Installing Docker on a Raspberry Pi: Quick and Easy

Ever wondered how to save time when installing specific applications on Raspberry Pi?

One solution is to write documentation yourself when installing (and later, when modifying configuration files). I did/do this, however there is another method.

A very big advantage of Docker is that you can manage specific applications as "image files" and then share them with others (or even yourself). Preconfigured apps, save a lot of time, and are sure to run the same way on all devices.

Benefits:
- Easy to manage (install/uninstall in one command, no junk left behind)
- Run anywhere, pre-configured sub-applications
- Can run in any number of instances
- Very simple backup process (Docker registry, e.g. Docker Hub)
- Combined with Kubernetes, scalable performance when using multiple Raspberry Pi

However, there is a disadvantage compared to native deployment:
- It takes up a relatively large amount of ehly to install Docker, about 230MB on the SD card, which can matter when using small cards.

Overall, I think it's very worth using, it's not a coincidence that it's so popular :)

Installation

Instead of installing the Docker with apt install docker, we will use this below command, otherwise it will cause a few issues (e.g. the docker command is not available by default)

curl -sSL https://get.docker.com | sh

The installation process will takes up to a few minutes.

Just make sure that you can use it with "pi" user:

sudo usermod -aG docker pi

Then close the current session, start a new one, and you're ready! No more steps!

Usage of Docker - Basics commands

1. Pulling an Image: Before you can run a container, you need to download an image that contains the necessary files and dependencies. You can do this by using the docker pull command, followed by the name of the image you want to download. For example, to download the official Nginx image, you can run the following command:
   docker pull nginx
   
   

   

   
   
   
2. Running a Container: Once you have downloaded an image, you can use the docker run command to start a container. For example, to start a container based on the Nginx image, you can run the following command:
   docker run -d -p 8080:80 nginx
   
   In this command, -d tells Docker to run the container in the background, -p maps port 8080 on the host to port 80 in the container, and nginx specifies the name of the image to use.
   
   

   

   
   
   
3. Listing Containers: To see a list of running containers, you can use the docker ps command. This will display a list of containers along with their status, ID, and other details.
   
   

   

   
   
   
4. Listing downloaded images: When you run this command, Docker will display a list of images available on your system. Each image is represented by its repository, tag, image ID, and size. To do this, you can use the following command:
   docker images
   
   

   

   
   
   
5. Stopping a Container: To stop a running container, you can use the docker stop command followed by the container ID or name. For example, to stop a container with the ID 062d4ce75d5d, you can run the following command:
   docker stop 062d4ce75d5d
   

   

   
   
   
6. Removing a Container: To remove a stopped container, you can use the docker rm command followed by the container ID or name. For example, to remove a container with the ID 062d4ce75d5d, you can run the following command:
   docker rm 062d4ce75d5d
   
   

   

   
   
   
7. Removing an image: To remove a downloaded image (and free up a disk space), you can use the docker rmi command followed by the image ID or name. For example, to remove an image with the name nginx, you can run the following command:
   docker rmi nginx
   

   

This was a very simple guide to help you get started with containerisation and save yourself a lot of time. I hope you found it useful. If you have any questions, scroll down and ask them in the comment section.