How to keep LoadBalancer[ALB] even after we delete Ingress Manifest in AWS EKS? - amazon-web-services

Question

When we launch the EKS Cluster using the below manifest, it is creating ALB. We have a default ALB that we are using, let's call it EKS-ALB. The Hosted zone is routing traffic to this EKS-ALB. We gave tag ingress.k8s.aws/resource:LoadBalancer, ingress.k8s.aws/stack:test-alb, elbv2.k8s.aws/cluster: EKS. But when we delete the manifest, it is deleting the default ALB and we need to reconfigure hosted zone again with New ALB which will get created in next deployment. Is there any way to block Ingress-controller not deleting ALB, but only deleting the listeners and Target Group?
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: test-nginx-rule
namespace: test
annotations:
alb.ingress.kubernetes.io/group.name: test-alb
alb.ingress.kubernetes.io/scheme: internal
alb.ingress.kubernetes.io/target-type: instance
alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}, {"HTTPS": 443}]'
alb.ingress.kubernetes.io/ssl-redirect: '443'
alb.ingress.kubernetes.io/healthcheck-port: traffic-port
alb.ingress.kubernetes.io/healthcheck-path: /index.html
alb.ingress.kubernetes.io/success-codes: 200-399
alb.ingress.kubernetes.io/security-groups: eks-test-alb-sg
spec:
ingressClassName: alb
rules:
- host: test.eks.abc.com
http:
paths:
- pathType: Prefix
path: "/"
backend:
service:
name: test-svc
port:
number: 5005
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: test-dep
namespace: test
labels:
app: test
spec:
replicas: 1
restartPolicy:
selector:
matchLabels:
app: test
template:
metadata:
labels:
app: test
spec:
containers:
- name: test
image: Imagepath
imagePullPolicy: IfNotPresent
ports:
- containerPort: 5005
resources:
requests:
memory: "256Mi"
cpu: "500m"
---
apiVersion: v1
kind: Service
metadata:
name: test-svc
namespace: test
labels:
app: test
spec:
type: NodePort
ports:
- port: 5005
targetPort: 80
protocol: TCP
selector:
app: test
---
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
name: test-scaler
namespace: test
spec:
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: test-dep
minReplicas: 1
maxReplicas: 5
targetCPUUtilizationPercentage: 60
---

Answer 1

In order to achieve the existing ALB not being deleted with group.name annotation enabled, we need to meet following conditions:
ALB should be tagged with below 3 tags:
alb.ingress.kubernetes.io/group.name: test-alb
alb.ingress.kubernetes.io/scheme: internal
alb.ingress.kubernetes.io/target-type: instance
Create a dummy ingress with the same group name with the below manifest.
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: test-nginx-rule
namespace: test
annotations:
alb.ingress.kubernetes.io/group.name: test-alb
alb.ingress.kubernetes.io/scheme: internal
alb.ingress.kubernetes.io/target-type: instance
alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}, {"HTTPS": 443}]'
alb.ingress.kubernetes.io/ssl-redirect: '443'
alb.ingress.kubernetes.io/healthcheck-port: traffic-port
alb.ingress.kubernetes.io/healthcheck-path: /index.html
alb.ingress.kubernetes.io/success-codes: 200-399
alb.ingress.kubernetes.io/security-groups: eks-test-alb-sg
spec:
ingressClassName: alb
rules:
- host: dummy.eks.abc.com
http:
paths:
- pathType: Prefix
path: "/"
backend:
service:
name: test-svc
port:
number: 5005
After deploying the above manifest, an ingress will be created using the same ALB and listener will have rule of if host is dummy.eks.abc.com, it will return 443. It's create and forget type of manifest, so after creating this ingress, even after we delete all the running deployment services (except the dummy manifest file above), the ALB will remain.