docker in production

filename for development

Dockerfile.dev

filename for prod

Dockerfile

Question is how to build docker with a custom file name bcz by default it searches for Dockerfile only

answer: docker build -f Dockerfile.dev

another problem 

anytime we make any change to our code we need to build it again

we need to find someway via which if we make some change in the code, it automatically gets pushed to the container without rebuilding and restarting the container

Solution:

Docker volume

the problem was we taking the snapshot of the project and placing it inside the container

so instead, now we will be creating the reference, that will point to the local machine

eg. docker run -p 3000:3000 -v /app/node_modules -v $(pwd):/app <imageid>

-v /app/node_modules  -> denotes that dont map it to the local machine

-v $(pwd):/app -> say that map present working dir to /app in the docker

writing the same code in docker-compose to simplify

version: '3'

services:

  web:

    build: .

    ports:

      - "3000:3000"

    volumes:

      - /app/node_modules

      - .:/app

this one is with normal build but since our project doesn't contain Dockerfile and instead contains Dockerfile.dev, we need to make some changes

version: '3'

services:

  web:

    build:

      context: . #location of the working directory

      dockerfile: Dockerfile.dev

    ports:

      - "3000:3000"

    volumes:

      - /app/node_modules

      - .:/app

When are using reference then we can remove the " COPY . . " from the docker file bcz we are anyways referencing but anyways that can be used as inspiration to setup production env and its suggested to leave it there

So this was all about the dev env

anytime we want to go to test env, we just need to  change "npm run start" to "npm run test"

FROM node:alpine

WORKDIR '/app'

COPY package.json .

RUN npm install

COPY . .

CMD ["npm","run","test"]

or in the same build image of the dev

we can run it like

docker build -f Dockerfile.dev

return a container id

dev run <container-id>  npm run start

the above command will only give output, if we want to add input too then we need to add -it

dev run <container-id>  npm run start

For having out code in production we will need things like nginx
so to use and set up that bcz nginx will have different image base .
So we will have multi step build process
it will have build phase and run phase

To run nginx with code

FROM node:alpine as builder
# we are tagging the phase so everything under this can be reffered by builder

WORKDIR '/app'
COPY package.json .
RUN npm install
COPY . .
RUN npm run build

#build folder will be created inside of the working directory and that is the folder that we care about /app/build

#run phase for running nginx

FROM nginx
# this also states that previous block is complete
COPY  --from=builder /app/build /usr/share/nginx/html
#using this container will be-default take care of starting up nginx