Save learn progress with docker and git

Introduction

Imagine that we start reading a book in office and working along with the examples of the book. Just before leaving the office, we want to save our progress and want to continue from home. How can we do this? Here is a simple example.

Prepare learning environment

I am reading a book about a Javascript library - React. To try the examples of the book, I first clone my learn-node repository from Github.

~$ git clone https://github.com/delrony/learn-node
~$ mv learn-node react

As I am going to learn react, I change the folder name to 'react'.

Now, I need to install Nodejs in my server. Instead of installing Nodejs in my server, I create a Docker image for Nodejs.

~/react$ cd docker
~/react/docker$ docker build -t ronyhuda/learn-react .

Change the name 'ronyhuda' to your docker hub's username.

My working directory is 'react/', where I create the files to follow the examples of the book.

Now I need to run a container for ronyhuda/learn-react image. First, I change the image name in docker-compose.yml file. Then I start the container.

~/react$ docker-compose up -d

I login to the container to prepare my react app:

~/react$ docker exec -it react_learn_1 bash

The first thing I want is to install react.

/var/learner$ yarn add react

This adds two files - package.json and yarn.lock. It also creates a directory, called node_modules. I don't want to add node_modules directory in repository. The .gitignore file already contains the name of the directory.

In the home directory of the container, I create a bare git repositor.

~$ git init --bare react.git

Now, I add this new repository as remote, called 'backup'

/var/learner$ git remote add backup /home/learner/react.git

Also, I add all files to this new repository.

/var/learner$ git add .
/var/learner$ git push -u backup master

All changes are now in local git repository. I don't need the 'origin' anymore. So, I delete that remote.

/var/learner$ git remote rm origin

I finish my learning for today and want to save the progress. I'll save this in docker image and push the image in docker hub.

In Docker container,

/var/learner$ exit

In Host computer,

~/learning/react$ docker stop react_learn_1
~/learning/react$ docker commit react_learn_1 ronyhuda/learn-react:latest
~/learning/react$ docker push ronyhuda/learn-react:latest

Resume learning environment in another computer

I am now in my home and resume my learning. First, I pull the docker image from docker hub.

~/learning $ docker pull ronyhuda/learn-react

Now, I create an empty directory, called react and start a container from the pulled image.

~/learning $ docker run -it -v $PWD/react:/var/learner --name tmp-react ronyhuda/learn-react bash

Checkout code from backup repository and exit the container.

In container

/var/learner$ cd /var
/var$ git clone /home/learner/react.git learner
/var$ exit

Now in host computer, I start the container with docker-compose and log into the container to prepare the learning environment.

~/learning/react $ docker-compose up -d
~/learning/react $ docker exec -it react_learn_1 bash

In the container

/var/learner$ yarn install

And I am now ready to resume learning. I add another react module - react-dom

/var/learner$ yarn add react-dom

Add the changes to local git repository.

/var/learner$ git add .
/var/learner$ git commit -m "Add react-dom"
/var/learner$ git push

Now I am finish with my learning and push the change to the docker hub.

In host computer,

~/learning/react$ docker stop react_learn_1
~/learning/react$ docker commit react_learn_1 ronyhuda/learn-react:latest
~/learning/react$ docker push ronyhuda/learn-react:latest