Yarn packages out of date when running Rails app in Docker - ruby-on-rails

Question

I start my Rails 6 app as Docker containers, but when it starts the Rails server, it keeps giving the error:
warning Integrity check: System parameters don't match
website_1 | error Integrity check failed
website_1 | error Found 1 errors.
website_1 |
website_1 |
website_1 | ========================================
website_1 | Your Yarn packages are out of date!
website_1 | Please run `yarn install --check-files` to update.
website_1 | ========================================
website_1 |
website_1 |
website_1 | To disable this check, please change `check_yarn_integrity`
website_1 | to `false` in your webpacker config file (config/webpacker.yml).
So why is this not working? I have that command in the Dockerfile and also that check is disabled in webpacker.yml.
I build it with docker-compose up --build and then it doesn't seem to give errors.
When I start it with docker-compose up, it will return the erorr when the Rails server is started. Here are the relevant files:
Dockerfile:
FROM ruby:2.6.5-slim
LABEL maintainer="John van Arkelen <johnvanarkelen#fastmail.com>"
RUN apt-get update -qq && apt-get install -y curl build-essential libpq-dev postgresql postgresql-contrib
RUN mkdir /app
RUN mkdir -p /usr/local/nvm
WORKDIR /app
RUN curl -sL https://deb.nodesource.com/setup_11.x | bash -
RUN apt-get install -y nodejs
RUN node -v
RUN npm -v
ENV BUNDLE_PATH /gems
RUN gem install bundler -v 2.0.2
COPY Gemfile Gemfile.lock package.json yarn.lock ./
RUN bundle install
RUN npm install -g yarn
COPY . /app
RUN yarn install --check-files
webpacker.yml:
default: &default
source_path: app/javascript
source_entry_path: packs
public_root_path: public
public_output_path: packs
cache_path: tmp/cache/webpacker
check_yarn_integrity: false
webpack_compile_output: false
docker-compose.yml:
version: '2'
services:
postgres:
image: 'postgres:10.3-alpine'
volumes:
- 'postgres:/var/lib/postgresql/data'
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: password123
POSTGRES_DB: qd_development
env_file:
- '.env'
redis:
image: 'redis:4.0-alpine'
command: redis-server --requirepass password123
volumes:
- 'redis:/data'
website:
depends_on:
- 'postgres'
- 'redis'
build: .
command: bundle exec rails s -p 3000 -b '0.0.0.0'
ports:
- '3000:3000'
volumes:
- '.:/app'
- gem_cache:/gems
environment:
DATABASE_HOST: postgres
POSTGRES_USER: postgres
POSTGRES_PASSWORD: password123
POSTGRES_DB: qd_development
env_file:
- '.env'
volumes:
redis:
postgres:
gem_cache:

Answer 1

It seems to me like you are building your app correctly in the image in the /app directory. But afterward in your docker-compose you mount a local volume over your built /app directory, thereby losing your built /app folder contents.
Try removing the mounted volume '.:/app'.

Answer 2

In your docker-compose.yml, you can also do this to avoid rebuilding everytime time. Then, you can just do docker-compose up
command: bash -c "bundle install && yarn install --check-files && bundle exec rails s -p 3000 -b '0.0.0.0'"