Merge pull request #1718 from ijc/dial-stdio-npipe-on-windows

dial-stdio: handle connections which lack CloseRead method.

cli/command/system/cmd.go

@@ -1,8 +1,6 @@
 package system
 
 import (
-	"runtime"
-
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
 	"github.com/spf13/cobra"
@@ -21,12 +19,8 @@ func NewSystemCommand(dockerCli command.Cli) *cobra.Command {
 		NewInfoCommand(dockerCli),
 		newDiskUsageCommand(dockerCli),
 		newPruneCommand(dockerCli),
+		newDialStdioCommand(dockerCli),
 	)
-	if runtime.GOOS != "windows" {
-		cmd.AddCommand(
-			newDialStdioCommand(dockerCli),
-		)
-	}
 
 	return cmd
 }

cli/command/system/dial_stdio.go

@@ -34,10 +34,18 @@ func runDialStdio(dockerCli command.Cli) error {
 	if err != nil {
 		return errors.Wrap(err, "failed to open the raw stream connection")
 	}
-	connHalfCloser, ok := conn.(halfCloser)
-	if !ok {
+	defer conn.Close()
+
+	var connHalfCloser halfCloser
+	switch t := conn.(type) {
+	case halfCloser:
+		connHalfCloser = t
+	case halfReadWriteCloser:
+		connHalfCloser = &nopCloseReader{t}
+	default:
 		return errors.New("the raw stream connection does not implement halfCloser")
 	}
+
 	stdin2conn := make(chan error)
 	conn2stdout := make(chan error)
 	go func() {
@@ -90,6 +98,19 @@ type halfCloser interface {
 	halfWriteCloser
 }
 
+type halfReadWriteCloser interface {
+	io.Reader
+	halfWriteCloser
+}
+
+type nopCloseReader struct {
+	halfReadWriteCloser
+}
+
+func (x *nopCloseReader) CloseRead() error {
+	return nil
+}
+
 type halfReadCloserWrapper struct {
 	io.ReadCloser
 }