In this module, we will explore Docker networking in depth. Understanding Docker networking is crucial for creating scalable and efficient containerized applications. We will cover the following topics:

1. Docker Networking Overview
2. Types of Docker Networks
3. Creating and Managing Docker Networks
4. Connecting Containers to Networks
5. Network Configuration Options
6. Practical Examples and Exercises

Docker networking allows containers to communicate with each other and with external systems. It provides various networking options to suit different use cases, from simple single-host setups to complex multi-host configurations.

• Container Network Model (CNM): Docker's networking model that provides a consistent way to manage networking for containers.
• Network Drivers: Plugins that implement the network functionality. Docker includes several built-in drivers.

Docker supports several types of networks, each with its own use cases and characteristics:

You can create a Docker network using the docker network create command. For example, to create a bridge network:

To list all Docker networks:

To inspect a specific network and view its details:

To remove a Docker network:

When you create a container, you can specify the network it should connect to using the --network option:

You can also connect an existing container to a network:

And disconnect it:

Docker provides several options to configure networks:

• Subnets and IP Ranges: You can specify custom subnets and IP ranges for your networks.
• Gateways: Define custom gateways for your networks.
• DNS Servers: Configure custom DNS servers for name resolution within the network.

1. Create a bridge network:

   docker network create my_bridge_network
   

2. Run two containers on this network:

   docker run -d --name container1 --network my_bridge_network nginx
   docker run -d --name container2 --network my_bridge_network nginx
   

3. Verify that the containers can communicate:

   docker exec container1 ping container2
   

1. Create a custom bridge network with a specific subnet:

   docker network create --subnet=172.18.0.0/16 my_custom_bridge
   

2. Run a container on this network:

   docker run -d --name my_custom_container --network my_custom_bridge nginx
   

3. Verify the container's IP address and connectivity:

   docker inspect my_custom_container
   docker exec my_custom_container ping 172.18.0.1
   

1. Create the network:

   docker network create --subnet=172.18.0.0/16 my_custom_bridge
   

2. Run the container:

   docker run -d --name my_custom_container --network my_custom_bridge nginx
   

3. Verify the IP address and connectivity:

   docker inspect my_custom_container
   docker exec my_custom_container ping 172.18.0.1
   

In this module, we delved into Docker networking, covering the different types of networks, how to create and manage them, and how to connect containers to networks. Understanding these concepts is essential for building robust and scalable containerized applications. In the next module, we will explore Docker storage options in detail.