Notes.md

Demo 1 - The Basics

Goal: Show basic app running inside docker container w/ Docker & docker-compose

Steps

1. Run basic app.js locally - show that it works on port 3000

   npm install
   node app

   This is where it gets fun. Do you have node.js installed? What about npm? Is the version right? What about your path?

   If you were lucky enough that it worked out of the gate - hurray! If not, don't worry about fixing it. There is a better way.

2. Containerize it!

   Now it is time for us to take our first dive into Docker. You can find install links here.

   docker build -t demo1 .
   docker run -p 3001:3000 demo1

   This will build an image for our app according to what we have layed out in our Dockerfile and tag it as demo1. Then, we run a container based on that image on the host port 3001.

   To stop this container, check out your running docker containers and then kill the one we just started.

   docker ps 
   # CONTAINER ID        IMAGE      ...   
   # ab9463942144        demo1      ...
   
   docker kill ab9463942144

3. Our container copies in all your code at the time of build, so how does this work for local development?

   We could use vanilla docker commands, but docker compose makes things like mounting volumes and setting environment variables so much easier!

   docker-compose run app npm install
   docker-compose up

   Since docker-compose mounts the current directory as a volume, it is actually going to use your local node_modules directory. Running npm install through docker-compose will make sure that any platform specific dependancies (like nodemon) will work correctly.

   You should now see the app up and running on port 3002. And now, if you edit the app.js code, you should see your server automatically restart!