I am currently setting up a Docker container that will be used to Debug a NodeJS application. This container needs to support live-reloading (using nodemon) and needs to be a Linux container (my workstation is a Windows machine).
My current setup is the following:
Dockerfile.debug
FROM node:current-alpine
VOLUME /app
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production --registry=http://172.16.102.123:8182/repository/npm/
RUN npm install -g nodemon
ENV NODE_ENV=test
EXPOSE 8000
EXPOSE 9229
CMD [ "nodemon", "--inspect=0.0.0.0:9229", "--ignore", "dist/test/**/*.js", "dist/index.js" ]
docker-compose.yml
version: '3'
services:
app:
build:
context: .
dockerfile: Dockerfile.debug
volumes:
- .:/app
- /app/node_modules
ports:
- 8000:8000
Everything works fine except the dependencies because some of these are plattform specific. That means, it is not possible to simply mount the node_modules directory into the container (like I do with the rest of the codebase). I tried setting up my files in such a way, that the dependencies are different for each platform but I either end up with an empty node_modules directory or with the node_modules directory from the host (the current set up gives me an empty directory). Does anybody know how to fix my problem? I have looked at other solutions (like this one) but they did not work.
Related
I am currently running a nodejs express app in docker.
docker-compose.yml
# networks and nginx ...
api:
build:
context: ./api
networks:
- back-tier
volumes:
- ./api:/usr/src/api
- /usr/src/api/node_modules
Dockerfile
FROM node:lts-alpine
RUN npm install -g nodemon
WORKDIR /usr/src/api
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 8080
CMD [ "nodemon" ]
The problem here is the volume is mounted and I can't modify package.json from the host as the docker "owns" package.json.
However if I add a dependency inside the docker with docker run -it dockername_api /bin/sh then doing npm i package, the package.json does not update in the host side.
The solution now is to manually copy package.json from the container back to host after adding a new dependency? Another way of doing it is to stop the docker, do npm i package on the host, then rebuild the docker, which is very cumbersome.
Thanks
I am trying to host a development environment on my Windows machine which hosts a frontend and backend container. So far I have only been working on the backend. All files are on the C Drive which is shared via Docker Desktop.
I have the following docker-compose file and Dockerfile, the latter is inside a directory called backend within the root directory.
Dockerfile:
FROM node:12.15.0-alpine
WORKDIR /usr/app
COPY package*.json ./
RUN npm install
EXPOSE 5000
CMD [ "npm", "start" ]
docker-compose.yml:
version: "3"
services:
backend:
container_name: backend
build:
context: ./backend
dockerfile: Dockerfile
volumes:
- ./backend:/usr/app
environment:
- APP_PORT=80
ports:
- '5000:5000'
client:
container_name: client
build:
context: ./client
dockerfile: Dockerfile
volumes:
- ./client:/app
ports:
- '80:8080'
For some reason, when I make changes in my local files they are not reflecting inside the container. I am testing this by slightly modifying the outputs of one of my files, but I am having to rebuild the container each time to see the changes take effect.
I have worked with Docker in PHP applications before, and have basically done the same thing. So I am unsure why this is not working with by Node.js app. I am wondering if I am just missing something glaringly obvious as to why this is not working.
Any help would be appreciated.
The difference between node and PHP here is that php automatically picks up file system changes between requests, but a node server doesn't.
I think you'll see that the file changes get picked up if you restart node by bouncing the container with docker-compose down then up (no need to rebuild things!).
If you want node to pick up file system changes without needing to bounce the server you can use some of the node tooling. nodemon is one: https://www.npmjs.com/package/nodemon. Follow the installation instructions for local installation and update your start script to use nodemon instead of node.
Plus I really do think you have a mistake in your dockerfile and you need to copy the source code into your working directory. I'm assuming you got your initial recipe from here: https://dev.to/alex_barashkov/using-docker-for-nodejs-in-development-and-production-3cgp. This is the docker file is below. You missed a step!
FROM node:10-alpine
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
COPY . .
CMD [ "npm", "start" ]
I've been working with docker some weeks ago and I was able to hold this issue, stop docker containers and start them over again to see the changes that I had made in my code but now is really anoying because every single change I do have to kill docker and then "docker-compose up".
However my friend is using the same container on his apple machine but when he makes changes to any server side code he does not have to restart his app.
I can see the changes when I go into the container but those changes are not reflected on live(browser).
