httpBlobUpload) Commit(ctx context.Context, desc distribution.Descrip
 }
 
 func (hbu *httpBlobUpload) Cancel(ctx context.Context) error {
-	req, err := http.NewRequest("DELETE", hbu.location, nil)
+	req, err := http.NewRequestWithContext(hbu.ctx, "DELETE", hbu.location, nil)
 	if err != nil {
 		return err
 	}

registry/client/blob_writer_test.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"net/http"
 	"testing"
@@ -126,6 +127,7 @@ func TestUploadReadFrom(t *testing.T) {
 	defer c()
 
 	blobUpload := &httpBlobUpload{
+		ctx:    context.Background(),
 		client: &http.Client{},
 	}
 
@@ -265,6 +267,7 @@ func TestUploadSize(t *testing.T) {
 
 	// Writing with ReadFrom
 	blobUpload := &httpBlobUpload{
+		ctx:      context.Background(),
 		client:   &http.Client{},
 		location: e + readFromLocationPath,
 	}
@@ -284,6 +287,7 @@ func TestUploadSize(t *testing.T) {
 
 	// Writing with Write
 	blobUpload = &httpBlobUpload{
+		ctx:      context.Background(),
 		client:   &http.Client{},
 		location: e + writeLocationPath,
 	}
@@ -409,6 +413,7 @@ func TestUploadWrite(t *testing.T) {
 	defer c()
 
 	blobUpload := &httpBlobUpload{
+		ctx:    context.Background(),
 		client: &http.Client{},
 	}
 

registry/client/repository.go

@@ -118,9 +118,7 @@ func (r *registry) Repositories(ctx context.Context, entries []string, last stri
 			return 0, err
 		}
 
-		for cnt := range ctlg.Repositories {
-			entries[cnt] = ctlg.Repositories[cnt]
-		}
+		copy(entries, ctlg.Repositories)
 		numFilled = len(ctlg.Repositories)
 
 		link := resp.Header.Get("Link")
@@ -373,7 +371,7 @@ func (t *tags) Untag(ctx context.Context, tag string) error {
 		return err
 	}
 
-	req, err := http.NewRequest("DELETE", u, nil)
+	req, err := http.NewRequestWithContext(ctx, "DELETE", u, nil)
 	if err != nil {
 		return err
 	}
@@ -792,7 +790,7 @@ func (bs *blobs) Create(ctx context.Context, options ...distribution.BlobCreateO
 		return nil, err
 	}
 
-	req, err := http.NewRequest("POST", u, nil)
+	req, err := http.NewRequestWithContext(ctx, "POST", u, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -827,6 +825,7 @@ func (bs *blobs) Create(ctx context.Context, options ...distribution.BlobCreateO
 		}
 
 		return &httpBlobUpload{
+			ctx:       ctx,
 			statter:   bs.statter,
 			client:    bs.client,
 			uuid:      uuid,
@@ -845,6 +844,7 @@ func (bs *blobs) Resume(ctx context.Context, id string) (distribution.BlobWriter
 	}
 
 	return &httpBlobUpload{
+		ctx:       ctx,
 		statter:   bs.statter,
 		client:    bs.client,
 		uuid:      id,