instruction: Create a comprehensive Dockerfile for networking applications with best practices
output: ```dockerfile
  from a user-defined bridge, Docker uses tools specific to the
  operating system to manage the underlying network infrastructure (such as adding
  or removing bridge devices or configuring iptables rules on Linux). These
  details should be considered implementation details. Let Docker manage your
  user-defined networks for you.Connect a container to a user-defined bridgeWhen you create a new container, you can specify one or more --network flags.
  This example connects an Nginx container to the my-net network. It also
  publishes port 80 in the container to port 8080 on the Docker host, so external
  clients can access that port. Any other container connected to the my-net
  network has access to all ports on the my-nginx container, and vice versa.
  
  $ docker create --name my-nginx \
   --network my-net \
   --publish 8080:80 \
   nginx:latest
  To connect a running container to an existing user-defined bridge, use the
  docker network connect command. The following command connects an already-running
  my-nginx container to an already-existing my-net network:
  
  $ docker network connect my-net my-nginx
  <h2 class=scroll-mt-20 id=disconnect-a-container-
  ```