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I am following a tutorial to set Kubernetes with an ingress managed service. The cluster is,

  • 1 controller
  • 2 worker Kubernetes cluster
  • kubeadm built
  • running Kubernetes v1.25.3 (latest at the time of writing)
  • running weave-net
  • running ingress-nginx
  • EC2, not EKS

I am just expecting to see the nginx default page when I access the AWS Application Load Balancer, ALB, DNS name - nothing fancy.

I first used this helm chart to deploy nginx-ingress, as per the "Quick start" docs.

helm upgrade --install ingress-nginx ingress-nginx \
  --repo https://kubernetes.github.io/ingress-nginx \
  --namespace ingress-nginx --create-namespace

I then deployed the following in the default namespace.

ingress.yaml

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-app-ingress
  namespace: default
spec:
  ingressClassName: nginx
  rules:
  - host: ***alb***.elb.amazonaws.com
    http:
      paths:
      - backend:
          service:
            name: nginx-service
            port:
              number: 8080
        path: /
        pathType: Exact

service.yaml

---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  labels:
    app: nginx
    svc: test-nginx
spec:
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 8080
      targetPort: 80

deployment.yaml

---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  labels:
    app: nginx
    svc: test-nginx
spec:
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 8080
      targetPort: 80

k get svc -A
NAMESPACE       NAME                                 TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
default         demo                                 ClusterIP      *****            <none>        80/TCP                       7h53m
default         kubernetes                           ClusterIP      *****            <none>        443/TCP                      2d6h
default         nginx-service                        ClusterIP      *****            <none>        8080/TCP                     26h
ingress-nginx   ingress-nginx-controller             LoadBalancer   *****            <pending>     80:32573/TCP,443:32512/TCP   35h
ingress-nginx   ingress-nginx-controller-admission   ClusterIP      *****            <none>        443/TCP                      35h
kube-system     kube-dns                             ClusterIP      *****            <none>        53/UDP,53/TCP,9153/TCP       2d6h

Two AWS security groups are in effect, one for the controller and one for the workers. Both these security groups have ports 6783 - 6784 open as required by ingress-nginx.

The ALB is set with the following.

  • same Availability Zones as the worker nodes
  • default (open) security group
  • Listener protocol:port = HTTP:80
  • same VPC as the EC2 instances.
  • Scheme = internet-facing
  • IP address type = ipv4

The target group for this ALB is set as follows.

  • both worker nodes
  • Protocol : Port = HTTP: 32573
  • Protocol version = HTTP1
  • same VPC as the EC2 instances.
  • Health path = /

On the assumption that the target group would block traffic to "unhealthy" nodes, I previously deployed a separate service directly on a different NodePort, rather than via Ingress, to fudge the health check to Healthy, but this made no difference.

I have,

  • double checked that I have followed the steps in the tutorial exactly
  • looked through the logs but cannot find anything that would suggest an error.
  • terminated all the pods.
  • restarted the nodes.

When I run

k logs ingress-nginx-controller-***** -n ingress-nginx

It returns

-------------------------------------------------------------------------------
NGINX Ingress controller
  Release:       v1.4.0
  Build:         50be2bf95fd1ef480420e2aa1d6c5c7c138c95ea
  Repository:    https://github.com/kubernetes/ingress-nginx
  nginx version: nginx/1.19.10

