Add user agent header to all requests

remotes/docker/authorizer.go

@@ -31,6 +31,7 @@ import (
 
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/version"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/net/context/ctxhttp"
@@ -40,6 +41,7 @@ type dockerAuthorizer struct {
 	credentials func(string) (string, string, error)
 
 	client *http.Client
+	ua     string
 	mu     sync.Mutex
 
 	auth map[string]string
@@ -54,6 +56,7 @@ func NewAuthorizer(client *http.Client, f func(string) (string, string, error))
 	return &dockerAuthorizer{
 		credentials: f,
 		client:      client,
+		ua:          "containerd/" + version.Version,
 		auth:        map[string]string{},
 	}
 }
@@ -194,11 +197,16 @@ func (a *dockerAuthorizer) fetchTokenWithOAuth(ctx context.Context, to tokenOpti
 		form.Set("password", to.secret)
 	}
 
-	resp, err := ctxhttp.Post(
-		ctx, a.client, to.realm,
-		"application/x-www-form-urlencoded; charset=utf-8",
-		strings.NewReader(form.Encode()),
-	)
+	req, err := http.NewRequest("POST", to.realm, strings.NewReader(form.Encode()))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded; charset=utf-8")
+	if a.ua != "" {
+		req.Header.Set("User-Agent", a.ua)
+	}
+
+	resp, err := ctxhttp.Do(ctx, a.client, req)
 	if err != nil {
 		return "", err
 	}
@@ -244,6 +252,10 @@ func (a *dockerAuthorizer) fetchToken(ctx context.Context, to tokenOptions) (str
 		return "", err
 	}
 
+	if a.ua != "" {
+		req.Header.Set("User-Agent", a.ua)
+	}
+
 	reqParams := req.URL.Query()
 
 	if to.service != "" {

remotes/docker/resolver.go

@@ -111,6 +111,7 @@ type dockerResolver struct {
 	auth      Authorizer
 	host      func(string) (string, error)
 	headers   http.Header
+	uagent    string
 	plainHTTP bool
 	client    *http.Client
 	tracker   StatusTracker
@@ -135,16 +136,22 @@ func NewResolver(options ResolverOptions) remotes.Resolver {
 			ocispec.MediaTypeImageManifest,
 			ocispec.MediaTypeImageIndex, "*"}, ", "))
 	}
-	if _, ok := options.Headers["User-Agent"]; !ok {
-		options.Headers.Set("User-Agent", "containerd/"+version.Version)
+	ua := options.Headers.Get("User-Agent")
+	if ua != "" {
+		options.Headers.Del("User-Agent")
+	} else {
+		ua = "containerd/" + version.Version
 	}
+
 	if options.Authorizer == nil {
 		options.Authorizer = NewAuthorizer(options.Client, options.Credentials)
+		options.Authorizer.(*dockerAuthorizer).ua = ua
 	}
 	return &dockerResolver{
 		auth:      options.Authorizer,
 		host:      options.Host,
 		headers:   options.Headers,
+		uagent:    ua,
 		plainHTTP: options.PlainHTTP,
 		client:    options.Client,
 		tracker:   options.Tracker,
@@ -351,6 +358,7 @@ func (r *dockerResolver) Pusher(ctx context.Context, ref string) (remotes.Pusher
 type dockerBase struct {
 	refspec reference.Spec
 	base    url.URL
+	uagent  string
 
 	client *http.Client
 	auth   Authorizer
@@ -382,6 +390,7 @@ func (r *dockerResolver) base(refspec reference.Spec) (*dockerBase, error) {
 	return &dockerBase{
 		refspec: refspec,
 		base:    base,
+		uagent:  r.uagent,
 		client:  r.client,
 		auth:    r.auth,
 	}, nil
@@ -407,6 +416,7 @@ func (r *dockerBase) authorize(ctx context.Context, req *http.Request) error {
 func (r *dockerBase) doRequest(ctx context.Context, req *http.Request) (*http.Response, error) {
 	ctx = log.WithLogger(ctx, log.G(ctx).WithField("url", req.URL.String()))
 	log.G(ctx).WithField("request.headers", req.Header).WithField("request.method", req.Method).Debug("do request")
+	req.Header.Set("User-Agent", r.uagent)
 	if err := r.authorize(ctx, req); err != nil {
 		return nil, errors.Wrap(err, "failed to authorize")
 	}