Serving an NX monorepo of angular apps in Docker-compose

Question

I have an NX monorepo with 2 apps:

• Shop
• Landing

I wish to use docker-compose to run my entire environment with eventually some APIs and a database etc etc.

I created a docker-file that takes arguments and could be re-used to to run multiple angular apps in Nx:

# base image
FROM node

ARG APP


# # install chrome for protractor tests
# RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
# RUN sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
# RUN apt-get update && apt-get install -yq google-chrome-stable
# set working directory
WORKDIR /app

# add `/app/node_modules/.bin` to $PATH
ENV PATH /app/node_modules/.bin:$PATH

# install and cache app dependencies
COPY package.json /app/package.json
COPY decorate-angular-cli.js /app/decorate-angular-cli.js
RUN npm install
RUN npm install -g @angular/cli@latest
RUN npm install reflect-metadata tslib rxjs @nestjs/platform-express

# add app
COPY . /app
# start app
CMD npm start $APP -- --host 0.0.0.0 --port 4200 --disableHostCheck=true --poll 100

and I created a docker-compose file that sets up an .net 5 API and the 2 web applications:

version: '3.4'

services:
  sletsgo.user.api:
    image: ${DOCKER_REGISTRY-}sletsgo.user.api
    build:
      context: .
      dockerfile: SletsGo.User.Api/Dockerfile
    ports:
      - "5000:2000"
      - "444:443"

  sletsgo.shop:
    container_name: 'SletsGo.Shop'
    image: ${DOCKER_REGISTRY}sletsgo.shop:dev
    build:
        context: SletsGo
        dockerfile: .docker/Dockerfile
        args:
            - APP=shop
    ports:
        - '4000:4200'
    #volumes:
    #    - sletsgo-web:/app
    #    - '/app/node_modules'

  sletsgo.landing:
    container_name: 'SletsGo.Landing'
    image: ${DOCKER_REGISTRY}sletsgo.landing:dev
    build:
        context: SletsGo
        dockerfile: .docker/Dockerfile
        args:
            - APP=landing
    ports:
        - '4100:4200'
  #  volumes:
  #      - sletsgo-web:/app
  #      - '/app/node_modules'

 


#volumes:
# sletsgo-web:
#    driver: local
#    driver_opts:
#      type: local
#      device: ./SletsGo
#      o: bind

Please note that a lot of lines are commented out. The issue is that if I run this docker-compose i get 2 instances of the shop application ran.

How can i fix this?

P.S. I also imagine that using volumes i might be able to simplify things a lot. But the mounting i tried failed because im using linux containers on a windows machine. If someone is willing to help me to that next level i would like that very much, but for now i just want to run both the web applications.

Answer 1

TL;DR

ARG's are build time variables. You can persist the ARG's value in the images environment during the build or override the services[*].command in the docker-compose.yaml.

---

Persist in the environment

You can persist an environment variable set from a --build-arg in the images environment during the build:

FROM alpine:3
ARG APP
ENV APP=${APP}
CMD echo $APP

Build the docker image: docker build --rm --build-arg APP=123 -t so:66935830 .

Run the docker container: docker run --rm -it so:66935830

Override the command

You can override the command for each service in the docker-compose.yaml:

version: '3.7'
services:
  a:
    image: 'a'
    build:
      context: '.'
    command: ['echo', '123']
  b:
    image: 'b'
    build:
      context: '.'
    command: ['echo', '456']