Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

Installing Docker and Docker Swarm

Docker

The reason why we’re using Docker to run our apps is because it provides strong isolation between different runtimes. It’s also very quick to spin up and tear down containers. Furthermore, Docker is widely adopted, so you benefit from a huge ecosystem of images, documentation, and community support. If you have an app in mind that you wanna run, chances are there’s a Docker container for it.

I followed this guide 1 from the official Docker docs to set it up. Be sure to double-check that you’re following the instructions for your distro.

  1. Set up Docker’s apt repository
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$UBUNTU_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update
  1. Install the Docker packages
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
  1. Verify that the Docker installation is successful
 sudo docker run hello-world
  1. Add the current user to the docker group to avoid having to use sudo when executing Docker commands
sudo usermod -aG docker $USER
  1. Restart the machine if still not working.
sudo reboot
  1. Check Docker version (client and server), as well as Docker info
docker version
docker info

Docker Swarm

Docker Swarm helps us overcome the limitations of running plain Docker containers. With it, we can:

  • automate the container lifecycle
  • scale instances up / down
  • replace containers without downtime
  • manage and access secrets
  • run workloads on multiple nodes

In short, Swarm is Docker’s built-in clustering solution. It’s beginner-friendly and easier to get started with than Kubernetes, though less feature-rich.

It isn’t enabled by default, so the first step is to initialize Swarm mode to create a single-node swarm. We also wanna use the --advertise-addr flag to specify an IP address that other nodes can use to join the swarm.

docker swarm init --advertise-addr <ip-address>

  1. Install Docker Engine on Ubuntu ↩