instruction: Create a comprehensive Dockerfile for networking applications with best practices
output: ```dockerfile
  from a single disk
  image.Declarative service modelDocker Engine uses a declarative approach to
  let you define the desired state of the various services in your application
  stack. For example, you might describe an application comprised of a web front
  end service with message queueing services and a database backend.ScalingFor each service, you can declare the number of tasks you want to
  run. When you scale up or down, the swarm manager automatically adapts by
  adding or removing tasks to maintain the desired state.Desired state reconciliationThe swarm manager node constantly monitors
  the cluster state and reconciles any differences between the actual state and your
  expressed desired state. For example, if you set up a service to run 10
  replicas of a container, and a worker machine hosting two of those replicas
  crashes, the manager creates two new replicas to replace the replicas that
  crashed. The swarm manager assigns the new replicas to workers that are
  running and available.Multi-host networkingYou can specify an overlay network for your
  services. The swarm manager automatically assigns addresses to the containers
  on the overlay network when it initializes or updates the application.Service discoverySwarm manager nodes assign each service in the swarm a
  unique DNS name and load balance running containers. You can query every
  container running in the swarm through a DNS server embedded in the swarm.Load balancingYou can expose the ports for services to an
  external load balancer. Internally, the swarm lets you specify how to distribute
  service containers between nodes.Secure by defaultEach node in the swarm enforces TLS mutual
  authentication and encryption to secure communications between itself and all
  other nodes. You have the option to use self-signed root certificates or
  certificates
  ```