Merge pull request #9082 from SvenDowideit/pr_out_add_some_details_about_the_lifecycle_of_commands_started_with_docker_exec

Add some details about the lifecycle of commands started with docker exec

docs/man/docker-exec.1.md

@@ -15,6 +15,12 @@ docker-exec - Run a command in a running container
 
 Run a process in a running container. 
 
+The command started using `docker exec` will only run while the container's primary
+process (`PID 1`) is running, and will not be restarted if the container is restarted.
+
+If the container is paused, then the `docker exec` command will wait until the
+container is unpaused, and then run.
+
 # Options
 
 **-d**, **--detach**=*true*|*false*

docs/sources/reference/commandline/cli.md

@@ -646,7 +646,11 @@ You'll need two shells for this example.
 
 The `docker exec` command runs a new command in a running container.
 
-The `docker exec` command will typically be used after `docker run` or `docker start`.
+The command started using `docker exec` will only run while the container's primary
+process (`PID 1`) is running, and will not be restarted if the container is restarted.
+
+If the container is paused, then the `docker exec` command will wait until the
+container is unpaused, and then run.
 
 #### Examples