Load Balancing & Traffic Management

I’m going to be using metallb for loadbalancing my between my master and worker nodes.

Purpose: MetalLB acts as a software-based LoadBalancer for your bare-metal Kubernetes cluster since K3s (or any Kubernetes cluster without a cloud provider) but lacks built-in load balancing for external services.

Why I Need MetalLB:

• ✔ Assigns external IPs to Kubernetes LoadBalancer services.
• ✔ Distributes traffic directly to pods or services across nodes.
• ✔ Enables exposing applications externally (e.g., Prometheus, Grafana, ArgoCD).
• ✔ Supports Layer 2 (ARP-based) or BGP (Border Gateway Protocol) for network traffic handling.

Example Use Cases I will be implementing:

• ✅ Load balancing external traffic to Prometheus, Grafana, ArgoCD.
• ✅ Exposing internal services that don’t need routing logic (e.g., a direct LoadBalancer service).

MetalLB hooks into your Kubernetes cluster, and provides a network load-balancer implementation. In short, it allows you to create Kubernetes services of type LoadBalancer in clusters that don’t run on a cloud provider, and thus cannot simply hook into paid products to provide load balancers.

It has two features that work together to provide this service: address allocation, and external announcement.

More to read up on Metallb here: Metallb Official Doc

For Ingress we are going with NGINX Ingress Controller (For Routing & Security)

Purpose: An Ingress Controller manages HTTP/HTTPS traffic, acting as a reverse proxy to route requests to different Kubernetes services based on domain names and paths.

Why I Need NGINX Ingress:

• ✔ Routes traffic based on domain names (e.g., grafana.homelab.local → Grafana, prometheus.homelab.local → Prometheus).
• ✔ Secures access with TLS (Let’s Encrypt, Cloudflare SSL, etc.).
• ✔ Enables authentication (OAuth, Basic Auth, etc.).
• ✔ Consolidates multiple services behind a single external IP.
• ✔ Works well with ArgoCD & GitOps setups.

Example Use Cases for me:

• ✅ Hosting multiple web apps on the same external IP with different subdomains.
• ✅ Using Cloudflare proxy & TLS for security.
• ✅ Implementing OAuth authentication for Grafana, ArgoCD, etc.

How They Work Together

• MetalLB assigns an external IP to the NGINX Ingress Controller (as a LoadBalancer service).
• NGINX Ingress Controller then routes traffic to different Kubernetes services based on domain names or paths.
• This setup allows secure & efficient routing while ensuring that services are load-balanced.