pelicin › devops › Docker

Setup

This page explains how to install Docker.

Linux

You can follow the instruction on https://docs.docker.com/engine/install/ubuntu/.

1. Install Docker Engine

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin

2. Verify installation

sudo docker run hello-world

Mac

You need to install a virtual machine to run Docker on Mac. (Installing Docker Desktop or Rancher Desktop takes care of this.)

1. Install Docker

brew install --cask docker

2. Install Docker Desktop or Rancher Desktop

You can follow this link to install Docker Desktop (might need a paid subscription). Otherwise, you can choose to install Rancher Desktop (free).

Ensure that you have followed their installation step (i.e. by click-and-dragging their application's icon to your Applications folder).

If you use Rancher Desktop: Open the app, go to Kubernetes Settings, and ensure you choose "dockerd" for the Container Runtime.

3. Verify installation

Try running the following:

sudo docker run hello-world
# Unable to find image 'hello-world:latest' locally
# latest: Pulling from library/hello-world
# 7050e35b49f5: Pull complete
# Digest: sha256:13e367d31ae85359f42d637adf6da428f76d75dc9afeb3c21faea0d976f5c651
# Status: Downloaded newer image for hello-world:latest

# Hello from Docker!
# This message shows that your installation appears to be working correctly.
# ...

If it fails, try the troubleshooting below.

4. Troubleshooting

Ensure that your VM or Rancher Desktop is running. If you use Rancher Desktop, ensure that you have chosen "dockerd" for the Container Runtime.

If you see error like docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?, check your docker context:

docker context ls
# NAME        DESCRIPTION                               DOCKER ENDPOINT               KUBERNETES ENDPOINT                                                                       ORCHESTRATOR
# default *   Current DOCKER_HOST based configuration   unix:///var/run/docker.sock   https://6E4A4AC9E64703A206C54E673154A8C1.sk1.ap-southeast-1.eks.amazonaws.com (default)   swarm

See if the socket file such as /var/run/docker.sock exists:

ls /var/run/docker.sock

If it doesn't check the socket of Rancher Desktop:

which docker
# /Users/ferdinand.antonius/.rd/bin/docker
ls /Users/ferdinand.antonius/.rd
# bin         docker.sock

Create a new docker context and use that new context

docker context create rancher-desktop --docker host=unix:///Users/ferdinand.antonius/.rd/docker.sock\
# Successfully created context "rancher-desktop"
docker context use rancher-desktop
# Current context is now "rancher-desktop"

References