My Dockerfile
FROM node:8.11.3
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
# Copy application files
COPY tools ./tools/
COPY migrations ./migrations/
COPY seeds ./seeds/
# Attempts to copy "build" folder even if it doesn't exist
COPY .env build* ./build/
RUN npm install -g nodemon
RUN git clone https://github.com/vishnubob/wait-for-it.git
EXPOSE 8080
CMD ["nodemon", "-L", "server"]
My docker-compose.yml
api:
build: ./
hostname: api
container_name: api
ports:
- "${APP_PORT}:3000"
volumes:
- ./:/usr/src/app
env_file:
- ".env"
command: node tools/run.js
Any sugestion?
I am building a set of connected node services using docker-compose and can't figure out the best way to handle node modules. Here's what should happen in a perfect world:
Full install of node_modules in each container happens on initial build via each service's Dockerfile
Node modules are cached after the initial load -- i.e. functionality so that npm only installs when package.json has changed
There is a clear method for installing npm modules -- whether it needs to be rebuilt or there is an easier way
Right now, whenever I npm install --save some-module and subsequently run docker-compose build or docker-compose up --build, I end up with the module not actually being installed.
Here is one of the Dockerfiles
FROM node:latest
# Create app directory
WORKDIR /home/app/api-gateway
# Intall app dependencies (and cache if package.json is unchanged)
COPY package.json .
RUN npm install
# Bundle app source
COPY . .
# Run the start command
CMD [ "npm", "dev" ]
and here is the docker-compose.myl
version: '3'
services:
users-db:
container_name: users-db
build: ./users-db
ports:
- '27018:27017'
healthcheck:
test: exit 0'
api-gateway:
container_name: api-gateway
build: ./api-gateway
command: npm run dev
volumes:
- './api-gateway:/home/app/api-gateway'
- /home/app/api-gateway/node_modules
ports:
- '3000:3000'
depends_on:
- users-db
links:
- users-db
It looks like this line might be overwriting your node_modules directory:
# Bundle app source
COPY . .
If you ran npm install on your host machine before running docker build to create the image, you have a node_modules directory on your host machine that is being copied into your container.
What I like to do to address this problem is copy the individual code directories and files only, eg:
# Copy each directory and file
COPY ./src ./src
COPY ./index.js ./index.js
If you have a lot of files and directories this can get cumbersome, so another method would be to add node_modules to your .dockerignore file. This way it gets ignored by Docker during the build.
I'm attempting to convert a Node app to using Docker but running into a few issues/questions I'm unable to answer.
But for simplicity I've included some very basic example files to keep the question on target. In fact the example below merely links to a Mongo container but doesn't use it in the code to keep it even simpler.
Primarily, what Dockerfile and docker-compose.yml setup is required to successfully use Docker on a Node + Express + Mongo app on both local (OS X) development and for Production builds?
Dockerfile
FROM node:6.3.0
# Create new user to avoid using root - is this correct practise?
RUN useradd --user-group --create-home --shell /bin/false app
COPY package.json /home/app/code/
RUN chown -R app:app /home/app/*
USER app
WORKDIR /home/app/code
# Should this even be set here or use docker-compose instead?
# And should there be:
# - docker-compose.yml setting it to production by default
# - docker-compose.dev.yml setting it to production?
# Or reverse it? (docker-compose.prod.yml instead with default being development?)
# Commenting below out or it will always run as production
#ENV NODE_ENV production
RUN npm install
USER root
COPY . /home/app/code
# Running chown to ensure new 'app' user owns files
RUN chown -R app:app /home/app/*
USER app
EXPOSE 3000
# What CMD should be here to ensure development versus production is simple?
# Development - Restart server and refresh browser on file changes
# Production - Ensure uptime.
CMD ["npm", "start"]
docker-compose.yml
version: "2"
services:
web:
build: .
# I would normally use a .env file but for this example will set explicitly
# env_file: .env
environment:
- NODE_ENV=production
volumes:
- ./:/home/app/code
- /home/app/code/node_modules
ports:
- "3000:3000"
links:
- mongo
mongo:
image: mongo
ports:
- "27017:27017"
docker-compose.dev.yml
version: "2"
services:
web:
# I would normally use a .env file but for this example will set explicitly
# env_file: .env
environment:
- NODE_ENV=development
package.json
{
"name": "docker-node-test",
"version": "1.0.0",
"description": "",
"main": "app.js",
"scripts": {
"start": "nodemon app.js"
},
"dependencies": {
"express": "^4.14.0",
"mongoose": "^4.6.1",
"nodemon": "^1.10.2"
},
"devDependencies": {
"mocha": "^3.0.2"
}
}
1. How to handle the different NODE_ENV (dev, production, staging)?
This is my primary question and conundrum.
