Are you trying to build and push a Docker image from GitHub Actions?
Perhaps you’re getting an error like this:
Cannot connect to the Docker daemon at unix:///var/run/docker.sock.
followed by
Is the docker daemon running?
No problem. This means that the Docker client is failing to connect to the Docker daemon. Here are two options to fix that.
The first thing that’s required is to set up a separate Docker-in-Docker service. Once that’s sorted you need to configure the mode of communication with that service. There are two alternatives: socket or port.
Using a Socket
To use a socket to communicate with the Docker-in-Docker service you need to volume mount /var/run/docker.sock.
name: Test Docker on GitHub Actions
on:
pull_request:
push:
branches:
- master
jobs:
push_container:
runs-on: ubuntu-latest
services:
docker:
image: docker:dind
options: --privileged --shm-size=2g
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
container:
image: ubuntu:latest
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Install Docker
run: |
apt-get update
apt-get install -y docker.io
- name: Test Docker
run: |
docker version
docker info
Using a Port
To connect via TCP port 2375 you need to expose that port from the service.
name: Test Docker on GitHub Actions
on:
pull_request:
push:
branches:
- master
jobs:
push_container:
runs-on: ubuntu-latest
services:
docker:
image: docker:dind
options: --privileged
ports:
- 2375:2375
container:
image: ubuntu:latest
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Install Docker
run: |
apt-get update
apt-get install -y docker.io
- name: Test connection
run: |
apt-get update
apt-get install -y iputils-ping
ping -c 3 docker
- name: Test Docker
run: |
docker version
docker info
The step that tests the network connection using ping is not necessary. Nor is the step that tests the connection to the Docker service. Once you have got this running you can safely remove those steps.