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Redis – 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.

Tags:

4

Answers


  1. 0

    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
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  2. 0

    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
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  3. 0

    Bring down all containers

    docker compose down -v

    In your docker-compose.yml file map node_volumes directory

    volumes:
    - .:/usr/src/app
    - /usr/src/app/node_modules

    Build and run containers. (Ensure to delete node_modules directory in root of nodejs app in dockerhost)

    docker compose build --no-cache
docker compose up -d

    refer https://stackoverflow.com/a/45413240/8811037 for more details

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  4. 0

    Bring down all containers, remove persistant volumes if any.

    docker compose down -v

    In your docker-compose.yml file map node_volumes directory

    volumes:
    - .:/usr/src/app
    - /usr/src/app/node_modules

    Build and run containers. (Ensure to delete node_modules directory in root of nodejs app in dockerhost)

    docker compose build --no-cache
docker compose up -d

    refer https://stackoverflow.com/a/45413240/8811037 for more details

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