Answers

Here are example answers for the questions of this chapter:

1. The three core elements of the Docker CNM are as follows:
   • Sandbox: A network namespace for a container where its network stack resides
   • Endpoint: An interface that connects a container to a network
   • Network: A collection of endpoints that can communicate with each other directly
2. To create a custom Docker bridge network called frontend, you can use the docker network create command with the --driver flag set to bridge (which is the default driver) and the --subnet flag to specify the subnet for the network. Here’s an example command:

   $ docker network create --driver bridge \    --subnet 172.25.0.0/16 frontend

This will create a bridge network named frontend with a subnet of 172.25.0.0/16. You can then use this network when starting containers with the --network option:

$ docker run --network frontend <docker-image>

3. To run two nginx:alpine containers attached to...