Locked package.json files in Docker container using docker-compose

Question

I'm using Docker for Mac and Docker Compose for development of a Node.js application and I'm experiencing an error with the package.json file being locked. The specific error after running npm install --save <package> within a running container is:

npm WARN saveError EBUSY: resource busy or locked, rename
'/Example/package.json.1647356251' -> '/Example/package.json'

The simplified package structure is:

▾ docker/
    Dockerfile
  docker-compose.yaml
  package.json

The Dockerfile contains:

FROM node:9.5
ENV SOURCE_CODE /Example
COPY package.json $SOURCE_CODE/package.json
RUN npm --prefix $SOURCE_CODE install $SOURCE_CODE
WORKDIR $SOURCE_CODE

The docker-compose.yaml file contains:

version: "3"

services:
  node:
    build:
      context: ./
      dockerfile: ./docker/Dockerfile
    volumes:
      - ./node_modules/:/Example/node_modules/
      - ./package.json:/Example/package.json

The package.json file contains:

{
  "name": "example",
  "version": "1.0.0",
  "description": "example",
  "license": "UNLICENSED"
}

Running docker-compose run --entrypoint bash node to start bash, then running npm install --save redux inside the container yields the warning about the package.json file being locked, however files are able to be written in the node_modules directory on the host. How can I avoid locks on package.json file using this structure?

Answer 1

I encountered the same issue and I solved this by mounting the folder where package.json is located instead of package.json itself.

version: "3"

services:
  node:
    build:
      context: ./
      dockerfile: ./docker/Dockerfile
    volumes:
      - .:/Example

Mounting package.json directly as a volume seems to lock the file.