Understanding Docker Networking and its Types – StarAgile

Network administrators have a significant responsibility in the Docker ecosystem to comprehend the network components found in virtualization platforms such as Microsoft, Red Hat, etc. To correctly configure a container architecture, however, deployment of a container is not simple; it requires strong networking skills. To address this problem, Docker Networking was developed.

 Before discussing Docker Networking, let’s quickly define the term Docker. Docker is an open development, distribution, and execution platform for applications. Docker facilitates the separation of your applications and infrastructure, enabling quick software delivery. Using Docker, you can manage your infrastructure similarly to how you manage your applications. By using Docker’s techniques for fast shipping, testing, and deploying code, you may significantly reduce the time between generating code and delivering it to production.

What is docker networking ?

 A networking layer is required for Docker containers to connect with one other and the outside world through the host system. Docker supports many network types, each suited to certain use cases.

 For instance, an application that runs on a single Docker container networking would have a different network configuration than a web application with a cluster consisting of a database, application, and load balancers that span numerous containers and must interact. Additionally, other clients will need to access the web application container.

 Docker networking varies in many ways from virtual machine (VM) or physical machine networking:

•  In some respects, virtual machines are more versatile than physical computers since they can handle networking setups such as NAT and host networking. Docker utilises a bridge network by default, and although it can enable host networking, this feature is only accessible on Linux.
•  When utilising Docker containers, network isolation is done using a network namespace rather than a totally distinct networking stack.
•  The Docker host must be able to handle networking at this scale in order to operate hundreds of containers on a single-node host. As virtual machines generally execute fewer tasks per instance, they seldom exceed these network restrictions.

What Are Network Drivers for Docker?

 Docker manages communication between containers by building a default bridge network, allowing you to concentrate on developing and executing containers rather than networking. This default bridge network is often effective, but it is not your only choice.

 Docker enables the creation of three kinds of network drivers by default: bridge, host, and none. However, they may not be suitable for all use cases, therefore we will also investigate user-defined networks like overlay and macvlan. Examine each one in further detail.

The Bridge Driver

 This is the standard. When Docker is launched, a bridge network is immediately constructed, and all newly launched containers will automatically connect to it.

 This may be used if you need containers operating in isolation to connect and interact with one another. The bridge network overcomes the port conflict issue since containers operate in isolation. Containers operating in the same bridge network are able to interact with one another, and Docker utilises iptables on the host system to prohibit access to the bridge from outside the bridge.

The Host  Driver

 Host drivers, as their name indicates, use the networking offered by the host computer. And it eliminates network separation between the container and the Docker-running host computer. If you run a container that binds to port 80 and utilises host networking, for instance, the container’s application is accessible on port 80 on the host’s IP address. If you do not want to depend on Docker’s networking, you may utilise the network of the host computer. A shortcoming of the host driver is that it is incompatible with Docker desktop; a Linux host is required to utilise it. 

The None Driver

The none network driver connects containers to no network. Containers lack access to the external network and cannot interact with one another. It may be used when a container’s networking needs to be disabled.

Types of Docker Networks

 Docker has network drivers tailored to various use cases. The three most prevalent docker network types are bridge, overlay, and macvlan.

Bridge Networks

 Bridge networking is the most prevalent form of network. It is confined to containers operating on a single Docker-powered host. Bridge networks are simple to establish, administer, and troubleshoot.

Port mapping must be enabled for bridge network containers to communicate or be accessible from the outside world. Consider the possibility of a Docker container running a web service on port 80. Because this container is tied to the bridge network on a private subnet, it is necessary to map a port on the host system, such as 8000, to port 80 on the container for external traffic to access the web service.

 Overlay Networks

 On top of a physical network, an overlay network employs software virtualization to build extra levels of network abstraction. For multi-host network connectivity, Docker utilises an overlay network driver. This driver employs Virtual Extensible Local Area Network (VXLAN) technology, which provides portability across cloud, on-premise, and virtual environments. VXLAN eliminates conventional portability restrictions by extending layer 2 subnets over layer 3 network borders; hence, containers may operate on foreign IP subnets.

Macvlan Networks

 Using layer 2 segmentation, the macvlan driver connects Docker containers directly to the host network interfaces. No port mapping or network address translation (NAT) is required, and containers can be assigned an externally accessible public IP address. Since packets are routed directly from the Docker host network interface controller (NIC) to the containers, macvlan networks have low latency.

Networking with Multiple Docker Hosts

 When dealing with several hosts, advanced Docker orchestration technologies are required to simplify the administration of networking amongst a cluster of servers. Docker Swarm, Kubernetes, and Apache Mesos are well-known orchestration solutions now.

Docker Swarm

Docker Swarm is a native utility developed by Docker Inc. for orchestrating Docker containers. It permits the management of a cluster of hosts as a single pool of resources.

 Docker Swarm uses overlay networks to communicate between hosts. The swarm management service is responsible for allocating IP addresses to containers automatically.

 Each service in the swarm is allocated a unique DNS name for service discovery. In addition, Docker Swarm incorporates a DNS server. Through this integrated DNS server, you may query each container operating inside a swarm.

Kubernetes 

Kubernetes Guide is a method for automating the deployment, scaling, and administration of containerized applications on a single host or across a cluster. Kubernetes handles networking differently from Docker, using native notions like as services and pods. Each pod has an IP address, connecting pods is not necessary, and explicit mapping of container ports to host ports is not required. DNS-based service discovery plugins are available for use in service discovery.

Apache Mesos is an open-source project used to manage a cluster of containers, offering efficient resource sharing and isolation across distributed applications. 

Mesos 

Mesos use an IP address management (IPAM) server and client to control the networking of containers. The IPAM server is responsible for assigning IP addresses on demand, while the IPAM client serves as a link between a network isolator module and the IPAM server. The Mesos agent loads a network isolator module, which is a lightweight module. It examines scheduler task needs and use IPAM and network isolator services to assign IP addresses to containers. Mesos-dns is a DNS-based discovery tool for Mesos services. It enables applications and services running on Mesos to communicate with each other through the DNS service.

DevOps Certification

Training Course

100% Placement Guarantee

View course

Conclusion

Docker containers facilitate the storing and administration of all your images and other processes. It allows you to effectively develop and manage projects. No specialised help is required to use it. Docker has all the vital features necessary to enhance the overall functioning of your firm. It can effectively organise your work and answer any queries or concerns you may have. 

If you are also seeking a means to join this system and want to learn more about Devops, the ideal way to do so is to seek out the finest online platform for Devops training. StarAgile provides numerous courses that assist in getting both practical and academic understanding of all Devops principles. With this certification, you will be able to get hands-on knowledge of Docker’s flexible application environment creation. You will be able to learn from the industry’s most accomplished specialists. So, do not wait any longer and begin your profession immediately.