Install Docker on Alpine

Step 1: Check Docker Service Status

Ensure that the Docker service is running.

sudo service docker status

If Docker is not running, start it:

sudo service docker start

Step 2: Check Docker Daemon Logs

If Docker cannot start, check the logs for more information.

sudo tail -n 50 /var/log/docker.log

Step 3: Verify User Permissions

Make sure your user is in the docker group. This avoids needing to use sudo with every Docker command.

sudo addgroup $(whoami) docker

Then log out and log back in, or reboot the system to apply the group change.

Step 4: Reboot the System

Sometimes, simply rebooting the system can resolve the issue, ensuring that the Docker service and user permissions are applied.

sudo reboot

Step 5: Manually Check Docker Socket Permissions

Ensure that the Docker socket has the correct permissions.

ls -l /var/run/docker.sock

The output should look similar to this:

srw-rw---- 1 root docker 0 Jan  1 12:34 /var/run/docker.sock

If the socket permissions are incorrect, you can manually set them:

sudo chown root:docker /var/run/docker.sock
sudo chmod 660 /var/run/docker.sock

Verify the Fix

After completing the above steps, try running a Docker command again to verify if the issue is resolved:

docker version

Complete Example Script

Here is a script that incorporates the above steps:

#!/bin/sh

# Update the system
sudo apk update
sudo apk upgrade

# Install Docker
sudo apk add docker

# Start and enable the Docker service
sudo service docker start
sudo rc-update add docker boot

# Add the current user to the docker group
sudo addgroup $(whoami) docker

# Reboot the system to apply changes
sudo reboot

Save the script above as install_docker.sh and run it:

sh install_docker.sh

After completing these steps, you should be able to successfully run Docker commands.