Getting started
Docker CE vs Docker Desktop
Very important to know that Docker CE often referred to as Docker Engine is not the same as Docker Desktop. Docker Desktop adds new features for development purposes, but it runs a virtual machine (yes, even on Linux) so you will lose some features that you would be able to use with Docker CE.
This tutorial will mostly use Docker CE, but you can use Docker Desktop depending on your needs, however, some of the examples might not work. Whenever an example requires Docker Desktop, it will be noted before the example.
Requirements
Install Docker
Docker can be installed from multiple sources. Not all sources are officially supported by Docker Inc. It is recommended to follow the official way whenever it is possible. Docker is not supported on all Linux distributions, although some distributions have their own way to install Docker or Docker Desktop. Keep in mind that in those cases it is likely that the developers of Docker or people on the Docker forum can’t help you and you need to rely on the community of the distribution you have chosen.
- Docker CE
Docker Community Edition. It is free to use even for commercial projects, although it does not have commercial support. Docker CE is open source an the source code of the daemon is available on GitHub in moby/moby The source code of the client is in docker/cli Installation instructions for Linux containers in the official documentation: engine/install/#server For Windows containers you can follow the instructions of Microsoft: Get Started: Prep Windows for Containers This is the recommended way to run containers natively on the preferred operating system.
- Docker EE
Docker Enterprise Edition doesn’t exist anymore. It was the enterprise version of Docker with commercial support until Mirantis bought Docker EE. See below.
- Mirantis Container Runtime
Mirantis Container Runtime used for Mirantis Kubernetes Engine If you need commercial support (from Mirantis) this is the recommended way.
- Docker Desktop
Docker Desktop was created for two purposes:
It provides developer tools using a virtualized environment based on LinuxKit.
Running native Linux containers is not possible on Windows or macOS, only on Linux. Since Docker Desktop runs Docker CE in a virtual machine Docker Inc can support running Docker containers on macOS and Windows. Docker Inc is doing their best to make you feel you are running native Docker containers, but you need to keep in mind that you are not.
Docker Desktop is not open source, even though LinuxKit is. You can use it on your computer for personal purposes, and it is free for small companies too. Check the official documentation for up-to-date information about whether it is free for you or not. Docker Desktop. At the time of writing this tutorial the short version of Docker Desktop terms is the following:
“Commercial use of Docker Desktop in larger enterprises (more than 250 employees OR more than $10 million USD in annual revenue) requires a paid subscription.”
- Rancher Desktop
Rancher Desktop is similar to Docker Desktop, although it is created for running specific version of Kubernetes. You can use it for running Docker containers, but you will not be able to use the developer tools of Docker Desktop. For the installation instructions, follow the official documentation: Rancher Desktop If you want to know more about using Rancher Desktop with Docker Desktop on the same macOS machine, you can watch my Youtube video: Docker Desktop and Rancher Desktop on the same macOS machine
Install Docker Compose v2
Docker Compose v2 is Docker CLI plugin to run Docker Compose projects. This is the recommended way to use Docker Compose. Since Docker Compose could already be on your system after installing Docker, check the below command first:
docker compose version
Use space between “docker” and “compose”. If the “compose” subcommand doesn’t work, follow the official documentation for the installation instructions: Install Docker Compose
jq for parsing json files
Some of the examples will use jq. Click the link for the installation instruction.
Operating system
Linux is always supported and I do my best to support Docker Desktop on macOS, but not all the examples will work on macOS unless you run Linux in a virtual machine.
Clone the git repository
git clone https://github.com/itsziget/learn-docker.git
Scripts
- system/usr/local/bin/nip.sh
nip.io generates domain names for the public DNS server based on the current WAN or LAN IP address of the host machine. It must be copied into /usr/local/bin/ with the filename “nip.sh”. When you execute “nip.sh”, a domain name will be shown (Ex.: 192.168.1.2.nip.io) which you can use for the examples. The command takes one optional parameter as a subdomain. Ex.: “nip.sh web1”. The result would be: web1.192.168.1.2.nip.io
- system/etc/profile.d/nip.variable.sh
It uses the nip command to set the NIP environment variable so you can use the variable in a docker-compose.yml too.
Make sure you each script is executable before you continue. However, the above scripts are optional and you may not need them in a local virtual machine. If you don’t want to rely on automatic IP address detection, set the NIP variable manually.
Example projects
Example projects are in the learn-docker/projects folder, so go to there.
Check the existence of $NIP variable since you will need it for some examples:
If it does not exist or empty, then set the value manually or run the script below:
All off the examples were tested with Docker 20.10.23. The version of Docker Compose was 2.15.1. You can try with more recent versions but some behaviour could be different in the future.