Install Docker Engine

Set up the repository

Update the apt package index:

sudo apt-get update

Install packages to allow apt to use a repository over HTTPS:

sudo apt-get install \
      apt-transport-https \
      ca-certificates \
      curl \
      gnupg-agent \
      software-properties-common

Add Docker’s official GPG key:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Use the following command to set up the stable repository.

sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"

Install Docker Engine - Community

Update the apt package index.

sudo apt-get update

Install the latest version of Docker Engine - Community and containerd, or go to the next step to install a specific version:

sudo apt-get install docker-ce docker-ce-cli containerd.io

Verify that Docker Engine - Community is installed correctly by running the hello-world image.

sudo docker run hello-world

Upgrade Docker Engine - Community

To upgrade Docker Engine - Community, first run sudo apt-get update, then follow the installation instructions, choosing the new version you want to install.

Post-installation steps for Linux

Starting the docker service

Before we can use docker, we need to enable Docker daemon. We can easily do it using systemctl start.

sudo systemctl start docker.service

Manage Docker as a non-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.

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.
On Linux, 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

This command downloads a test image and runs it in a container. When the container runs, it prints an informational message and exits.

Configure Docker to start on boot

Most current Linux distributions (RHEL, CentOS, Fedora, Ubuntu 16.04 and higher) use systemd to manage which services start when the system boots. Ubuntu 14.10 and below use upstart.

For systemd run:

sudo systemctl enable docker

To disable this behavior, use disable instead.

sudo systemctl disable docker

Install Compose

Run this command to download the current stable release of Docker Compose:

sudo curl -L "https://github.com/docker/compose/releases/download/1.24.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

Apply executable permissions to the binary:

sudo chmod +x /usr/local/bin/docker-compose

Test the installation.

docker-compose --version

Running Jekyll locally with Docker

The rest of this post assumes you have Docker and Docker Compose installed and have some basic knowledge of working with it. Docker has some great getting started guides for to Develop with Docker.

The easiest way to get started is probably to use Jekyll with a Gemfile.

Setup a Basic Jekyll site

We’ll start with a basic Jekyll site consisting of three files:

├── _config.yml
├── Gemfile
└── index.md

Create Gemfile in the root with the following:

source 'https://rubygems.org'

gem 'jekyll'

gem 'fortyone-jekyll-theme'

Then the _config.yml with the contents:

name: My Jekyll Website
theme: fortyone-jekyll-theme

And the index.md:

---
title: My page
layout: home
---

# 101.docker

Content is written in [Markdown](https://learnxinyminutes.com/docs/markdown/). Plain text format allows you to focus on your **content**.

Dockerize the site

To use the Jekyll image without having to pass in the required options every time to create a container, we can make use of Docker Compose. Create a file called docker-compose.yml with these contents:

jekyll:
    image: jekyll/jekyll
    command: jekyll serve --watch --incremental
    ports:
        - 4000:4000
    volumes:
        - .:/srv/jekyll

Start the docker jekyll

That’s all! You can start your Jekyll site by browsing to your site’s directory using a terminal and doing

docker-compose up

And go to http://0.0.0.0:4000!

Source code

You can find it here: https://gitlab.com/agustibr/try-docker-jekyll

Deep Dive

Cheatsheet

# find container id running on the desired port from the following output
docker container ls

# stop the container running on the desired port
docker stop <container-id>

# At some point you need to cleanup you local machine and free space. Removes all! Images, Volumes, Containers:
docker system prune -a

via: