Docker 101
This repo will hopfully provide all the resources for someone with little/no docker experience to learn docker
There plenty of great educators out on the magical site of YouTube, some far better than I. Take a moment to watch the following videos before proceeding any further
What is docker? A video that introduces you to docker, some basic command syntax, as well as how to install it on Linux or Mac.
Using windows? No worries!
First make sure to enable and install WSL2...
Then follow this guide to installing Docker desktop with WSL2 backend!
In some cases it may not be possible to use Docker Desktop to manage docker containers. If you are on Mac or Windows, you will need to use an alternative software to create the Docker VM (the VM that brings up all the docker containers under the hood.) Here are some alternatives to Docker Desktop and which platforms are supported.
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- Platforms Supported: Mac
- Notes: Very good solution for Macs, please note there are some special caveats for mounting internal folders that will be discussed below.
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- Platforms Supported: Mac, Windows, Linux
- Notes: Windows requires some special installation steps here
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Linux VM
- Platforms Supported: Mac, Windows
- Notes: If the 2 above solutions aren't possible, you can always create a linux vm using vmware or other such vm solution, and then install docker on the virtual machine following the specific install instructions for that distro, here are the install instructions for Ubuntu, a very user friendly and widely supported linux distro.
Note about mounting directories from host with Colima:
After Colima has been installed successfully, you need to run colima start in order to bring up the Colima VM, which in turn is the VM that handles creating and destroying docker containers. Out of the box colima will mount your entire home directory as a read only volume within the colima VM which makes it easily accessible to Docker. If at any time you wish to mount other directories from your local machine into a container as a volume, you will need to start the colima VM with some additional flags. In the example below, the colima VM is started and will mount a directory on the host found at ~/project to /project within the Colima vm, which in turn makes it accessible to any docker container at the same path /projects as well. This becomes important when we get to Exercise 5 found in this course.
colima start --mount $HOME/project:/project:w
So now that you're familiarized with some basic docker commands, it's time to play around with some exercises. The majority of the exercises in this repo will be in separate folders however the introductory exercise can be done right here from the README
- Exercise 1 (see below!)
- Exercise 2: Disecting Dockerfiles
- Exercise 3: Examining Entrypoints
- Exercise 4: Networking
- Exercise 5: Advanced Entrypoints, File Configs
Note: Not all of the exercises will have a task to complete with a click to reveal answer section
- Pull the latest Ubuntu image
Click to reveal command
docker pull ubuntu:latest
- Using that image, create a container and drop into a bash shell prompt
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docker run -it ubuntu bash
- Exit that shell (
exit- everyone gets a free command) and now daemonize a docker ubuntu container. You don't have to run a command with it if you dont want. Give it a name to make the next step easier.
Click to reveal command
docker run -it -d --name container_name ubuntu
- Find the daemonized container, then connect to it and have it echo the current user
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This is a 2 part process
Find the container:
docker ps
Connect to it and echo the user:
docker exec -it container_name whoami
- Find the Container's IP
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docker inspect container_name | grep -i ipaddress
Bonus if you used grep 😄
- Attach to the daemonized container
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docker attach container_name
- Create a new container, mount this repo inside it, call that directory Learn_Docker. (Hint: do this from a
docker runcommand, end the command with bash so that when the container is brought up you end up in a shell and can verify the dir is there. Stuck? If you are on Linux or Mac mount$(pwd)inside the container. If you're on Windows (or just still stuck) checkout this guide)
Click to reveal command
Alright I'll admit this might be a tough one
On Mac or Linux run the following
docker run -it -v $(pwd):/Learn_docker ubuntu bash
The idea here is that $(pwd) is the absolute path to the current working directory, held in a temporary variable
On windows (ugh)
docker run -it -v //c/path/to/this/folder:/Learn_docker ubuntu bash
What the heck? Well, you need to convert your windows file path to linux-y file path, and the way of doing that is starting the path with double slashes // then the c drive or whatever drive you have. Honestly, run $(pwd) in gitbash from this folder then just add an extra /.
- Cleanup!
List all your containers you created in the process of this exercise and remove them
Click to reveal command
docker ps -a
docker rm containerid
This concludes exercise 1! Please use the folders for the rest of the exercises!