Setting Container Restart Policy

To configure the restart policy for a container, use the --restart flag when using the docker run command. The value of the --restart flag can be any of the following:

Flag	Description
no	Do not automatically restart the container. (the default)
on-failure[:max-retries]	Restart the container if it exits due to an error, which manifests as a non-zero exit code. Optionally, limit the number of times the Docker daemon attempts to restart the container using the :max-retries option.
always	Always restart the container if it stops. If it is manually stopped, it is restarted only when Docker daemon restarts or the container itself is manually restarted. (See the second bullet listed in restart policy details)
unless-stopped	Similar to always, except that when the container is stopped (manually or otherwise), it is not restarted even after Docker daemon restarts.

The following example starts a Redis container and configures it to always restart unless it is explicitly stopped or Docker is restarted.

docker run -d --restart unless-stopped redis

This command changes the restart policy for an already running container named redis.

docker update --restart unless-stopped redis

And this command will ensure all currently running containers will be restarted unless stopped.

docker update --restart unless-stopped $(docker ps -aq)