Docker actually has built-in functionality for container auto-start through restart policies. When creating or running a container, you can specify one of these policies:

docker run -d --restart unless-stopped my_container_image

Available restart policies:

• no: Do not automatically restart (default)
• on-failure: Restart if exits with non-zero status
• always: Always restart
• unless-stopped: Always restart unless explicitly stopped

For more control, creating systemd service files is recommended:

# /etc/systemd/system/mycontainer.service
[Unit]
Description=My Docker Container
Requires=docker.service
After=docker.service

[Service]
Restart=always
ExecStart=/usr/bin/docker start -a my_container
ExecStop=/usr/bin/docker stop -t 2 my_container

[Install]
WantedBy=multi-user.target

Then enable it:

sudo systemctl enable mycontainer.service

When using Docker Compose, specify restart policies in your docker-compose.yml:

version: '3'
services:
  webapp:
    image: nginx:latest
    restart: unless-stopped
    ports:
      - "80:80"

While supervisord works, it adds unnecessary complexity for Docker containers because:

• Docker already has process supervision built-in
• It creates an additional layer of process management
• Can interfere with Docker's own restart policies
• Makes debugging more complicated

After setting up, test by rebooting and checking:

sudo reboot
# After system comes back up
docker ps -a

Or for systemd services:

systemctl status mycontainer.service

---

Docker provides built-in functionality for container auto-start through its restart policies. This is the most straightforward method and should be your first consideration.

docker run -d --restart unless-stopped your_image

Available restart policies include:

• no: Don't restart (default)
• on-failure: Restart only if container exits with non-zero status
• always: Always restart
• unless-stopped: Similar to always, but respects manual stops

For Ubuntu 14.04 (which uses upstart), we can create a systemd service file that manages our container:

[Unit]
Description=My Container
Requires=docker.service
After=docker.service

[Service]
Restart=always
ExecStart=/usr/bin/docker start -a my_container
ExecStop=/usr/bin/docker stop -t 2 my_container

[Install]
WantedBy=multi-user.target

Then enable it with:

sudo systemctl enable my-container.service

If you're using Docker Compose, you can specify restart policies in your docker-compose.yml:

version: '3'
services:
  webapp:
    image: your_image
    restart: unless-stopped
    ports:
      - "80:80"

Since Ubuntu 14.04 uses upstart by default, you can create an upstart job:

description "Start my_container"
start on filesystem and started docker
stop on runlevel [!2345]
respawn
script
  /usr/bin/docker start -a my_container
end script

Save this as /etc/init/my_container.conf and start it with:

sudo start my_container

After implementing any of these methods, test your setup:

sudo reboot
# After system comes back up
docker ps

This should show your container running if everything was configured correctly.

• For production systems, unless-stopped is generally preferred over always
• Be mindful of container dependencies (database containers should start before app containers)
• Consider using health checks in your containers for more robust auto-restart behavior
• For complex setups, consider using orchestration tools like Kubernetes or Docker Swarm