Merge component 'cli' from git@github.com:docker/cli master

components/cli/cli/command/registry/login.go

@@ -55,22 +55,15 @@ func NewLoginCommand(dockerCli command.Cli) *cobra.Command {
 	return cmd
 }
 
-// unencryptedPrompt prompts the user to find out whether they want to continue
-// with insecure credential storage. If stdin is not a terminal, we assume they
-// want it (sadly), because people may have been scripting insecure logins and
-// we don't want to break them. Maybe they'll see the warning in their logs and
-// fix things.
-func unencryptedPrompt(dockerCli command.Streams, filename string) error {
-	fmt.Fprintln(dockerCli.Err(), fmt.Sprintf(unencryptedWarning, filename))
+// displayUnencryptedWarning warns the user when using an insecure credential storage.
+// After a deprecation period, user will get prompted if stdin and stderr are a terminal.
+// Otherwise, we'll assume they want it (sadly), because people may have been scripting
+// insecure logins and we don't want to break them. Maybe they'll see the warning in their
+// logs and fix things.
+func displayUnencryptedWarning(dockerCli command.Streams, filename string) error {
+	_, err := fmt.Fprintln(dockerCli.Err(), fmt.Sprintf(unencryptedWarning, filename))
 
-	if dockerCli.In().IsTerminal() {
-		if command.PromptForConfirmation(dockerCli.In(), dockerCli.Out(), "") {
-			return nil
-		}
-		return errors.Errorf("User refused unencrypted credentials storage.")
-	}
-
-	return nil
+	return err
 }
 
 type isFileStore interface {
@@ -146,7 +139,7 @@ func runLogin(dockerCli command.Cli, opts loginOptions) error { //nolint: gocycl
 
 	store, isDefault := creds.(isFileStore)
 	if isDefault {
-		err = unencryptedPrompt(dockerCli, store.GetFilename())
+		err = displayUnencryptedWarning(dockerCli, store.GetFilename())
 		if err != nil {
 			return err
 		}

components/cli/docs/reference/commandline/build.md

@@ -425,6 +425,18 @@ Dockerfile are echoed during the build process.
 For detailed information on using `ARG` and `ENV` instructions, see the
 [Dockerfile reference](../builder.md).
 
+You may also use the `--build-arg` flag without a value, in which case the value
+from the local environment will be propagated into the Docker container being
+built:
+
+```bash
+$ export HTTP_PROXY=http://10.20.30.2:1234
+$ docker build --build-arg HTTP_PROXY .
+```
+
+This is similar to how `docker run -e` works. Refer to the [`docker run` documentation](https://docs.docker.com/engine/reference/commandline/run/#set-environment-variables--e---env---env-file)
+for more information.
+
 ### Optional security options (--security-opt)
 
 This flag is only supported on a daemon running on Windows, and only supports
@@ -504,7 +516,7 @@ section in the userguide for more information.
 
 The `--squash` option has a number of known limitations:
 
-- When squashing layers, the resulting image cannot take advantage of layer 
+- When squashing layers, the resulting image cannot take advantage of layer
   sharing with other images, and may use significantly more space. Sharing the
   base image is still supported.
 - When using this option you may see significantly more space used due to
@@ -581,7 +593,7 @@ $ docker build --squash -t test .
 If everything is right, the history will look like this:
 
 ```bash
-$ docker history test 
+$ docker history test
 
 IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
 4e10cb5b4cac        3 seconds ago                                                       12 B                merge sha256:88a7b0112a41826885df0e7072698006ee8f621c6ab99fca7fe9151d7b599702 to sha256:47bcc53f74dc94b1920f0b34f6036096526296767650f223433fe65c35f149eb

components/cli/docs/reference/commandline/load.md

@@ -35,7 +35,7 @@ bzip2, or xz) from a file or STDIN. It restores both images and tags.
 ## Examples
 
 ```bash
-$ docker docker image ls
+$ docker image ls
 
 REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE