What is Docker network?

What is Docker Network?

Docker network is a virtual network that allows Docker containers to communicate with each other and with the host system. It provides a way to manage the network connectivity of Docker containers, allowing them to be isolated from each other or connected to the same network, as needed.

Docker Network Drivers

Docker provides several network drivers that you can use to create and manage networks. The most common network drivers are:

Bridge Network: This is the default network driver in Docker. It creates a virtual bridge on the host system and attaches containers to it. Containers on the same bridge network can communicate with each other, while containers on different bridge networks are isolated.

graph LR Host -- Bridge Network --> Container1 Host -- Bridge Network --> Container2 Container1 -- Can Communicate --> Container2

Host Network: This network driver allows a container to use the host's network stack directly, effectively bypassing the Docker network. This can be useful for performance-sensitive applications that need low-level network access.

graph LR Host -- Host Network --> Container Container -- Can Communicate --> Host Network

Overlay Network: This network driver allows containers running on different Docker hosts to communicate with each other. It creates a virtual network that spans multiple Docker hosts, enabling containers to connect to the same logical network regardless of their physical location.

graph LR DockerHost1 -- Overlay Network --> Container1 DockerHost2 -- Overlay Network --> Container2 Container1 -- Can Communicate --> Container2

Macvlan Network: This network driver allows you to assign a MAC address to a container, making it appear as a physical network interface on the host. This can be useful for legacy applications that require direct access to the network.

graph LR Host -- Macvlan Network --> Container Container -- Can Communicate --> Host Network

Network Isolation and Connectivity

Docker networks provide a way to control the network connectivity of your containers. You can create separate networks for different services or applications, and then connect the relevant containers to those networks. This allows you to isolate different parts of your application and control the flow of network traffic.

For example, you might have a web application that needs to communicate with a database. You could create two separate networks: one for the web application and one for the database. The web application containers would be connected to the web network, and the database containers would be connected to the database network. This would ensure that the web application can only communicate with the database, and not with any other services or applications on the host.

graph LR WebNetwork -- Web Application --> Database DatabaseNetwork -- Database --> WebNetwork WebNetwork -- Isolated --> DatabaseNetwork

By using Docker networks, you can easily manage the network connectivity of your containers, improve security, and simplify the deployment and scaling of your applications.