Basic | Networking and Communication Between Pods in Kubernetes
Kubernetes is a powerful platform for managing containerized applications and services. One of the key components of successful deployment in Kubernetes is ensuring effective networking and communication between pods.
In this blog, we will dive into the details of networking in Kubernetes and how pods communicate with each other.
In Kubernetes, each pod is assigned its own unique IP address and hostname. Pods within the same node can communicate with each other using these IP addresses. Pods in different nodes can communicate with each other through the network overlay created by the cluster network provider.
Kubernetes uses the Container Network Interface (CNI) to manage the network overlay and provide network connectivity between pods. The CNI is a plugin-based architecture, which means that different network providers can be used depending on the needs of the cluster. Some popular CNIs include Calico, Flannel, and Weave Net.
Service and Endpoints
Kubernetes provides an abstraction called Service to expose pods to the network. A Service can be thought of as a logical set of pods that provide specific functionality. Services provide a stable IP address and hostname, which can be used by other pods to communicate with the pods in the Service. The set of pods that make up a Service is defined by a selector in the Service definition. When a new pod is created that matches the selector, it is automatically added to the Service and can be accessed through the Service IP and hostname.
In addition to the Service IP and hostname, Services also have a set of endpoints. Each endpoint corresponds to a pod in the Service and provides its IP address. This allows other pods to communicate directly with the pods in the Service.
Service Discovery
Kubernetes provides several mechanisms for pods to discover the IP addresses and hostnames of other pods and Services in the cluster. The most common method is through environment variables and DNS. When a pod is created, it has access to the environment variables of all Services in the cluster. These environment variables contain the IP address and hostname of the Services. Pods can use these environment variables to communicate with the Services.
In addition, Kubernetes also provides a built-in DNS server that can resolve the hostnames of Services and pods in the cluster. This allows pods to communicate with each other using hostnames instead of IP addresses, making the communication more human-readable and less error-prone.
In Conclusion Networking and communication between pods is a critical aspect of deploying applications in Kubernetes. By using Services, endpoints, and DNS, Kubernetes provides a powerful and flexible way for pods to communicate with each other and expose themselves to the network.
Now we understand a clear picture of how communication is done,…will deep dive further into the next part!
Thanks for reading! I’d appreciate your support and engagement in my stories. :)
Stay informed and entertained by subscribing to my Medium Newsletter. Get my latest articles and content first!
