title: Docker: Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432?
body: <p>I am getting issues while setup and run the docker instance on my local system with Ruby on Rail. Please see my docker configuration files:-</p>
  
  <p>Dockerfile</p>
  
  <pre><code>FROM ruby:2.3.1
  
  RUN useradd -ms /bin/bash web
  RUN apt-get update -qq &amp;&amp; apt-get install -y build-essential
  RUN apt-get -y install nginx
  RUN apt-get -y install sudo
  # for postgres
  RUN apt-get install -y libpq-dev
  
  # for nokogiri
  RUN apt-get install -y libxml2-dev libxslt1-dev
  
  # for a JS runtime
  RUN apt-get install -y nodejs
  RUN apt-get update
  
  # For docker cache
  WORKDIR /tmp 
  ADD ./Gemfile Gemfile
  ADD ./Gemfile.lock Gemfile.lock
  ENV BUNDLE_PATH /bundle
  RUN gem install bundler --no-rdoc --no-ri
  RUN bundle install
  # END
  ENV APP_HOME /home/web/cluetap_app
  RUN mkdir -p $APP_HOME
  WORKDIR $APP_HOME
  ADD . $APP_HOME
  RUN chown -R web:web $APP_HOME
  ADD ./nginx/nginx.conf /etc/nginx/
  RUN unlink /etc/nginx/sites-enabled/default
  ADD ./nginx/cluetap_nginx.conf /etc/nginx/sites-available/
  RUN ln -s /etc/nginx/sites-available/cluetap_nginx.conf /etc/nginx/sites-enabled/cluetap_nginx.conf
  RUN usermod -a -G sudo web
  </code></pre>
  
  <p>docker-compose.yml</p>
  
  <pre><code>version: '2'
  services:
    postgres:
      image: 'postgres:9.6'
      environment:
        - PGDATA=/var/lib/postgresql/data/pgdata
        - POSTGRES_PASSWORD=
        - POSTGRES_USER=postgres
        - POSTGRES_HOST=cluetapapi_postgres_1
      networks:
        - default
        - service-proxy
      ports:
        - '5432:5432'
      volumes:
        - 'postgres:/var/lib/postgresql/data'
      labels:
        description: "Postgresql Database"
        service: "postgresql"
    web:
      container_name: cluetap_api
      build: .
      command: bash -c "thin start -C config/thin/development.yml &amp;&amp; nginx -g 'daemon off;'"
      volumes:
        - .:/home/web/cluetap_app
      ports:
        - "80:80"
      depends_on:
        - 'postgres'
  networks:
    service-proxy:
  volumes:
    postgres:
  </code></pre>
  
  <p>When I have run <strong>docker-compose build</strong> and <strong>docker-compose up -d</strong> these two commands it run succesfully but when I have hit from the url the it thorught <strong>internal server error</strong> and the error is </p>
  
  <pre><code>Unexpected error while processing request: could not connect to server: Connection refused
      Is the server running on host "localhost" (127.0.0.1) and accepting
      TCP/IP connections on port 5432?
  could not connect to server: Cannot assign requested address
      Is the server running on host "localhost" (::1) and accepting
      TCP/IP connections on port 5432?
  </code></pre>
  
  <p>I have applied some solution but it did not work for me, please guide me I am new to docker and AWS.</p>