Use golang.org/x/net/context in api/server/

This patch removes the internal context package and uses golang's
package instead.

Signed-off-by: Tibor Vass <tibor@docker.com>

api/server/auth.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/cliconfig"
-	"github.com/docker/docker/context"
+	"golang.org/x/net/context"
 )
 
 func (s *Server) postAuth(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

api/server/container.go

@@ -9,19 +9,17 @@ import (
 	"syscall"
 	"time"
 
-	"golang.org/x/net/websocket"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/daemon"
 	derr "github.com/docker/docker/errors"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/signal"
-	"github.com/docker/docker/pkg/version"
 	"github.com/docker/docker/runconfig"
 	"github.com/docker/docker/utils"
+	"golang.org/x/net/context"
+	"golang.org/x/net/websocket"
 )
 
 func (s *Server) getContainersJSON(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
@@ -75,12 +73,11 @@ func (s *Server) getContainersStats(ctx context.Context, w http.ResponseWriter,
 		closeNotifier = notifier.CloseNotify()
 	}
 
-	version, _ := ctx.Value("api-version").(version.Version)
 	config := &daemon.ContainerStatsConfig{
 		Stream:    stream,
 		OutStream: out,
 		Stop:      closeNotifier,
-		Version:   version,
+		Version:   versionFromContext(ctx),
 	}
 
 	return s.daemon.ContainerStats(vars["name"], config)
@@ -234,7 +231,7 @@ func (s *Server) postContainersKill(ctx context.Context, w http.ResponseWriter,
 		// Return error that's not caused because the container is stopped.
 		// Return error if the container is not running and the api is >= 1.20
 		// to keep backwards compatibility.
-		version := ctx.Version()
+		version := versionFromContext(ctx)
 		if version.GreaterThanOrEqualTo("1.20") || !isStopped {
 			return fmt.Errorf("Cannot kill container %s: %v", name, err)
 		}
@@ -373,7 +370,7 @@ func (s *Server) postContainersCreate(ctx context.Context, w http.ResponseWriter
 	if err != nil {
 		return err
 	}
-	version := ctx.Version()
+	version := versionFromContext(ctx)
 	adjustCPUShares := version.LessThan("1.19")
 
 	ccr, err := s.daemon.ContainerCreate(name, config, hostConfig, adjustCPUShares)

api/server/copy.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/context"
+	"golang.org/x/net/context"
 )
 
 // postContainersCopy is deprecated in favor of getContainersArchive.

api/server/daemon.go

@@ -12,12 +12,12 @@ import (
 	"github.com/docker/docker/api"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/autogen/dockerversion"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/jsonmessage"
 	"github.com/docker/docker/pkg/parsers/filters"
 	"github.com/docker/docker/pkg/parsers/kernel"
 	"github.com/docker/docker/utils"
+	"golang.org/x/net/context"
 )
 
 func (s *Server) getVersion(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
@@ -31,7 +31,7 @@ func (s *Server) getVersion(ctx context.Context, w http.ResponseWriter, r *http.
 		BuildTime:  dockerversion.BUILDTIME,
 	}
 
-	version := ctx.Version()
+	version := versionFromContext(ctx)
 
 	if version.GreaterThanOrEqualTo("1.19") {
 		v.Experimental = utils.ExperimentalBuild()

api/server/exec.go

@@ -9,9 +9,9 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/pkg/stdcopy"
 	"github.com/docker/docker/runconfig"
+	"golang.org/x/net/context"
 )
 
 func (s *Server) getExecByID(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

api/server/image.go

@@ -13,7 +13,6 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/builder"
 	"github.com/docker/docker/cliconfig"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/graph"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/parsers"
@@ -21,6 +20,7 @@ import (
 	"github.com/docker/docker/pkg/ulimit"
 	"github.com/docker/docker/runconfig"
 	"github.com/docker/docker/utils"
+	"golang.org/x/net/context"
 )
 
 func (s *Server) postCommit(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
@@ -35,7 +35,7 @@ func (s *Server) postCommit(ctx context.Context, w http.ResponseWriter, r *http.
 	cname := r.Form.Get("container")
 
 	pause := boolValue(r, "pause")
-	version := ctx.Version()
+	version := versionFromContext(ctx)
 	if r.FormValue("pause") == "" && version.GreaterThanOrEqualTo("1.13") {
 		pause = true
 	}
@@ -282,7 +282,7 @@ func (s *Server) postBuild(ctx context.Context, w http.ResponseWriter, r *http.R
 
 	w.Header().Set("Content-Type", "application/json")
 
