minikube - how to access pod via pod ip using curl - kubernetes

Question

I use minikube to create local kubernetes cluster.
I create ReplicationController via webapp-rc.yaml file.
apiVersion: v1
kind: ReplicationController
metadata:
name: webapp
spec:
replicas: 2
template:
metadata:
name: webapp
labels:
app: webapp
spec:
containers:
- name: webapp
image: tomcat
ports:
- containerPort: 8080
and, I print the pods' ip to stdout:
kubectl get pods -l app=webapp -o yaml | grep podIP
podIP: 172.17.0.18
podIP: 172.17.0.1
and, I want to access pod using curl
curl 172.17.0.18:8080
But, the stdout give me: curl: (52) Empty reply from server
I know I can access my application in docker container in pod via service.
I find this code in a book. But the book does not give the context for executing this code.
Using minikube, how to access pod via pod ip using curl in host machine?
update 1
I find a way using kubectl proxy:
➜ ~ kubectl proxy
Starting to serve on 127.0.0.1:8001
and then I can access pod via curl like this:
curl http://localhost:8001/api/v1/namespaces/default/pods/webapp-jkdwz/proxy/
webapp-jkdwz can be found by command kubectl get pods -l app=webapp
update 2
minikube ssh - log into minikube VM
and then, I can use curl <podIP>:<podPort>, for my case is curl 172.17.0.18:8080

Answer 1

First of all, tomcat image expose port 8080 not 80, so the correct YAML would be:
apiVersion: v1
kind: ReplicationController
metadata:
name: webapp
spec:
replicas: 2
template:
metadata:
name: webapp
labels:
app: webapp
spec:
containers:
- name: webapp
image: tomcat
ports:
- containerPort: 8080
minikube is executed inside a virtual machine, so the curl 172.17.0.18:8080 would only work from inside that virtual machine.
You can always create a service to expose your apps:
kubectl expose rc webapp --type=NodePort
And use the following command to get the URL:
minikube service webapp --url
If you need to query a specific pod, use port forwarding:
kubectl port-forward <POD NAME> 8080
Or just ssh into minikube's virtual machine and query from there.

Answer 2

That command is correct, but it only works from a machine that has access to the overlay network. (In case of minikube the host machine does not have that by default).
You can set up a proxy to your pod with:
kubectl port-forward [name of your pod] [pod port]
Thereafter you can (from another shell):
curl 127.0.0.1:port/path
See also: https://kubernetes.io/docs/tasks/access-application-cluster/port-forward-access-application-cluster/#forward-a-local-port-to-a-port-on-the-pod