Metallb can be used in Static (Bare Metal) clusters when you can’t order a load balancer from a cloud provider. Metallb can work in L2 or BGP modes. Below is an example of Metallb usage in L2 mode.
We will create an Ingress Controller with LoadBalancer inlet. And we will also expose standalone Nginx using a Service with the LoadBalancer type.
First, you have to decide which NodeGroups will be used to deploy applications that have to be exposed by the LoadBalancer service.
Ingress controllers run on frontend nodes, and Nginx runs on a worker node in this example. They have common label node-role/metallb="".
apiVersion: deckhouse.io/v1
kind: NodeGroup
metadata:
name: frontend
spec:
disruptions:
approvalMode: Manual
nodeTemplate:
labels:
node-role.deckhouse.io/frontend: ""
node-role/metallb: ""
taints:
- effect: NoExecute
key: dedicated.deckhouse.io
value: frontend
nodeType: Static
---
apiVersion: deckhouse.io/v1
kind: NodeGroup
metadata:
name: worker
spec:
disruptions:
approvalMode: Manual
nodeTemplate:
labels:
node-role/metallb: ""
nodeType: Static
Check that nodes have the correct labels.
kubectl get nodes -l node-role/metallb
NAME STATUS ROLES AGE VERSION
demo-frontend-0 Ready frontend 61d v1.21.14
demo-frontend-1 Ready frontend 61d v1.21.14
demo-worker-0 Ready worker 61d v1.21.14
Module metallb is disabled by default, so you have to explicitly enable it. You also have to set the correct nodeSelector and tolerations for Metallb speakers.
An example of the module configuration:
apiVersion: deckhouse.io/v1alpha1
kind: ModuleConfig
metadata:
name: metallb
spec:
version: 1
enabled: true
settings:
addressPools:
- addresses:
- 192.168.199.100-192.168.199.102
name: frontend-pool
protocol: layer2
speaker:
nodeSelector:
node-role/metallb: ""
tolerations:
- effect: NoExecute
key: dedicated.deckhouse.io
operator: Equal
value: frontend
Create IngressNginxController.
apiVersion: deckhouse.io/v1
kind: IngressNginxController
metadata:
name: main
spec:
ingressClass: nginx
inlet: LoadBalancer
nodeSelector:
node-role.deckhouse.io/frontend: ""
tolerations:
- effect: NoExecute
key: dedicated.deckhouse.io
value: frontend
Check that service with the type LoadBalancer is created in the namespace d8-ingress-nginx.
kubectl -n d8-ingress-nginx get svc main-load-balancer
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
main-load-balancer LoadBalancer 10.222.255.194 192.168.199.100 80:30236/TCP,443:32292/TCP 30s
Your Ingress controller is accessible on an external IP address.
curl -s -o /dev/null -w "%{http_code}" 192.168.199.100
404
Expose your standalone Nginx on 8080 port.
kubectl create deploy nginx --image=nginx
kubectl create svc loadbalancer nginx --tcp=8080:80
Check service.
kubectl get svc nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx LoadBalancer 10.222.9.190 192.168.199.101 8080:31689/TCP 3m11s
Now you can access the application using curl.
curl -s -o /dev/null -w "%{http_code}" 192.168.199.101:8080
200