I am researching different types of loadbalancing methods available through kubernetes .I want to implement & see before deciding on one .I'm stuck at how to actually define typeof-loadbalancer.If it isn't possible through helm can anyone suggest other options please .
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1 Answer
Well there are 2 possibble options.
One is to create a LoadBalancer type for each service you want to be exposed. In case you have just one service that's great. That's rarely the case of course :)
If you build your k8s cluster properly ( having Prometheus-Operator doing the monitoring for example ) most likely besides the business logic service/s, you would want to expose internal cluster valuable services like Grafana.
That's why even if you have just 1 service, for future extension of such type of need the best would be to use an Ingress resource. It providees a way to expose multiple services through a single IP address — HTTP level (network layer 7).
You could play with HTTP headers essentially and do some path/host routing.
You express the definition for your object and helm would do the installation. Another option is to use a tool like ArgoCD, basically sticking to GitOps policy.
A fundamnetal knowledge is to be aware that the Load Balancer/Ingress would forward the traffic to the service, not the pods. Services are abstracted entities by kube-proxy, by default kube-proxy uses a round-robin algorithm.
https://kubernetes.io/docs/concepts/services-networking/service/
Regarding the definition, it follows the standart K8s scheme [ apiVersion, kind, metadata, spec fields]. Example would be an Ingress created from AWS-Ingress-Controller.
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress
namespace: management
annotations:
kubernetes.io/ingress.class: alb
alb.ingress.kubernetes.io/scheme: internet-facing
spec:
rules:
- host: grafana.com
http:
paths:
- backend:
serviceName: grafana
servicePort: 80
path: /*
