Update RestartPolicy of container

Add `--restart` flag for `update` command, so we can change restart
policy for a container no matter it's running or stopped.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>

docs/reference/commandline/update.md

@@ -12,7 +12,7 @@ parent = "smn_cli"
 
     Usage: docker update [OPTIONS] CONTAINER [CONTAINER...]
 
-    Updates container resource limits
+    Update configuration of one or more containers
 
       --help=false               Print usage
       --blkio-weight=0           Block IO (relative weight), between 10 and 1000
@@ -25,11 +25,12 @@ parent = "smn_cli"
       --memory-reservation=""    Memory soft limit
       --memory-swap=""           A positive integer equal to memory plus swap. Specify -1 to enable unlimited swap
       --kernel-memory=""         Kernel memory limit: container must be stopped
+      --restart                  Restart policy to apply when a container exits
 
-The `docker update` command dynamically updates container resources.  Use this
-command to prevent containers from consuming too many resources from their
-Docker host.  With a single command, you can place limits on a single
-container or on many. To specify more than one container, provide
+The `docker update` command dynamically updates container configuration.
+You can use this command to prevent containers from consuming too many resources
+from their Docker host.  With a single command, you can place limits on
+a single container or on many. To specify more than one container, provide
 space-separated list of container names or IDs.
 
 With the exception of the `--kernel-memory` value, you can specify these
@@ -38,6 +39,10 @@ options on a running or a stopped container. You can only update
 stopped container, the next time you restart it, the container uses those
 values.
 
+Another configuration you can change with this command is restart policy,
+new restart policy will take effect instantly after you run `docker update`
+on a container.
+
 ## EXAMPLES
 
 The following sections illustrate ways to use this command.
@@ -59,3 +64,10 @@ To update multiple resource configurations for multiple containers:
 ```bash
 $ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse
 ```
+
+### Update a container's restart policy
+
+To update restart policy for one or more containers:
+```bash
+$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse
+```

man/docker-update.1.md

@@ -2,7 +2,7 @@
 % Docker Community
 % JUNE 2014
 # NAME
-docker-update - Update resource configs of one or more containers
+docker-update - Update configuration of one or more containers
 
 # SYNOPSIS
 **docker update**
@@ -17,15 +17,16 @@ docker-update - Update resource configs of one or more containers
 [**-m**|**--memory**[=*MEMORY*]]
 [**--memory-reservation**[=*MEMORY-RESERVATION*]]
 [**--memory-swap**[=*MEMORY-SWAP*]]
+[**--restart**[=*""*]]
 CONTAINER [CONTAINER...]
 
 # DESCRIPTION
 
-The `docker update` command dynamically updates container resources.  Use this
-command to prevent containers from consuming too many resources from their
-Docker host.  With a single command, you can place limits on a single
-container or on many. To specify more than one container, provide
-space-separated list of container names or IDs.
+The `docker update` command dynamically updates container configuration.
+you can Use this command to prevent containers from consuming too many 
+resources from their Docker host.  With a single command, you can place 
+limits on a single container or on many. To specify more than one container,
+provide space-separated list of container names or IDs.
 
 With the exception of the `--kernel-memory` value, you can specify these
 options on a running or a stopped container. You can only update
@@ -33,6 +34,10 @@ options on a running or a stopped container. You can only update
 stopped container, the next time you restart it, the container uses those
 values.
 
+Another configuration you can change with this command is restart policy,
+new restart policy will take effect instantly after you run `docker update`
+on a container.
+
 # OPTIONS
 **--blkio-weight**=0
    Block IO weight (relative weight) accepts a weight value between 10 and 1000.
@@ -70,6 +75,9 @@ be updated to a stopped container, and affect after it's started.
 **--memory-swap**=""
    Total memory limit (memory + swap)
 
+**--restart**=""
+   Restart policy to apply when a container exits (no, on-failure[:max-retry], always, unless-stopped).
+
 # EXAMPLES
 
 The following sections illustrate ways to use this command.
@@ -91,3 +99,10 @@ To update multiple resource configurations for multiple containers:
 ```bash
 $ docker update --cpu-shares 512 -m 300M abebf7571666 hopeful_morse
 ```
+
+### Update a container's restart policy
+
+To update restart policy for one or more containers:
+```bash
+$ docker update --restart=on-failure:3 abebf7571666 hopeful_morse
+```