instruction: Create a comprehensive Dockerfile for networking applications with best practices
output: ```dockerfile
  from the default
  bridge network, you need to stop the container and recreate it with different
  network options.Each user-defined network creates a configurable bridge.If your containers use the default bridge network, you can configure it, but
  all the containers use the same settings, such as MTU and iptables rules.
  In addition, configuring the default bridge network happens outside of Docker
  itself, and requires a restart of Docker.User-defined bridge networks are created and configured using
  docker network create. If different groups of applications have different
  network requirements, you can configure each user-defined bridge separately,
  as you create it.Linked containers on the default bridge network share environment variables.Originally, the only way to share environment variables between two containers
  was to link them using the --link flag. This type of
  variable sharing isn't possible with user-defined networks. However, there
  are superior ways to share environment variables. A few ideas:Multiple containers can mount a file or directory containing the shared
  information, using a Docker volume.Multiple containers can be started together using docker-compose and the
  compose file can define the shared variables.You can use swarm services instead of standalone containers, and take
  advantage of shared
  secrets and
  configs.Containers connected to the same user-defined bridge network effectively expose all ports
  to each other. For a port to be accessible to containers or non-Docker hosts on
  different networks, that port must be published using the -p or --publish
  flag.OptionsThe following table describes the driver-specific options that you can pass to
  --opt when creating a custom network using the bridge driver.OptionDefaultDescriptioncom.docker.network.bridge.nameInterface name to use when creating the Linux bridge.com.docker.network.bridge.enable_ip_masqueradetrueEnable IP masquerading.com.docker.network.bridge.gateway_mode_ipv4com.docker.network.bridge.gateway_mode_ipv6natControl external connectivity. See Packet filtering and firewalls.com.docker.network.bridge.enable_icctrueEnable or Disable inter-container connectivity.com.docker.network.bridge.host_binding_ipv4all IPv4 and IPv6 addressesDefault IP when binding container ports.com.docker.network.driver.mtu0 (no limit)Set the containers network Maximum Transmission Unit (MTU).com.docker.network.container_iface_prefixethSet a custom prefix for container interfaces.com.docker.network.bridge.inhibit_ipv4falsePrevent Docker
  ```