-	version := ctx.Version()
+	version := versionFromContext(ctx)
 	if boolValue(r, "forcerm") && version.GreaterThanOrEqualTo("1.12") {
 		buildConfig.Remove = true
 	} else if r.FormValue("rm") == "" && version.GreaterThanOrEqualTo("1.12") {

api/server/inspect.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/docker/docker/context"
+	"golang.org/x/net/context"
 )
 
 // getContainersByName inspects containers configuration and serializes it as json.
@@ -16,7 +16,7 @@ func (s *Server) getContainersByName(ctx context.Context, w http.ResponseWriter,
 	var json interface{}
 	var err error
 
-	version := ctx.Version()
+	version := versionFromContext(ctx)
 
 	switch {
 	case version.LessThan("1.20"):

api/server/middleware.go

@@ -8,12 +8,14 @@ import (
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api"
 	"github.com/docker/docker/autogen/dockerversion"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/errors"
-	"github.com/docker/docker/pkg/stringid"
 	"github.com/docker/docker/pkg/version"
+	"golang.org/x/net/context"
 )
 
+// apiVersionKey is the client's requested API version.
+const apiVersionKey = "api-version"
+
 // middleware is an adapter to allow the use of ordinary functions as Docker API filters.
 // Any function that has the appropriate signature can be register as a middleware.
 type middleware func(handler HTTPAPIFunc) HTTPAPIFunc
@@ -28,16 +30,6 @@ func (s *Server) loggingMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
 	}
 }
 
-// requestIDMiddleware generates a uniq ID for each request.
-// This ID travels inside the context for tracing purposes.
-func requestIDMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
-	return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-		reqID := stringid.TruncateID(stringid.GenerateNonCryptoID())
-		ctx = context.WithValue(ctx, context.RequestID, reqID)
-		return handler(ctx, w, r, vars)
-	}
-}
-
 // userAgentMiddleware checks the User-Agent header looking for a valid docker client spec.
 func (s *Server) userAgentMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
 	return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
@@ -93,7 +85,7 @@ func versionMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
 		}
 
 		w.Header().Set("Server", "Docker/"+dockerversion.VERSION+" ("+runtime.GOOS+")")
-		ctx = context.WithValue(ctx, context.APIVersion, apiVersion)
+		ctx = context.WithValue(ctx, apiVersionKey, apiVersion)
 		return handler(ctx, w, r, vars)
 	}
 }
@@ -104,7 +96,6 @@ func versionMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
 //
 // Example: handleWithGlobalMiddlewares(s.getContainersName)
 //
-// requestIDMiddlware(
 //	s.loggingMiddleware(
 //		s.userAgentMiddleware(
 //			s.corsMiddleware(
@@ -112,14 +103,12 @@ func versionMiddleware(handler HTTPAPIFunc) HTTPAPIFunc {
 //			)
 //		)
 //	)
-// )
 func (s *Server) handleWithGlobalMiddlewares(handler HTTPAPIFunc) HTTPAPIFunc {
 	middlewares := []middleware{
 		versionMiddleware,
 		s.corsMiddleware,
 		s.userAgentMiddleware,
 		s.loggingMiddleware,
-		requestIDMiddleware,
 	}
 
 	h := handler
@@ -128,3 +117,16 @@ func (s *Server) handleWithGlobalMiddlewares(handler HTTPAPIFunc) HTTPAPIFunc {
 	}
 	return h
 }
+
+// versionFromContext returns an API version from the context using apiVersionKey.
+// It panics if the context value does not have version.Version type.
+func versionFromContext(ctx context.Context) (ver version.Version) {
+	if ctx == nil {
+		return
+	}
+	val := ctx.Value(apiVersionKey)
+	if val == nil {
+		return
+	}
+	return val.(version.Version)
+}

api/server/middleware_test.go

@@ -6,13 +6,13 @@ import (
 	"testing"
 
 	"github.com/docker/distribution/registry/api/errcode"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/errors"
+	"golang.org/x/net/context"
 )
 
 func TestVersionMiddleware(t *testing.T) {
 	handler := func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-		if ctx.Version() == "" {
+		if versionFromContext(ctx) == "" {
 			t.Fatalf("Expected version, got empty string")
 		}
 		return nil
@@ -30,7 +30,7 @@ func TestVersionMiddleware(t *testing.T) {
 
 func TestVersionMiddlewareWithErrors(t *testing.T) {
 	handler := func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-		if ctx.Version() == "" {
+		if versionFromContext(ctx) == "" {
 			t.Fatalf("Expected version, got empty string")
 		}
 		return nil
@@ -54,21 +54,3 @@ func TestVersionMiddlewareWithErrors(t *testing.T) {
 		t.Fatalf("Expected ErrorCodeNewerClientVersion, got %v", err)
 	}
 }
-
-func TestRequestIDMiddleware(t *testing.T) {
-	handler := func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-		if ctx.RequestID() == "" {
-			t.Fatalf("Expected request-id, got empty string")
-		}
-		return nil
-	}
-
-	h := requestIDMiddleware(handler)
-
-	req, _ := http.NewRequest("GET", "/containers/json", nil)
-	resp := httptest.NewRecorder()
-	ctx := context.Background()
-	if err := h(ctx, resp, req, map[string]string{}); err != nil {
-		t.Fatal(err)
-	}
-}

api/server/server.go

@@ -10,15 +10,14 @@ import (
 	"os"
 	"strings"
 
