'Cannot find module "express" - docker-compose nodejs service

I'm running a small nodejs microservice in docker. When I run the container standalone with docker run -p 3000:3000 {image-name} it works fine. However when I attempt to run it from docker-compose, I get the following error:

user_1     | Error: Cannot find module 'express'
user_1     | Require stack:
user_1     | - /usr/src/app/src/app.js
user_1     |     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
user_1     |     at Function.Module._load (internal/modules/cjs/loader.js:667:27)
user_1     |     at Module.require (internal/modules/cjs/loader.js:887:19)
user_1     |     at require (internal/modules/cjs/helpers.js:74:18)
user_1     |     at Object.<anonymous> (/usr/src/app/src/app.js:12:17)
user_1     |     at Module._compile (internal/modules/cjs/loader.js:999:30)
user_1     |     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
user_1     |     at Module.load (internal/modules/cjs/loader.js:863:32)
user_1     |     at Function.Module._load (internal/modules/cjs/loader.js:708:14)
user_1     |     at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12) {
user_1     |   code: 'MODULE_NOT_FOUND',
user_1     |   requireStack: [ '/usr/src/app/src/app.js' ]
user_1     | }

Here is the Dockerfile for the node service I'm trying to run

FROM node:12

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

COPY package.json /usr/src/app

# Install npm packages
RUN npm install

COPY . /usr/src/app


EXPOSE 3000

CMD ["npm", "run", "dev"]

To add, express is defined as a dependency in the package.json file, it's not that.

Here is the docker-compose.yml (Relevant snippet)

    user: 
        build: ./user-service
        ports: 
            - "2008:3000"
        volumes:
            - type: bind
              source: ./user-service
              target: /usr/src/app
        working_dir: /usr/src/app
        networks: 
            - backend

    redis: 
        image: "redis:latest"
        ports: 
            - "6379:6379"
        networks:
            - backend

The reason I bind the volume is because I want to hot reload the application whenever I make a change.

What I've tried:

  • Rebuilding the image

  • opening a shell inside the container to ensure the files are mapped out correctly - they are.

  • clearing all my cache and images, and rebuilding everything just to be sure nothing is cached.

node.jsdockerexpressdocker-compose


Solution 1:[1]

I had the same problem recently, and solved it by creating an anonymous volume for the node_modules folder to prevent it from being overwritten:

volumes: 
  - ./node:/usr/src/app
  # Anonymous volume:
  - /usr/src/app/node_modules

You also need to give permissions to the node user to access the volume:

RUN chown -R node:node node_modules

Solution 2:[2]

docker container is not found your node_modules directory

So you have to manually run the npm install inside of your docker image

docker-compose run user npm install

format: docker-compose run [image_name] [command]

command: npm install

In your example

     user:  //image name
        build: ./user-service
        ports: 
            - "2008:3000"
        volumes:
            - type: bind
              source: ./user-service
              target: /usr/src/app
        working_dir: /usr/src/app
        networks: 
            - backend

    redis: //image name
        image: "redis:latest"
        ports: 
            - "6379:6379"
        networks:
            - backend

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Mário Queiroz
Solution 2 Karthikeyan Ganesan

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