-------------------------------------------------------------------------------

W1021 13:49:00.607448       7 client_config.go:617] Neither --kubeconfig nor --master was specified.  Using the inClusterConfig.  This might not work.
I1021 13:49:00.607678       7 main.go:209] "Creating API client" host="https://10.96.0.1:443"
I1021 13:49:00.613511       7 main.go:253] "Running in Kubernetes cluster" major="1" minor="25" git="v1.25.3" state="clean" commit="434bfd82814af038ad94d62ebe59b133fcb50506" platform="linux/amd64"
I1021 13:49:00.776507       7 main.go:104] "SSL fake certificate created" file="/etc/ingress-controller/ssl/default-fake-certificate.pem"
I1021 13:49:00.788407       7 ssl.go:533] "loading tls certificate" path="/usr/local/certificates/cert" key="/usr/local/certificates/key"
I1021 13:49:00.807812       7 nginx.go:260] "Starting NGINX Ingress controller"
I1021 13:49:00.820423       7 event.go:285] Event(v1.ObjectReference{Kind:"ConfigMap", Namespace:"ingress-nginx", Name:"ingress-nginx-controller", UID:"f4d537f7-2b89-4fe5-a9ed-c064533b08a2", APIVersion:"v1", ResourceVersion:"96138", FieldPath:""}): type: 'Normal' reason: 'CREATE' ConfigMap ingress-nginx/ingress-nginx-controller
I1021 13:49:01.910567       7 store.go:430] "Found valid IngressClass" ingress="default/my-app-ingress" ingressclass="nginx"
I1021 13:49:01.910942       7 event.go:285] Event(v1.ObjectReference{Kind:"Ingress", Namespace:"default", Name:"my-app-ingress", UID:"9111168a-9dc8-4cf8-a0f6-fe871c3ada61", APIVersion:"networking.k8s.io/v1", ResourceVersion:"245885", FieldPath:""}): type: 'Normal' reason: 'Sync' Scheduled for sync
I1021 13:49:02.009443       7 nginx.go:303] "Starting NGINX process"
I1021 13:49:02.009750       7 leaderelection.go:248] attempting to acquire leader lease ingress-nginx/ingress-controller-leader...
I1021 13:49:02.010156       7 nginx.go:323] "Starting validation webhook" address=":8443" certPath="/usr/local/certificates/cert" keyPath="/usr/local/certificates/key"
I1021 13:49:02.010553       7 controller.go:168] "Configuration changes detected, backend reload required"
I1021 13:49:02.015673       7 status.go:84] "New leader elected" identity="ingress-nginx-controller-567c84f6f-8s5zv"
I1021 13:49:02.081076       7 controller.go:185] "Backend successfully reloaded"
I1021 13:49:02.081398       7 controller.go:196] "Initial sync, sleeping for 1 second"
I1021 13:49:02.081913       7 event.go:285] Event(v1.ObjectReference{Kind:"Pod", Namespace:"ingress-nginx", Name:"ingress-nginx-controller-567c84f6f-52k47", UID:"fa2b26ad-0594-4e43-927a-11a9def12467", APIVersion:"v1", ResourceVersion:"249556", FieldPath:""}): type: 'Normal' reason: 'RELOAD' NGINX reload triggered due to a change in configuration
I1021 13:49:43.652768       7 leaderelection.go:258] successfully acquired lease ingress-nginx/ingress-controller-leader
I1021 13:49:43.652910       7 status.go:84] "New leader elected" identity="ingress-nginx-controller-567c84f6f-52k47"
W1021 14:22:31.247404       7 controller.go:1112] Service "default/demo" does not have any active Endpoint.
I1021 14:22:31.283535       7 admission.go:149] processed ingress via admission controller {testedIngressLength:2 testedIngressTime:0.036s renderingIngressLength:2 renderingIngressTime:0s admissionTime:25.8kBs testedConfigurationSize:0.036}
I1021 14:22:31.283727       7 main.go:100] "successfully validated configuration, accepting" ingress="default/demo"
I1021 14:22:31.289380       7 store.go:430] "Found valid IngressClass" ingress="default/demo" ingressclass="nginx"
I1021 14:22:31.289790       7 event.go:285] Event(v1.ObjectReference{Kind:"Ingress", Namespace:"default", Name:"demo", UID:"50962ac3-d7f1-45bc-8e73-7baf6337331b", APIVersion:"networking.k8s.io/v1", ResourceVersion:"252977", FieldPath:""}): type: 'Normal' reason: 'Sync' Scheduled for sync
W1021 14:22:31.290058       7 controller.go:1112] Service "default/demo" does not have any active Endpoint.
I1021 14:22:31.290210       7 controller.go:168] "Configuration changes detected, backend reload required"
I1021 14:22:31.366582       7 controller.go:185] "Backend successfully reloaded"
I1021 14:22:31.367273       7 event.go:285] Event(v1.ObjectReference{Kind:"Pod", Namespace:"ingress-nginx", Name:"ingress-nginx-controller-567c84f6f-52k47", UID:"fa2b26ad-0594-4e43-927a-11a9def12467", APIVersion:"v1", ResourceVersion:"249556", FieldPath:""}): type: 'Normal' reason: 'RELOAD' NGINX reload triggered due to a change in configuration
I1021 14:25:34.757766       7 controller.go:168] "Configuration changes detected, backend reload required"
I1021 14:25:34.827908       7 controller.go:185] "Backend successfully reloaded"
I1021 14:25:34.828291       7 event.go:285] Event(v1.ObjectReference{Kind:"Pod", Namespace:"ingress-nginx", Name:"ingress-nginx-controller-567c84f6f-52k47", UID:"fa2b26ad-0594-4e43-927a-11a9def12467", APIVersion:"v1", ResourceVersion:"249556", FieldPath:""}): type: 'Normal' reason: 'RELOAD' NGINX reload triggered due to a change in configuration
I1021 14:25:41.191636       7 admission.go:149] processed ingress via admission controller {testedIngressLength:1 testedIngressTime:0.036s renderingIngressLength:1 renderingIngressTime:0s admissionTime:22.1kBs testedConfigurationSize:0.036}
I1021 14:25:41.191800       7 main.go:100] "successfully validated configuration, accepting" ingress="default/my-app-ingress"
I1021 14:25:41.195876       7 event.go:285] Event(v1.ObjectReference{Kind:"Ingress", Namespace:"default", Name:"my-app-ingress", UID:"9111168a-9dc8-4cf8-a0f6-fe871c3ada61", APIVersion:"networking.k8s.io/v1", ResourceVersion:"253276", FieldPath:""}): type: 'Normal' reason: 'Sync' Scheduled for sync
I1021 20:40:45.084934       7 admission.go:149] processed ingress via admission controller {testedIngressLength:1 testedIngressTime:0.049s renderingIngressLength:1 renderingIngressTime:0s admissionTime:22.1kBs testedConfigurationSize:0.049}
I1021 20:40:45.085124       7 main.go:100] "successfully validated configuration, accepting" ingress="default/my-app-ingress"
I1021 20:40:45.088698       7 controller.go:168] "Configuration changes detected, backend reload required"
I1021 20:40:45.088779       7 event.go:285] Event(v1.ObjectReference{Kind:"Ingress", Namespace:"default", Name:"my-app-ingress", UID:"9111168a-9dc8-4cf8-a0f6-fe871c3ada61", APIVersion:"networking.k8s.io/v1", ResourceVersion:"287850", FieldPath:""}): type: 'Normal' reason: 'Sync' Scheduled for sync
I1021 20:40:45.183140       7 controller.go:185] "Backend successfully reloaded"
I1021 20:40:45.184054       7 event.go:285] Event(v1.ObjectReference{Kind:"Pod", Namespace:"ingress-nginx", Name:"ingress-nginx-controller-567c84f6f-52k47", UID:"fa2b26ad-0594-4e43-927a-11a9def12467", APIVersion:"v1", ResourceVersion:"249556", FieldPath:""}): type: 'Normal' reason: 'RELOAD' NGINX reload triggered due to a change in configuration