-	"github.com/gorilla/mux"
-
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/docker/docker/api"
-	"github.com/docker/docker/context"
 	"github.com/docker/docker/daemon"
 	"github.com/docker/docker/pkg/sockets"
 	"github.com/docker/docker/utils"
+	"github.com/gorilla/mux"
+	"golang.org/x/net/context"
 )
 
 // Config provides the configuration for the API server

api/server/server_test.go

@@ -5,7 +5,7 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	"github.com/docker/docker/context"
+	"golang.org/x/net/context"
 )
 
 func TestMiddlewares(t *testing.T) {
@@ -19,12 +19,9 @@ func TestMiddlewares(t *testing.T) {
 	ctx := context.Background()
 
 	localHandler := func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-		if ctx.Version() == "" {
+		if versionFromContext(ctx) == "" {
 			t.Fatalf("Expected version, got empty string")
 		}
-		if ctx.RequestID() == "" {
-			t.Fatalf("Expected request-id, got empty string")
-		}
 		return nil
 	}
 

api/server/volume.go

@@ -5,7 +5,7 @@ import (
 	"net/http"
 
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/context"
+	"golang.org/x/net/context"
 )
 
 func (s *Server) getVolumesList(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

context/context.go

@@ -1,64 +0,0 @@
-package context
-
-import (
-	"golang.org/x/net/context"
-
-	"github.com/docker/docker/pkg/version"
-)
-
-const (
-	// RequestID is the unique ID for each http request
-	RequestID = "request-id"
-
-	// APIVersion is the client's requested API version
-	APIVersion = "api-version"
-)
-
-// Context is just our own wrapper for the golang 'Context' - mainly
-// so we can add our over version of the funcs.
-type Context struct {
-	context.Context
-}
-
-// Background creates a new Context based on golang's default one.
-func Background() Context {
-	return Context{context.Background()}
-}
-
-// WithValue will return a Context that has this new key/value pair
-// associated with it. Just uses the golang version but then wraps it.
-func WithValue(ctx Context, key, value interface{}) Context {
-	return Context{context.WithValue(ctx, key, value)}
-}
-
-// RequestID is a utility func to make it easier to get the
-// request ID associated with this Context/request.
-func (ctx Context) RequestID() string {
-	val := ctx.Value(RequestID)
-	if val == nil {
-		return ""
-	}
-
-	id, ok := val.(string)
-	if !ok {
-		// Ideally we shouldn't panic but we also should never get here
-		panic("Context RequestID isn't a string")
-	}
-	return id
-}
-
-// Version is a utility func to make it easier to get the
-// API version string associated with this Context/request.
-func (ctx Context) Version() version.Version {
-	val := ctx.Value(APIVersion)
-	if val == nil {
-		return version.Version("")
-	}
-
-	ver, ok := val.(version.Version)
-	if !ok {
-		// Ideally we shouldn't panic but we also should never get here
-		panic("Context APIVersion isn't a version.Version")
-	}
-	return ver
-}

context/context_test.go

@@ -1,35 +0,0 @@
-package context
-
-import (
-	"testing"
-
-	"github.com/docker/docker/pkg/version"
-)
-
-func TestContext(t *testing.T) {
-	ctx := Background()
-
-	// First make sure getting non-existent values doesn't break
-	if id := ctx.RequestID(); id != "" {
-		t.Fatalf("RequestID() should have been '', was: %q", id)
-	}
-
-	if ver := ctx.Version(); ver != "" {
-		t.Fatalf("Version() should have been '', was: %q", ver)
-	}
-
-	// Test basic set/get
-	ctx = WithValue(ctx, RequestID, "123")
-	if ctx.RequestID() != "123" {
-		t.Fatalf("RequestID() should have been '123'")
-	}
-
-	// Now make sure after a 2nd set we can still get both
-	ctx = WithValue(ctx, APIVersion, version.Version("x.y"))
-	if id := ctx.RequestID(); id != "123" {
-		t.Fatalf("RequestID() should have been '123', was %q", id)
-	}
-	if ver := ctx.Version(); ver != "x.y" {
-		t.Fatalf("Version() should have been 'x.y', was %q", ver)
-	}
-}