Docker container doesn't reload Angular app

Question

I have some issue with ng serve in my docker container running by docker-compose.

Dockerfile

FROM node:7.1

RUN mkdir -p /u         


        

Answer 1

A solution can be the chokidar wrapper, which is a dependency of the angular package. I dont know, if that was the status in 2017. You don't need to expose any extra ports. Just use an environment variable in your docker-compose.

Basic configuration:

Dockerfile

CMD ng serve --host 0.0.0.0

docker-compose.yml

environment:
  - CHOKIDAR_USEPOLLING=true

This should hot-reloading your browser. Tested on Chrome and Angular 8

Package for further investigation: https://github.com/paulmillr/chokidar

Answer 2

Webpack uses a port to do live reload of the application. That port is 49153 by default.

You have to expose and bind that port in the container to the host port and that should solve your problem.

So, add this to your Dockerfile.

FROM node:7.1

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY package.json /usr/src/app
RUN npm install
RUN npm install -g angular-cli
COPY . /usr/src/app

EXPOSE 4200 49153

CMD [ "npm", "start" ]'

And this to your docker-compose.yml.

web:
    build: .
    ports:
        - '8089:4200'
        - '49153:49153'
    volumes:
        - .:/usr/src/app/
    environment:
        - NODE_ENV=dev
    command: bash -c "npm start"

Answer 3

Another solution without polling.

Background:

I work on large Angular and React projects, the polling even every 10 seconds (--poll 10000) produce a lot of network traffic (in task manager you can check performance of docker nat interface). And in turn it produces high CPU load.

Solution:

If you use phpStorm/other Intellij produce or VS code you can add File watchers. I wrote the following script that helps me with this:

#!/bin/bash

image="${*:1:1}"
file="${*:2}"
machine=$(docker ps --filter ancestor="$image" --format "{{.ID}}")

if [ -n "$machine" ]
  then
    docker exec "$machine" touch "$file"
fi

After that I added following File Watcher (notice that the Trigger is switched off on external events):

Notes: It is important that your docker exec has no parameter -it as tty or interactive parameters requires to use winpty (located where git bash is installed). Also this solution is not Angular specific it is more docker specific, works the same for any webpack-dev-server app.

Also, phpStorm periodically shows File Cache Conflict dialog about file difference. To disable this prompt one can switched off file sync. https://stackoverflow.com/a/6628645

Answer 4

I found solution for both problems:

1. inotify -> just edit package.json in "scripts" section this line: "start": "ng serve --host 0.0.0.0 --poll", required only for Windows host,

2. hot reload -> add expose 49153 in Dockerfile and ports - '49153:49153' in docker-compose.yml like @kstromeiraos mentioned.

Answer 5

My solution using node:slim.

No need for copying data into containers. Just use volumes.

Dockerfile:

NOTE: --poll 1

FROM node:slim

RUN npm install @angular/cli@latest -g

RUN mkdir -p /home/boilerplate

WORKDIR /home/boilerplate

EXPOSE 4200

CMD ng serve --port 4200 --host 0.0.0.0 --poll 1

Compose:

  project:
    image: project
    build:
      context: .
      dockerfile: projectdir/Dockerfile
    volumes:
    - ./projectdir:/home/boilerplate
    ports:
    - 4200:4200