How do I make a Docker container start automatically on system boot?

Question

Yes, docker has restart policies such as docker run --restart=always that will handle this. This is also available in the compose.yml config file as restart: always.

If you want the container to be started even if no user has performed a login (like the VirtualBox VM that I only start and don't want to login each time). Here are the steps I performed to for Ubuntu 16.04 LTS. As an example, I installed a oracle db container:

$ docker pull alexeiled/docker-oracle-xe-11g
$ docker run -d --name=MYPROJECT_oracle_db --shm-size=2g -p 1521:1521 -p 8080:8080 alexeiled/docker-oracle-xe-11g
$ vim /etc/systemd/system/docker-MYPROJECT-oracle_db.service

and add the following content:

[Unit]
Description=Redis container
Requires=docker.service
After=docker.service

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

[Install]
WantedBy=default.target

and enable the service at startup

sudo systemctl enable docker-MYPROJECT-oracle_db.service

For more informations https://docs.docker.com/engine/admin/host_integration/

The default restart policy is no.

For the created containers use docker update to update restart policy.

docker update --restart=always 0576df221c0b

0576df221c0b is the container id.

You can use docker update --restart=on-failure <container ID or name>.

On top of what the name suggests, on-failure will not only restart the container on failure, but also at system boot.

Per the documentation, there are multiple restart options:

Flag            Description
no              Do not automatically restart the container. (the default)
on-failure      Restart the container if it exits due to an error, which manifests as a non-zero exit code.
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.

1) First of all, you must enable docker service on boot

$ sudo systemctl enable docker

2) Then if you have docker-compose .yml file add restart: always or if you have docker container add restart=always like this:

docker run --restart=always and run docker container

Make sure

If you manually stop a container, its restart policy is ignored until the Docker daemon restarts or the container is manually restarted.

see this restart policy on Docker official page

3) If you want start docker-compose, all of the services run when you reboot your system So you run below command only once

$ docker-compose up -d

More "gentle" mode from the documentation:

docker run -dit --restart unless-stopped <image_name>

To start a container and set it to restart automatically on system reboot use

docker run -d --restart unless-stopped ecstatic_ritchie

Where ecstatic_ritchie is an example name specifying the container in interest. Use docker ps -a to list all container names.

To make particular running containers start automatically on system reboot

docker update --restart unless-stopped ecstatic_ritchie

To make all running containers start automatically on system reboot

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

See more on Docker homepage