"npm run build" in Dockerfile: dist folder is generated but disappears - docker

Question

I have a Dockerfile for a Django and Vue.js app that I use along with Gitlab.
The problem that I'm about to describe only happens when deploying via Gitlab CI and the corresponding .gitlab-ci.yml file. When running the docker-compose up command in my local machine, this doesn happen.
So I run docker-compose up and all the instructions in the Dockerfile run apparently fine. But when I check the production server, the dist folder (where the bundle.js and bundle.css should be stored) doesn't exist.
The logs that are spit out while running the Dockerfile confirm that the npm install and npm run build commands are run, and it even confirms that the dist/bundle.js and dist/bundle.css files have been generated. But for some reason they seem to be deleted.
This is my Dockerfile:
FROM python:3.7-alpine
MAINTAINER My Name
ENV PYTHONUNBUFFERED 1
RUN mkdir /app
# make the 'app' folder the current working directory
WORKDIR /app
# copy project files and folders to the current working directory (i.e. 'app' folder)
COPY ./app .
COPY ./requirements.txt /requirements.txt
RUN apk add --update --no-cache postgresql-client
RUN apk add --update --no-cache --virtual .tmp-build-deps \
gcc libc-dev linux-headers postgresql-dev
RUN pip install -r /requirements.txt
RUN apk del .tmp-build-deps
# copy both 'package.json' and 'package-lock.json' (if available)
COPY app/frontend/package*.json ./frontend/
# Install npm
RUN apk add --update nodejs && apk add --update nodejs-npm
# install project dependencies
WORKDIR /app/frontend
RUN npm install
# build app for production with minification
RUN npm run build
RUN adduser -D user
USER user
CMD ["sh ../scripts/entrypoint.sh"]
This is the .gitlab-ci.yml file:
image: docker:latest
services:
- docker:dind
before_script:
- echo "Runnig before_script"
- sudo apt-get install -y python-pip
- sudo apt-get install -y nodejs
- pip install docker-compose
stages:
- test
- build
- deploy
test:
stage: test
script:
- echo "Testing the app"
- docker-compose run app sh -c "python /app/manage.py test && flake8"
build:
stage: build
only:
- develop
- production
- feature/gitlab_ci
script:
- echo "Building the app"
- docker-compose build
deploy:
stage: deploy
only:
- master
- develop
- feature/gitlab_ci
script:
- echo "Deploying the app"
- docker-compose up --build -d
This is the content of the docker-compose.yml file:
version: "3"
services:
app:
build:
context: .
ports:
- "8000:8000"
volumes:
- ./app:/app
command: >
sh -c "python /app/manage.py runserver 0.0.0.0:8000"
environment:
- DB_HOST=db
- DB_NAME=app
- DB_USER=postgres
- DB_PASS=postgres
depends_on:
- db
db:
image: postgres:10-alpine
environment:
- POSTGRES_DB=app
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=postgres
This is the content of the entrypoint.sh file:
#!/bin/bash
(cd .. && ./manage.py collectstatic --noinput)
# Migration files are commited to git. Makemigrations is not needed.
# ./manage.py makemigrations app_name
(cd .. && ./manage.py migrate)
I would like to know why the dist/ folder disappears and how to keep it.

Answer 1

When your docker-compose.yml file says
volumes:
- ./app:/app
that hides everything that your Dockerfile builds in the /app directory and replaces it with whatever's in your local system. If your host doesn't have a ./app/frontend/dist then your container won't have that path either, regardless of whatever the Dockerfile does.
I would generally recommend just deleting this volumes: block entirely. It introduces an awkward live-development path (where all of your tooling needs to know that the actual service runs in Docker) and simultaneously isn't what you'd run in development (you want the image to be self-contained and not to need to copy the application separately from the image).

Answer 2

In your compose file, you set a volume which is going to replace your local environment with the one in your container even after npm run build
volumes:
- ./app:/app
You can either build it in your local or remove volumes

Answer 3

We had a similar issue with a nestjs build. Lately we noticed, that we had excluded the src file in the .dockerignore.

Answer 4

Issue is not with docker file. It issue with your dependency. please check package.json file in root folder.