Why not working request to deployment via service request and via ingress request? - kubernetes

Question

Install minikube version: v1.29.0 on MacOs.
I create API endpoint on flask and build in docker image
FROM debian:latest
COPY . /app
WORKDIR /app
RUN pip3 install --no-cache-dir -r requirements.txt
CMD ["uwsgi", "--socket", "0.0.0.0:5001", "--protocol=http", "-w", "wsgi:app", "--ini", "wsgi.ini"]
after load docker image into minikube
minikube image load drnoreg/devops_blog:0.0.1
check minikube
% minikube image ls
docker.io/drnoreg/devops_blog:0.0.1
create deployment, service and ingress yaml
app.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: devops-blog
spec:
selector:
matchLabels:
run: devops-blog
replicas: 1
template:
metadata:
labels:
run: devops-blog
spec:
containers:
- name: devops-blog
image: docker.io/drnoreg/devops_blog:0.0.1
ports:
- name: pod-port
containerPort: 5001
---
apiVersion: v1
kind: Service
metadata:
name: devops-blog
labels:
run: devops-blog
spec:
type: NodePort
ports:
- name: pod-port
port: 5001
targetPort: 5001
protocol: TCP
nodePort: 30001
selector:
run: devops-blog
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: devops-blog
namespace: devops-blog
spec:
rules:
- host: devops-blog.cluster.local
http:
paths:
- pathType: ImplementationSpecific
backend:
service:
name: devops-blog
port:
number: 5001
execute create namespace
kubectl create namespace devops-blog
set current namespace
kubectl config set-context --current --namespace=devops-blog
and create deployment, service and ingress
kubectl create -f app.yaml
after try forwarding port for check working flask API
kubectl port-forward devops-blog-f666d8cd7-njp95 5001:5001
Forwarding from 127.0.0.1:5001 -> 5001
Forwarding from [::1]:5001 -> 5001
Handling connection for 5001
Handling connection for 5001
flask API service in minikube is working.
% kubectl get service -n devops-blog -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
devops-blog NodePort 10.99.37.126 <none> 5001:30001/TCP 45s run=devops-blog
% kubectl get pod -n devops-blog -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
devops-blog-f666d8cd7-b9n7j 1/1 Running 0 57s 10.244.0.34 minikube <none> <none>
% kubectl get node -n devops-blog -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
minikube Ready control-plane 16h v1.26.1 192.168.49.2 <none> Ubuntu 20.04.5 LTS 5.10.47-linuxkit docker://20.10.23
Now I try to check working API via minikube service
% telnet 192.168.49.2 30001
Trying 192.168.49.2...
not working
add to /etc/hosts
127.0.0.1 devops-blog.cluster.local
try to check working API via ingress minikube
% telnet devops-blog.cluster.local 80
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
not working too.
Why not working request to deployment via service request and via ingress request?
How solve this problem?

Answer 1

In case you did not enable the ingress addon try enable it by executing the following command
$ minikube addons enable ingress
Instead of NodePort service try using the clusterIP service for the app and when you are creating ingress you can give this service as backend like this
service.yaml
apiVersion: v1
kind: Service
metadata:
name: devops-blog
labels:
run: devops-blog
spec:
type: ClusterIP
ports:
- name: pod-port
port: 5001
targetPort: 5001
protocol: TCP
selector:
run: devops-blog
ingres.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: devops-blog
namespace: devops-blog
annotations:
kubernetes.io/ingress.class: "nginx"
nginx.ingress.kubernetes.io/ssl-redirect: "false" #Since you are using localhost
spec:
rules:
- host: devops-blog.cluster.local
http:
paths:
- pathType: ImplementationSpecific
backend:
service:
name: devops-blog
port:
number: 5001
path: /
Once the ingress is generated the IP try opening it in local browser with http://devops-blog.cluster.local/ or curl it like curl $ curl http://devops-blog.cluster.local/.
Note: In case you are deploying this app in the cloud try LoadBalancer as a service.
Try this tutorial as it explained in detail