First steps:

Step 1: Our application

Make any change in the app source files (e.g src/static/js/app.js)
Rebuild image: docker build -t getting-started .
Run a new container: docker run -dp 3000:3000 getting-started -> will trigger an error because the previous container is using port 3000 already
Get docker id of the current running containers: docker ps
To stop a container: docker stop <container-id>, to remove a container: docker rm <container-id>
To do both: docker rm -f <container-id>
Try to run again the updated image with docker run -dp 3000:3000 getting-started and refresh http://localhost:3000, now it should work

Create a repo on Docker Hub
Name it getting-started, make it public
Login to Docker Hub from terminal: docker login -u YOUR-USER-NAME
To see local docker image from your machine: docker image ls
You need to tag your image with the repo name to be able to push it: docker tag getting-started YOUR-USER-NAME/getting-started
Push: docker push YOUR-USER-NAME/getting-started
You can try the repository on docker playground here, add new instance and type: docker run -dp 3000:3000 YOUR-USER-NAME/getting-started, open port 3000

Demo of unpersisting memory of containers images:

Create a ubuntu container containing a file with a rondom number between 1 to 10K: docker run -d ubuntu bash -c "shuf -i 1-10000 -n 1 -o /data.txt && tail -f /dev/null"
Cat the file: docker exec <container-id> cat /data.txt
Create a new container from the same image, adding the ls command to observe if the file is there: docker run -it ubuntu ls /
Remove persistante container: docker rm -f <container-id>

To create a persistance data with a container:

docker volume create YOUR-VOLUME
Run an image and mount the volume: docker run -dp 3000:3000 -v YOUR-VOLUME:/etc/todos getting-started
Make a change using the app interface at http://localhost:3000
Remove the container and rerun a new one, the change are still visible

To inspect volume: docker volume inspect YOUR-VOLUME

After closing previous containers linked to port 3000, from /app type: docker run -dp 3000:3000 -w /app -v "$(pwd):/app" node:18-alpine sh -c "yarn install && yarn run dev"
%cd% instead of $(pwd) for windows (means current directory from your machine)
Observe logs: docker logs -f <container-id>, of ends by Listening on port 3000, it is ready for change
The app will update automatically from every code change
Once all modifications are done, you can rebuild: docker build -t getting-started .
To repush you need to tag again and push

To create a containers network: docker network create todo-app
To run a MySQL container in the todo-app network: docker run -d --network todo-app --network-alias mysql -v todo-mysql-data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=secret -e MYSQL_DATABASE=todos mysql:8.0
To access the shell of the container: docker exec -it <mysql-container-id> mysql -p
To osbserve the databases: show databases;
Exit: exit
To access ip and containers network infos use nicolaka/netshoot container in your network: docker run -it --network todo-app nicolaka/netshoot
To get MySQL container ip: dig mysql
Exit: exit
To run our app container connected to MySQL container: docker run -dp 3000:3000 -w /app -v "$(pwd):/app" --network todo-app -e MYSQL_HOST=mysql -e MYSQL_USER=root -e MYSQL_PASSWORD=secret -e MYSQL_DB=todos node:18-alpine sh -c "yarn install && yarn run dev"
Check state with: docker logs <container-id>, you should get: [nodemon] starting node src/index.js Connected to mysql db at host mysql Listening on port 3000
Add a task through the app interface at http://localhost:3000
Check MySQL database: docker exec -it <mysql-container-id> mysql -p todos, you should see your tasks saved.