Getting CoreDNS to Resolve on Your Raspberry Pi Kubernetes Cluster

Deploying a Kubernetes cluster on Raspberry Pi can be an exciting project, providing a hands-on approach to understanding container orchestration. A common issue that arises during setup is the proper configuration for DNS resolution using CoreDNS. CoreDNS is vital in a Kubernetes cluster as it handles service discoveries through DNS, allowing applications to communicate efficiently.

Prerequisites

Before diving into the configurations, ensure you have the following prerequisites:

• Kubernetes Cluster: Set up on your Raspberry Pi devices. Ensure all nodes are up and connected using softwares like kubeadm, k3s, or microk8s.
• Access: Kubernetes admin access with kubectl configured.
• Network Connectivity: Ensure all Raspberry Pi nodes can communicate with each other.

Understanding CoreDNS in Kubernetes

CoreDNS acts as the DNS server managing name resolution for internal services within the Kubernetes cluster. When properly configured, it resolves service names to their respective IPs, allowing for service-to-service communication.

Deployment Verification

Before troubleshooting or making alterations, verify your CoreDNS deployment. Use:

• Errors & Health: Ensure issues are logged and health checks are in place.
• Kubernetes Block: The section responsible for handling Kubernetes service domain resolutions.
• Forward: In case of unresolvable requests, CoreDNS forwards them according to the specified resolv.conf.