Docker File

Sample docker file for node project

FROM node:alpine

WORKDIR '/app'

COPY package.json .

RUN npm install
COPY . .

CMD ["npm","start"]

Sample Compose file

Docker compose file sample

version: '3'

services:
    redis-server:
        image: 'redis'
    node-app:
        build: .
        ports:
            - "4001:8081"

Extract of a node app calling redis

Connection a node server to a redis server within docker

const app = express();
const client = redis.createClient({
    host: 'redis-server',
    port: 6379
});

Using Docker compose

Getting docker compose to build the container

docker-compose up --build

Running Docker containers in background mode

run in back ground mode

docker run -d redus

get running containers

docker ps

stop a running container

docker stop <container id>

Starting and stopping docker-compose

Start compose in backround

docker-compose up -d

check containers running by running docker ps

dcoker ps

Stoping compose

docker-compose down

Mitigating containers failing by using the restart 'always' command

version: '3'

services:
    redis-server:
        restart: always
        image: 'redis'
    node-app:
        restart: always
        build: .
        ports:
            - "4001:8081"

Status code for process exist

0 = we exited and everything is OK
1,2,3 etc = we existed because something went wrong!

Using a pipeline to deploy to production

---development --> testing --> production --|   
|----------------<<<------------------------|   

Generqate empty react app for testing

npm install -g create-react-app
create-react-app frontend

npm usefull comannds

Starts a development server for development purpose only

npm run start

Runs tests associated with the project

npm run test

Builds a production version of the application

npm run build

Development docker file

used only for development dockerfile.dev

FROM node:alpine

WORKDIR '/app'

COPY package.json .

RUN npm install
COPY . .

CMD ["npm","run","start"]

Building the development docker file

docker build -f dockerfile.dev .

Running the container

docker run -p 3000:3000 -v /app/node_modules -v $(pwd):/app <image id>

note:
 -v /app/node_modules 
 this means use the /app/node_modules contained within the container instaead of the app directory
 this is a placeholder for a folder in the container

if you are running on Windows, please read this: Create-React-App has some issues detecting when files get changed on Windows based machines. To fix this, please do the following:

In the root project directory, create a file called .env

Add the following text to the file and save it: CHOKIDAR_USEPOLLING=true

That's all!

For more on why this is required, you can check out: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-start-doesn-t-detect-changes

Doing the same with docker compose

version: '3'
services:
    web:
        build: 
            context: .
            dockerfile: Dockerfile.dev
        ports:
            - "3000:3000"
        volumes:
            - /app/node_modules
            - .:/app

Running the development tests within a container

docker run -it <imnage id> npm run test

Add a test service for testing only

version: '3'
services:
    web:
        build: 
            context: .
            dockerfile: Dockerfile.dev
        ports:
            - "3000:3000"
        volumes:
            - /app/node_modules
            - .:/app
    tests:
        build: 
            context: .
            dockerfile: Dockerfile.dev
        volumes:
            - /app/node_modules
            - .:/app
        command: ["npm", "run", "test"]