title: Docker not propagating file changes from host to container
body: <p>I am aiming to configure docker so that when I modify a file on the host the change is propagated  inside the container file system.</p>
  
  <p>You can think of this as hot reloading for server side node code.</p>
  
  <p>The nodemon file watcher <em>should</em> restart the server in response to file changes. </p>
  
  <p>However these file changes on the host volume don't seem to be reflected inside the container when I inspect the container using docker exec pokerspace_express_1 bash and inspect a modified file the changes are not propagated inside the container from the host.</p>
  
  <p><em>Dockerfile</em></p>
  
  <pre><code>FROM node:8
  
  MAINTAINER therewillbecode
  
  # Create app directory
  WORKDIR src/app
  
  RUN npm install nodemon -g
  
  # Install app dependencies
  COPY package.json .
  # For npm@5 or later, copy package-lock.json as well
  # COPY package.json package-lock.json ./
  
  RUN npm install
  
  
  CMD [ "npm", "start" ]
  </code></pre>
  
  <p><em>docker-compose.yml</em></p>
  
  <pre><code>version: '2'
  services:
    express:
     build: .
     depends_on:
      - mongo
     environment:
      - MONGO_URL=mongo:27017/test
      - SERVER_PORT=3000
     volumes:
      - ./:/src/app
     ports:
      - '3000:3000'
     links:
      - mongo
  
    mongo:
      image: mongo
      ports:
       - '27017:27017'
  
    mongo-seed:
      build: ./mongo-seed
      links:
       - mongo
  </code></pre>
  
  <p><em>.dockerignore</em></p>
  
  <pre><code>.git
  .gitignore
  README.md
  docker-compose.yml
  </code></pre>
  
  <p>How can I ensure that host volume file changes are reflected in the container?</p>