Building a Kubernetes cluster on cost-effective hardware like the Raspberry Pi presents unique challenges for external access and load balancing. A powerful solution involves leveraging the UniFi Dream Machine Pro (UDM Pro) by integrating it with the cluster using BGP (Border Gateway Protocol). This setup allows the cluster itself to dynamically advertise service IP addresses to the router, enabling the UDM Pro to handle traffic distribution and provide a robust, self-healing ingress mechanism without external load balancers.
Creating a Kubernetes cluster using Raspberry Pi boards has become incredibly popular, offering an accessible way to learn and experiment with container orchestration on affordable hardware. While setting up the cluster nodes is straightforward, providing external access to deployed applications and ensuring effective load balancing can be a stumbling block.
A highly effective strategy to overcome this involves integrating the cluster with your network gateway, specifically leveraging the capabilities of a UniFi Dream Machine Pro (UDM Pro). By utilizing BGP (Border Gateway Protocol), you can transform the UDM Pro from just a router into an intelligent partner for your cluster’s networking.
Here’s how it works: within the Kubernetes cluster, a component (often something like MetalLB in BGP mode) is deployed. This component peers with the UDM Pro using BGP. When a service of type LoadBalancer is created in Kubernetes, instead of waiting for a cloud provider to assign an IP, the cluster component advertises the service’s IP address directly to the UDM Pro via BGP.
The UDM Pro then learns the best path to reach that specific service IP address, which is one of the cluster nodes. If multiple nodes can host the service, BGP automatically handles the distribution of incoming connections across those available paths, providing inherent load balancing. Furthermore, if a node fails, BGP routes are withdrawn or updated, allowing the UDM Pro to automatically direct traffic only to healthy nodes, ensuring high availability and resilience.
This sophisticated integration provides a seamless and dynamic ingress solution for your Raspberry Pi Kubernetes cluster. It eliminates the need for potentially complex or costly external load balancers and fully utilizes the enterprise-grade routing features available in the UDM Pro. The result is a powerful, flexible, and cost-efficient home lab or small-scale production setup that handles traffic distribution and failover with impressive capability, showcasing how readily available hardware can be combined with advanced networking protocols for a truly robust infrastructure.
Source: https://itnext.io/kubernetes-on-raspberry-pi-and-bgp-load-balancing-with-unifi-dream-machine-pro-d5b94b6cfe99?source=rss—-5b301f10ddcd—4
