Docker

Docker is an open-source platform for building, shipping, and running applications in containers. This image provides a clean Ubuntu 24.04 environment with Docker CE and Docker Compose pre-installed, ready for you to deploy any containerised workload.

Software included

Component	Version
Docker CE	Latest stable
Docker Compose plugin	Latest stable
Ubuntu	24.04 LTS

Getting started

1. Connect to your VM

ssh ubuntu@<your-vm-ip>

2. Verify Docker is running

There is no first-boot configuration. Docker starts immediately after the VM boots.

docker version
docker compose version

The ubuntu user is pre-added to the docker group, so you can run Docker commands without sudo.

3. Run your first container

docker run --rm hello-world

4. Deploy with Docker Compose

Create a docker-compose.yml file and bring up your stack:

docker compose up -d

Managing Docker

# List running containers
docker ps

# View logs for a container
docker logs <container-name> -f

# Stop a container
docker stop <container-name>

# Pull the latest image
docker pull <image-name>

# Check Docker service status
systemctl status docker

# Restart Docker
sudo systemctl restart docker

Docker log files are limited to 10 MB per file with a maximum of 3 rotated files to prevent disk exhaustion.

Security

UFW is not enabled by default in the Docker marketplace image.

The ZCP firewall and port-forwarding rules remain part of exposure control. Before you expose application ports, enable and configure UFW or another host firewall. To use UFW, allow SSH before you enable it:

sudo ufw allow 22/tcp
sudo ufw enable
sudo ufw status

When you publish container ports with -p or ports: in Compose, Docker manages its own iptables rules. These rules can bypass UFW, so do not rely on UFW alone to restrict a published port.

To make a published port available only on the VM, bind it to the loopback interface:

docker run -p 127.0.0.1:80:80 <image>

Or in docker-compose.yml:

ports:
  - '127.0.0.1:80:80'