title: Docker error : Cannot start service angular , listen tcp 0.0.0.0:4200 already in use
body: <p>There is nothing mounted on port 3000 and 4200 and i stopped all containers just in case also.
  When i do docker-compose up i get this error </p>
  
  <pre><code> ERROR: for angular  Cannot start service angular: driver failed programming external connectivity on endpoint leapmotionreal_angular_1 (fd6858f87fb4db419407ae981758fdc8cdaa72d654db9b5aff91ccc8f6c4d1c8): Error starting userland proxy: listen tcp 0.0.0.0:4200: bind: address already in use
  </code></pre>
  
  <p>And the front end is starts on port on 4200 but my backend doesnt and instead of logging it throws the mentioned error above.</p>
  
  <p>My app structure looks like this .</p>
  
  <pre><code>~root 
     all angular files here in root
     Server folder with node js files &gt; Dockerfile.yml(for node)
     docker-compose.yml
     Dockerfile.yml
  </code></pre>
  
  <p>docker-compose.yml</p>
  
  <pre><code>version: '3.0'
  
  services:
    angular: 
      build: 
        context: ./
        dockerfile: Dockerfile
      ports: ["4200:4200"]
  
    express: 
      build: 
        context: ./Server/
        dockerfile: ./Server/Dockerfile
      ports: ["3000:3000"]
  </code></pre>
  
  <p>Dockerfile for angular </p>
  
  <pre><code>FROM node
  
  RUN mkdir -p /usr/src/app/client
  
  WORKDIR /usr/src/app/client
  
  COPY package.json /usr/src/app/client
  
  RUN npm cache verify &amp;&amp; npm install
  
  COPY . /usr/src/app/client
  
  EXPOSE 4200:4200
  
  CMD ["ng","serve"]
  </code></pre>
  
  <p>Dockerfile for node js app(my Server folder)</p>
  
  <pre><code>FROM node
  
  RUN mkdir -p /usr/src/app/server
  
  WORKDIR /usr/src/app/server
  
  COPY package.json /usr/src/app/server
  
  RUN npm cache verify &amp;&amp; npm install
  
  COPY . /usr/src/app/server
  
  EXPOSE 3000:3000
  
  CMD ["npm","start"]
  </code></pre>