Kubernates Nginx-Ingress rule not working - kubernetes

Question

I installed the ingress controller using the following command:
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.5.1/deploy/static/provider/cloud/deploy.yaml
And the result of kubectl get pods --namespace=ingress-nginx is:
NAME READY STATUS RESTARTS AGE
ingress-nginx-admission-create-x4mss 0/1 Completed 0 28m
ingress-nginx-admission-patch-jn9cz 0/1 Completed 1 28m
ingress-nginx-controller-8574b6d7c9-k4jbj 1/1 Running 0 28m
For kubectl get service ingress-nginx-controller --namespace=ingress-nginx I get:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx-controller LoadBalancer 10.106.134.128 localhost 80:32294/TCP,443:30997/TCP 30m
As for my deployment and service I have the following:
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: app
name: app
namespace: namespace
spec:
replicas: 1
selector:
matchLabels:
app: app
template:
labels:
app: app
spec:
containers:
- image: image
name: app
ports:
- containerPort: 5000
restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
name: app-service
namespace: namespace
spec:
type: ClusterIP
selector:
app: app
ports:
- name: app-service
port: 5000
targetPort: 5000
My Ingress is as follows:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress
namespace: namespace
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
ingressClassName: nginx
rules:
- host: com.host.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: app-service
port:
number: 5000
My pod and service are both running fine.
The result of running kubectl describe pod command is:
Name: app-6b9f7fc47b-sh6nc
Namespace: namespace
Priority: 0
Service Account: default
Node: docker-desktop/192.168.65.4
Start Time: Wed, 30 Nov 2022 16:22:04 -0500
Labels: app=app
pod-template-hash=6b9f7fc47b
Status: Running
IP: 10.1.0.237
IPs:
IP: 10.1.0.237
Controlled By: ReplicaSet/app-6b9f7fc47b
Containers:
app:
Container ID: docker://ba77235d044c24b0f1391c56a2e8653a598a5c130ea4d15ff3b41cd96659fd4a
Image: image
Image ID: docker://sha256:912cb58ab1c3f2dd628c0b7db4d7f9ac6df4efbe4fcb86979b6a84614db8a675
Port: 5000/TCP
Host Port: 0/TCP
State: Running
Started: Wed, 30 Nov 2022 16:22:05 -0500
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-8pmjz (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kube-api-access-8pmjz:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 29m default-scheduler Successfully assigned namespace/app-6b9f7fc47b-sh6nc to docker-desktop
Normal Pulled 29m kubelet Container image "image" already present on machine
Normal Created 29m kubelet Created container app
Normal Started 29m kubelet Started container app
Running the following command kubectl get ingress --all-namespaces yields:
NAMESPACE NAME CLASS HOSTS ADDRESS PORTS AGE
namespace ingress nginx com.host.com 80 7s
I have tried using different ports, changing the controller, using a load balance type instead of cluster ip and yet nothing works when it comes to trying to make the ingress rule work. I have set the ingress-controller external ip as com.host.com in my hosts file as well. Furthermore, I am using docker-desktop as my node, however, I'm having this issue on minikube as well. Any help is appreciated.

Answer 1

Your container's containerPort is 3000 while your service targetPort is 5000. Make sure that your service' targetPort, your container's containerPort and last but not least the listening port of your app are all the same.
Update:
So I guess it turned out that the problem is with name resolution.
com.host.com is not resolvable on your machine.
Using the localhost or 127.0.0.1 didn't match the host from the ingress rule -> that's why the default 404 handler was chosen.
So either fix name resolution or remove the host from the ingress rule.

Answer 2

Bear in mind that the ingress controller will only update the IP of the ingress if the mapped service is up and ready. Your ingress shows that it's using app-service on port 5000 as its backend service, but your question does not show a listing of the pods on the namespace namespace where it appears your application pods are. Please could you add that to the question -- it is possible that either your pods aren't coming up successfully, or they're listening on a different port to 5000
UPDATE
Please also try the following:
You're specifying that the container uses port 5000. But is it actually using 5000? try:
kubectl exec -it -n namespace app-6b9f7fc47b-sh6nc -- bash (or sh depending on what the default shell is for your app)
and then try curl localhost:5000 to see if it responds.
Check the ingress controller logs:
kubectl logs -f -n ingress-nginx and see if there's any log messages that might help you identify what's going on.