I notice that the following appears in the logs for the weave-net pods.

k logs weave-net-*w1* -n kube-system

Where *w1* is the pod running on worker node1.

INFO: 2022/10/21 13:49:27.195158 ->[*controller*:6783] error during connection attempt: dial tcp :0->*controller*:6783: connect: connection refused

Where *controller* is the IP address of the control node.

After all of the above, when I navigate to the ALB DNS address, I just get,

internal error - server connection terminated

This is clearly a PEBKAC, but what am I missing?

2
  • There’s a lot of open steps in this question. Have you verified that new pods in the cluster can access the nginx-service.default:8080 and the alb, and are you running external-dns?
    – benjimin
    Nov 29, 2022 at 5:08
  • If you have an ALB why not use alb ingress controller instead of involving nginx controller?
    – benjimin
    Dec 27, 2022 at 18:21

2 Answers 2

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The load balancer will connect to the default security group by default. This security group has a source of itself, which basically means that it blocks everything.

Add the inbound rule of all traffic from "Anywhere-IPv4" to ensure that all traffic can access the load balancer.

0

Check Security Groups again. Ensure, that SG used for Kubernetes service is open for your ALB SG (the best practice clearly said, you shouldn't use defasults, please, create a new one).

ALB must have Target Group. Check events for this TG, you will see the messages, you should see errors if any.

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