Automate Docker Restarts on Crash or Exit Using a Simple Script

Sometimes, Docker containers fail silently or exit with a non-zero code that isn't caught by standard restart policies. But what happens when a container crashes or exits unexpectedly and --restart=always isn't enough?

In such cases, a custom Docker restart script can act as a watchdog to keep your containers alive and monitored.

Why Use a Restart Script Instead of Docker’s Built-in Policies?

While Docker’s --restart options like always, on-failure, or unless-stopped cover many scenarios, they fall short when:

• The Docker daemon itself crashes or restarts
• You want custom logging or notification when a container dies
• You’re using complex stacks and need to chain actions

That’s where a script comes in handy.

The Script: Restart Docker Containers Automatically

Here's a simple Bash script that monitors and restarts containers by name:

#!/bin/bash

CONTAINER_NAME="my-container"
RESTART_DELAY=5

echo "Monitoring Docker container: $CONTAINER_NAME"

while true
do
    RUNNING=$(docker ps -q -f name="^/${CONTAINER_NAME}$")

    if [ -z "$RUNNING" ]; then
        echo "$(date) - $CONTAINER_NAME not running. Restarting..."
        docker start $CONTAINER_NAME
    else
        echo "$(date) - $CONTAINER_NAME is running."
    fi

    sleep $RESTART_DELAY
done

    

You can use nohup or a service file to start this script. Even you can add in cronjob on @reboot.

So it can start running on reboot. Like:

vim docker-restart-watcher.sh

chmod +x docker-restart-watcher.sh

nohup ./docker-restart-watcher.sh &

​nohup script_name.sh​ 

or ./script_name.sh & 

You can even monitor multiple containers by wrapping the check inside a loop over a list.

 A More Advanced Version

Want to track multiple containers?

#!/bin/bash

CONTAINERS=("web" "worker" "db")
RESTART_DELAY=10 # in seconds

while true
do
  for CONTAINER_NAME in "${CONTAINERS[@]}"
  do
    RUNNING=$(docker ps -q -f name="^/${CONTAINER_NAME}$")

    if [ -z "$RUNNING" ]; then
        echo "$(date) - $CONTAINER_NAME stopped. Restarting..."
        docker start $CONTAINER_NAME
    else
        echo "$(date) - $CONTAINER_NAME is running."
    fi
  done

  sleep $RESTART_DELAY
done

   

This is how you can restart your docker containers, even if it fails and you are not around.

Hope you find it helpful!!