In the example I’ve used the NODE_ENV is set in the Dockerfile as production and there are two docker-compose files:
docker-compose.yml sets the defaults include NODE_ENV to production
docker-compose.dev.yml overrides the NODE_ENV and sets it to development
1.1. Is it advised to rather switch that order around and have development settings as the default and instead use a docker-compose.prod.yml for overrides?
1.2. How do you handle the node_modules directory?
I'm really not sure how to handle the node_modules directory at all between local development needs and then running for Production. (Perhaps I have a fundamental misunderstanding though?)
Edit:
I added a .dockerignore file and included the node_modules directory as a line. This ensures the node_modules dir is ignored during the copy, etc.
I then edited the docker-compose.yml to include the node_modules as a volume.
volumes:
- ./:/home/app/code
- /home/app/code/node_modules
I have also put the above change into the full docker-compose.yml at the start of the question for completeness.
Is this even a solution?
Doing the above ensured I could have my local development npm install included dev-dependencies. And when running docker-compose up it pulls in the production only node modules inside the Docker container (since the default docker-compose.yml is set to NODE_ENV=production).
But it seems the NODE_ENV set inside the 2 docker-compose files aren't taken into account when running docker-compose -f docker-compose.yml build :/ I expected it to send NODE_ENV=production but ALL of the node_modules are re-installed (including the dev-dependencies).
Do we instead use 2 Dockerfiles? (Dockerfile for Prod; Dockerfile.dev for local development)
(I feel like that is a fundamental piece of logic/knowledge I am missing in the setup)
2. Nodemon vs PM2
How would one use nodemon on the local development machine but PM2 on the Production build?
3. Should you create a user inside the docker containers and then set that user to be used in the Dockerfile?
It uses root user by default but I’ve not seen many articles talking about creating a dedicated user within the container. Am I correct in what I’ve done for security? I certainly wouldn’t feel comfortable running an app as root on a non-Docker build.
Thank you for reading. Any and all assistance appreciated :)
I can share my experience, not saying it is the best solution.
I have Dockerfile and dockerfile.dev. In dockerfile.dev I install nodemon and run the app with nodemon, the NODE_ENV doesn't seem to have any impact. As for users you should not use root for security reasons. My dev version:
FROM node:16.14.0-alpine3.15
ENV NODE_ENV=development
# install missing libs and python3
RUN apk update && apk add -U unzip zip curl && rm -rf
/var/cache/apk/* && npm i node-gyp#8.4.1 nodemon#2.0.15 -g
WORKDIR /node
COPY package.json package-lock.json ./
RUN mkdir /app && chown -R node:node .
USER node
RUN npm install && npm cache clean --force
WORKDIR /node/app
COPY --chown=node:node . .
# local development
CMD ["nodemon", "server.js" ]
in Production I run the app with node:
FROM node:16.14.0-alpine
ENV NODE_ENV=production
# install missing libs and python3
RUN apk update && apk add -U unzip zip curl && rm -rf /var/cache/apk/* \
&& npm i node-gyp#8.4.1 -g
WORKDIR /node
COPY package.json package-lock.json ./
RUN mkdir /app && chown -R node:node .
USER node
RUN npm install && npm cache clean --force
WORKDIR /node/app
COPY --chown=node:node . .
CMD ["node", "server.js" ]
I have two separate versions of docker-compose. In docker-compose.dev.yml I set the dockerfile to dockerfile.dev:
app:
depends_on:
mongodb:
condition: service_healthy
build:
context: .
dockerfile: Dockerfile.dev
healthcheck:
test: [ "CMD", "curl", "-f", "http://localhost:5000" ]
interval: 180s
timeout: 10s
retries: 5
restart: always
env_file: ./.env
ports:
- "5000:5000"
environment:
...
volumes:
- /node/app/node_modules
In production docker-compose.yml there is the dockerfile set to Dockerfile.
Nodemon vs PM2. I used pm2 before dockerizing the app. I cannot see any benefit of having it in docker, the restart: always takes care about restarting on error. You should better use restart: unless_stopped but I prefer the always option. Initially I used nodemon also on production so that the app reflected the volumes changes but I skipped this because the restart didn't work well (it was waiting for some code changes..).
Users: You can see it in my example. I took a course for docker + nodejs and setting a non-root user was recommended so I do it and I have no problems.
I hope I explained well enough and it can help you. Good luck.
Either, it doesn't matter too much, I prefer to have development details then overwrite with production details.
I don't commit them to my repo, then I have "npm install" in my dockerfile.
You can set rules in the dockerfile to which one to build based on build settings.
It is typical to build everything via root, and run the main program via root. You can set up other users, but for most uses it is not needed as the idea of docker containers is to isolate each process in individual docker containers.