Docker Installation Guide¶

Bookcard relies on Docker. If you don't have it installed:

Windows/Mac: Install Docker Desktop.
Linux: Follow the official installation guide for your distribution.

Ubuntu Installation Example¶

For Ubuntu users, here is a quick reference (see official docs for details):

# 1. Add Docker's official GPG key:
sudo apt update
sudo apt 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:
sudo tee /etc/apt/sources.list.d/docker.sources <<EOF
Types: deb
URIs: https://download.docker.com/linux/ubuntu
Suites: $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}")
Components: stable
Signed-By: /etc/apt/keyrings/docker.asc
EOF

sudo apt update

# 2. Install Docker packages
sudo apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# 3. Verify installation
sudo docker run hello-world

Linux Post-installation Steps¶

These optional post-installation procedures describe how to configure your Linux host machine to work better with Docker.

Manage Docker as a non-root user¶

The Docker daemon binds to a Unix socket, not a TCP port. By default it's the root user that owns the Unix socket, and other users can only access it using sudo. The Docker daemon always runs as the root user.

If you don't want to preface the docker command with sudo, create a Unix group called docker and add users to it.

Warning: The docker group grants root-level privileges to the user. For details on how this impacts security in your system, see Docker Daemon Attack Surface.

To create the docker group and add your user:

Create the docker group.
```
sudo groupadd docker
```
Add your user to the docker group.
```
sudo usermod -aG docker $USER
```
Log out and log back in so that your group membership is re-evaluated. If you're running Linux in a virtual machine, it may be necessary to restart the virtual machine for changes to take effect. You can also run the following command to activate the changes to groups:
```
newgrp docker
```
Verify that you can run docker commands without sudo.
```
docker run hello-world
```
If you initially ran Docker CLI commands using sudo before adding your user to the docker group, you may see a permission error. To fix this, change ownership of the ~/.docker/ directory:
```
sudo chown "$USER":"$USER" /home/"$USER"/.docker -R
sudo chmod g+rwx "$HOME/.docker" -R
```

Configure Docker to start on boot with systemd¶

Many modern Linux distributions use systemd to manage which services start when the system boots. On Debian and Ubuntu, the Docker service starts on boot by default.

To automatically start Docker and containerd on boot for other Linux distributions using systemd, run the following commands:

sudo systemctl enable docker.service
sudo systemctl enable containerd.service

To stop this behavior, use disable instead.

sudo systemctl disable docker.service
sudo systemctl disable containerd.service