Kubenetes Load Balancer is not accessible

Question

I am trying to host the below (deployment frontend) Kubernetes deployment in the AWS EKS cluster, after deploying deployment and created service and ingress, everything gets successfully deployed and created but when i try to access the Load Balancer DNS from outside then this LoadBalancer is not accessible. Can someone please point the reason?

**Below code (deployment-2048) is working and Load Balancer is accessible but not in the case of (deployment frontend) **.

apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2021-03-09T14:08:45Z"
  generation: 2
  name: frontend
  namespace: default
  resourceVersion: "2864"
  uid: a7682f3b-dffa-498f-be47-b231cce0720a
spec:
  minReadySeconds: 20
  progressDeadlineSeconds: 600
  replicas: 4
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: webapp
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        name: webapp
    spec:
      containers:
      - image: kodekloud/webapp-color:v2
        imagePullPolicy: IfNotPresent
        name: simple-webapp
        ports:
        - containerPort: 80
          protocol: TCP
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 4
  observedGeneration: 2
  readyReplicas: 4
  replicas: 4
  updatedReplicas: 4

---
apiVersion: v1
kind: Service
metadata:
  namespace: default
  name: service-1
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  type: LoadBalancer
  selector:
    name: webapp
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  namespace: default
  name: ingress-1
  annotations:
    kubernetes.io/ingress.class: alb
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/target-type: ip
spec:
  rules:
    - http:
        paths:
          - path: /*
            backend:
              serviceName: service-1
              servicePort: 80

---
apiVersion: v1
kind: Namespace
metadata:
  name: game-2048
---
apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: game-2048
  name: deployment-2048
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: app-2048
  replicas: 5
  template:
    metadata:
      labels:
        app.kubernetes.io/name: app-2048
    spec:
      containers:
      - image: alexwhen/docker-2048
        imagePullPolicy: Always
        name: app-2048
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  namespace: game-2048
  name: service-2048
spec:
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  type: LoadBalancer
  selector:
    app.kubernetes.io/name: app-2048
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  namespace: game-2048
  name: ingress-2048
  annotations:
    kubernetes.io/ingress.class: alb
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/target-type: ip
spec:
  rules:
    - http:
        paths:
          - path: /*
            backend:
              serviceName: service-2048
              servicePort: 80

Do you want to access the `LB` from inside the cluster? Or you mean externally? EDIT - ok, I missed the `from outside`. So by accessing the `LB` externally you must first expose it to the outside world. Maybe this will help [AWS Docs](https://aws.amazon.com/premiumsupport/knowledge-center/eks-kubernetes-services-cluster/) — Aris, Mar 10 '21 at 08:58
In addition to the above comment, check the `Create a LoadBalancer service` from the docs I commented before. — Aris, Mar 10 '21 at 09:06
@Aristotle Thanks for the comment. Do see if there is any difference in above two codes, LB in one is accessible and not in another — user190245, Mar 10 '21 at 09:19
The only difference is the selector name :/ `app.kubernetes.io/` — Aris, Mar 10 '21 at 11:05
Could you check with different image? Below one answer you mention you've changed `containerPort` to 80 from 8080, could you also change in question? What error you have 404, 502? You are curling it or checking via browser? On what port your container is listening (netstat -plnt) ? — PjoterS, Mar 10 '21 at 12:22
For the service, try with type:NodePort instead of type:LoadBalancer. — herbertgoto, Mar 10 '21 at 13:09
@PjoterS i am accessing it via browser, just updated with Browser error — user190245, Mar 10 '21 at 13:25
From your output it looks like your frontend is exposed on port 8080. What if you will set service to `targetPort: 8080` and deployment `containerPort: 8080`. You dont have any strange firewall rules which could block 80 or 8080? For test purpose, could you use in your frontend image from 2048 `alexwhen/docker-2048`? It might be related with image — PjoterS, Mar 10 '21 at 13:59
@PjoterS, this got worked. When i kept only containerPort and TargetPort to 8080. and the others to 80. Why it worked like this. — user190245, Mar 10 '21 at 14:29
Thanks All, for helping this worked. Do we have somewhere we can see if port conflict can be seen. — user190245, Mar 10 '21 at 14:32

score 2 · Accepted Answer · answered Mar 10 '21 at 16:18

In your original question (without edits and additional information), in frontend deployment you have port values misconfigured.

Port exposes the Kubernetes service on the specified port within the cluster. Other pods within the cluster can communicate with this server on the specified port.
TargetPort is the port on which the service will send requests to, that your pod will be listening on. Your application in the container will need to be listening on this port also.
ContainerPort defines the port on which app can be reached out inside the container.

In short story, containerPort from deployment must have the same value as targetPort in Service.

User @herbertgoto had good idea, but unfortunately didn't specify exactly what should be done. When you have changed containerPort from 8080 to 80 it should work but I guess there was issue with repopulating this change in all resources (recreate ingress resource, redeploying pod).

One of the first troubleshooting steps should be to check if your container is listening on the proper port. That's why I requested to $ netstat output.

Useful command to check is to use $ kubectl get ep to check service endpoints.

Note

If you will skip targetPort in service and have only port, Kubernetes automatically assign targetPort value based on port.

When i kept only containerPort and TargetPort to 8080. and the others to 80. Why it worked like this.

Default port port for service is 80. So when you create service with port 80, you don't need to specify any additional things. When you have set port in service to 8080 you also need to specify it.

I've created service with port 8080 no my GKE cluster.

$ kubectl get svc
NAME         TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)          AGE
kubernetes   ClusterIP      10.104.0.1      <none>          443/TCP          153m
my-nginx     LoadBalancer   10.104.14.137   34.91.230.207   8080:31311/TCP   9m39s
$ curl 34.91.230.207
curl: (7) Failed to connect to 34.91.230.207 port 80: Connection timed out
$ curl 34.91.230.207:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
...

Responses from Browser:

Only externalIP ExternalIP:8080 As you see I needed to specify port 8080 in browser and curl command when I didn't use default 80 port.

Conclusions:

Deployment containerPort and Service targetPort must have the same value. When you are using service with port different than 80 you need to specify it by adding :<portNubmer>. That's why in almost all guides in the internet yo can see service port with value 80.

Thanks a lot , For explaining in detail. Your explanation gives the right direction. — user190245, Mar 10 '21 at 17:33

score -1 · Answer 2 · answered Mar 09 '21 at 22:52

-1

containerPort is set to 8080 and service targetPort is 80

answered Mar 09 '21 at 22:52

herbertgoto

339
1
5

still same issue. i change the port from 8080 to 80 – user190245 Mar 10 '21 at 07:30
For the service, try with type:NodePort instead of type:LoadBalancer. – herbertgoto Mar 10 '21 at 13:10
i had tried NodePort, it did not work so i changed to LB, so it worked in one and not in other – user190245 Mar 10 '21 at 13:58
Good idea (upvoting) but you should elaborate your answer and avoid providing one line answer. – PjoterS Mar 10 '21 at 16:20

Kubenetes Load Balancer is not accessible

2 Answers2

Conclusions: