Dockerizing NodeJS——保留节点模块

Question

I have an NodeJS express app that I want to dockerize. For that I created a Dockerfile :

FROM node:18 AS server
ENV NODE_ENV=production
WORKDIR /app
COPY package*.json /
RUN npm ci
COPY . .

I also have a .dockerignore file:

node_modules/
client/node_modules/

Dockerfile
docker-compose.yml
.git
.gitignore
.dockerignore
.env

All is run with a help of docker-compose.yml :

version: '3.8'
services:
  app:
    container_name: my-app
    image: my-org/my-app
    build:
      context: .
      dockerfile: Dockerfile
    command: node index.js
    ports:
      - "3030:3030"
    environment:
      HELLO: world
    env_file:
      - .env

When I run the Dockerfile commands in this order, the COPY. . COPY. . seems to remove the node_modules from the image, that are created with npm ci that runs beforehand. I've tried it with first running COPY. . COPY. . and then npm ci and node_modules stays in the image.

My question is – is it better to run npm ci before COPY. . COPY. . , and if the answer is yes, then how can I make the node_modules stay?

Answer 1

I had a similar problem and used for that a "build container".

You ignored the node_modules folder in your .dockerignore . Therfore it does not get copied in your image.

# The instructions for the first stage
FROM node:16-alpine as builder

ARG NODE_ENV=production
ENV NODE_ENV=${NODE_ENV}

RUN apk --no-cache add python3 make g++

COPY ./package*.json ./
RUN npm install


# ------------------------------------


# The instructions for second stage
FROM node:16-alpine

WORKDIR /opt/OpenHaus/backend
COPY --from=builder node_modules node_modules
RUN apk --no-cache add openssl

COPY . ./
#COPY ./package.json ./

#ENV HTTP_PORT=8080
ENV NODE_ENV=production
#ENV DB_HOST=10.0.0.1
#EXPOSE 8080

CMD ["node", "index.js"]

With that the dependencies are "build" and copied from the build container inside your node.js image.

More to read:

• https://medium.com/@kahana.hagai/docker-compose-with-node-js-and-mongodb-dbdadab5ce0a
• https://dev.to/alex_barashkov/using-docker-for-nodejs-in-development-and-production-3cgp