CODEWITHSUNDEEP
node.jsdockerdocker-composedockerfile
Gabb0
Gabb0

Reputation: 264

Docker: Best practice for development and production environment

Suppeose I have a simple node.js app. I can build a container to run the app with a simple Dockerfile like this:

FROM ubuntu:16.04
RUN apt-get update && apt-get install -y nodejs nodejs-legacy npm
COPY . /app
WORKDIR /app
RUN npm install
CMD node index.js

This will copy the source code into the container and I can ship it off to a registry no problem.

But for development I don't want to rebuild the container for every change in my code. So naturally, I use a volume in combination to nodemon. Here's my questions:

So my question is really: How do I keep dev and deploy environments separate. Two Dockerfiles? Two compose-files? Are there any best practices?

Upvotes: 8

Views: 7939

Answers (3)

Shawn C.
Shawn C.

Reputation: 6841

So the way I handle it is I have 2 Docker files (Dockerfile and Dockerfile.dev).

In the Dockerfile.dev I have:

FROM node:6

# Update the repository
RUN apt-get update

# useful tools if need to ssh in or used by other tools
RUN apt-get install -y curl net-tools jq

# app location
ENV ROOT /usr/src/app

COPY package.json /usr/src/app/

# copy over private npm repo access file
ADD .npmrc /usr/src/app/.npmrc

# set working directory
WORKDIR ${ROOT}

# install packages
RUN npm install

# copy all other files over
COPY . ${ROOT}

# start it up
CMD [ "npm", "run", "start" ]

# what port should I have
EXPOSE 3000

My NPM scripts look like this

"scripts": {
    ....
    "start": "node_modules/.bin/supervisor -e js,json --watch './src/' --no-restart-on error ./index.js",
    "start-production": "node index.js",
    ....
},

You will notice it uses supervisor for start so any changes to any file under src will cause it to restart the server without requiring a restart to docker.

Last is the docker compose.

dev:
  build: .
  dockerfile: Dockerfile.dev
  volumes:
    - "./src:/usr/src/app/src"
    - "./node_modules:/usr/src/node_modules"
  ports:
    - "3000:3000"

prod:
  build: .
  dockerfile: Dockerfile
  ports:
    - "3000:3000"

So you see in a dev mode it loads and mounts the current directory's src folder to the container at /usr/src/app/src and also the node_modules directory to the /usr/src/node_modules.

This makes it so that I can make changes locally and save, the volume will update the container's file, then supervisor will see that change and restart the server.

** Note as it doesn't watch the node_modules folder you have to change another file in the src directory to do the restart **

Upvotes: 5

mieciu
mieciu

Reputation: 458

You can use single Dockerfile in which you'll just declare VOLUME section.

Remember that volume won't get mounted unless you'll specify that explicitly during docker run with -v <path>:<path> option. Having that given, you can declare multiple VOLUMEs even in your prod environment.

Upvotes: 1

Piotr Dobrysiak
Piotr Dobrysiak

Reputation: 76

Use environment variables. See the documentation Docker env. This is the recommended way, also for use in the production.

Upvotes: 3

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