Kubernetes logs don't print requests output when I use a port in an address - go

Question

I've created a cluster with minikube
minikube start
Applied this yaml manifest:
apiVersion: apps/v1
kind: Deployment
metadata:
name: gateway-deployment
spec:
selector:
matchLabels:
app: gateway
replicas: 1
template:
metadata:
labels:
app: gateway
spec:
containers:
- name: gateway
image: docker_gateway
imagePullPolicy: Never
ports:
- containerPort: 4001
protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
name: gateway
spec:
selector:
app: gateway
ports:
- protocol: TCP
port: 4001
And my GO app in the container docker_gateway is just a gin http server with one route
package main
import "github.com/gin-gonic/gin"
func main() {
r := gin.Default()
r.GET("/hello", func(c *gin.Context) {
c.JSON(200, gin.H{
"message": "hello",
})
})
server = &http.Server{
Addr: ":4001",
Handler: r,
}
server.ListenAndServe()
}
In Postman I make requests to 192.168.252.130:4001/hello and get a responses
But Kubernetes Pod's logs in Kubernetes don't print those requests. I expect to get this:
[GIN] 2019/10/25 - 14:17:20 | 200 | 1.115µs | 192.168.252.1| GET /hello
But an interesting thing is when I add Ingress
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress
spec:
backend:
serviceName: gateway
servicePort: 4001
I am able to make requests to 192.168.252.130/hello and 192.168.252.130:4001/hello
And without the port Pod's logs print requests, but with the port - they don't.
[GIN] 2019/10/25 - 14:19:13 | 200 | 2.433µs | 192.168.252.1| GET /hello

Answer 1

It's because you cannot access a kubernetes service of ClusterIP type from outside(in your case, outside of minikube) of the cluster.
Learn more about service types here
To access your service from outside, change your service to NodePort type.
Something like:
apiVersion: v1
kind: Service
metadata:
name: gateway
spec:
selector:
app: gateway
ports:
- protocol: TCP
nodePort: 30036
port: 4001
type: NodePort
Then you will be able to access it at http://<minikube-ip>:30036/