Tunneling from kubernetes to dev machine via Headless Service and Endpoint - kubernetes

I'm trying to use a headless service with an endpoint to forward traffic from within my cluster to my local development machine. I want to listen on port 80 on the service and call port 5002 on the endpoint. I have it setup as so:
Headless Service (listening on port 80 with a targetPort of 5002):
Endpoint (pointing to my development computer on port 5002):
When I try to curl http://web:80 from any pod in my cluster on port 80 it times out. If I curl http://web:5002 it successfully goes through and hits my development machine. Shouldn't the targetPort make the request to web:80 go to my endpoint on port 5002?
curl web:80
curl web:5002
Some additional info:
My cluster and dev machine are in the same local network
I'm using K3S on the cluster
I'm just trying to emulate what Bridge For Kubernetes does
Here is the manifest yaml:
apiVersion: v1
kind: Service
metadata:
name: web
namespace: default
spec:
clusterIP: None
ports:
- name: web
port: 80
targetPort: 5002
---
apiVersion: v1
kind: Endpoints
metadata:
name: web
namespace: default
subsets:
- addresses:
- ip: $HOST_IP
ports:
- name: web
port: 5002
protocol: TCP

I managed to get it to work by removing the clusterIP: None. My manifest now looks like this:
apiVersion: v1
kind: Service
metadata:
name: web
spec:
type: ClusterIP
ports:
- name: web
port: 80
targetPort: 5002
---
apiVersion: v1
kind: Endpoints
metadata:
name: web
subsets:
- addresses:
- ip: $HOST_IP
ports:
- name: web
port: 5002

Related

Cannot connect to Kubernetes NodePort Service

I have a running pod that was created with the following pod-definition.yaml:
apiVersion: v1
kind: Pod
metadata:
name: microservice-one-pod-name
labels:
app: microservice-one-app-label
type: front-end
spec:
containers:
- name: microservice-one
image: vismarkjuarez1994/microserviceone
ports:
- containerPort: 2019
I then created a Service using the following service-definition.yaml:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 30008
targetPort: 2019
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
I then ran kubectl describe node minikube to find the Node IP I should be connecting to -- which yielded:
Addresses:
InternalIP: 192.168.49.2
Hostname: minikube
But I get no response when I run the following curl command:
curl 192.168.49.2:30008
The request also times out when I try to access 192.168.49.2:30008 from a browser.
The pod logs show that the container is up and running. Why can't I access my Service?
The problem is that you are trying to access your service at the port parameter which is the internal port at which the service will be exposed, even when using NodePort type.
The parameter you were searching is called nodePort, which can optionally be specified together with port and targetPort. Quoting the documentation:
By default and for convenience, the Kubernetes control plane will
allocate a port from a range (default: 30000-32767)
Since you didn't specify the nodePort, one in the range was automatically picked up. You can check which one by:
kubectl get svc -owide
And then access your service externally at that port.
As an alternative, you can change your service definition to be something like:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 30008
targetPort: 2019
nodePort: 30008
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
But take in mind that you may need to delete your service and create it again in order to change the nodePort allocated.
I think you missed the Port in your service:
apiVersion: v1
kind: Pod
metadata:
name: microservice-one-pod-name
labels:
app: microservice-one-app-label
type: front-end
spec:
containers:
- name: microservice-one
image: vismarkjuarez1994/microserviceone
ports:
- containerPort: 2019
and your service should be like this:
kind: Service
apiVersion: v1
metadata:
name: microserviceone-service
spec:
ports:
- port: 2019
targetPort: 2019
nodePort: 30008
protocol: TCP
selector:
app: microservice-one-app-label
type: NodePort
You can access to your app after enabling the Minikube ingress if you want trying Ingress with Minikube.
minikube addons enable ingress

How to configure ingress rule for redirecting to IP based url rather than service name

i have ingress file where i am forwarding request to pods using service name but i have a scenario where few requests with path /abc* needs to be forwarded to ip based url say http://10.10.1.1:8080/. How to do this case using ingress in Kubernetes and i am using AWS EKS as my kubernetes.
You can create Service using Endpoints for that:
apiVersion: v1
kind: Service
metadata:
name: my-service
spec:
ports:
- protocol: TCP
port: 8080
targetPort: 8080
---
apiVersion: v1
kind: Endpoints
metadata:
name: my-service
subsets:
- addresses:
- ip: 10.10.1.1
ports:
- port: 8080

How can I proxy an external site through my Kubernetes(OpenShift) Ingress?

I have a website that needs to be proxied through my web app.
Traditionally we've accomplished it via apache proxy with proxy directives.
The proxy also rewrites some of the headers and adds a couple of new ones.
Now the app has moved to OpenShift (Kubernetes) and I'm trying to avoid deploying another pod with apache.
Can I perform this header rewriting and proxying via K8 ingress? or router?
I've tried this approach, but it didn't work.
I also don't know how to get OpenShift Ingress logs, nothing seems to happen in there.
I tried using an external name, but it doesn't work:
kind: Service
metadata:
name: es3
spec:
externalName: google.com
type: ExternalName
---
kind: Route
apiVersion: route.openshift.io/v1
spec:
host: host.my-cluster-url.net
to:
kind: Service
name: es3
port:
targetPort: es3
I also tried using Endpoints , same result
apiVersion: v1
kind: Service
metadata:
name: mysvc
spec:
ports:
- name: app
port: 80
protocol: TCP
targetPort: 80
clusterIP: None
type: ClusterIP
---
apiVersion: v1
kind: Endpoints
metadata:
name: mysvc
subsets:
- addresses:
- ip: my.ip.address
ports:
- name: app
port: 80
protocol: TCP
you want to proxy non kubernetes service, right? if yes, use end point and create service from end point, I have used this with kubernetes will work with openshift too my wild guess
https://kubernetes.io/docs/concepts/services-networking/endpoint-slices/

Unable to access service in Kubernetes

I've got this webserver config:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: webserver
spec:
replicas: 1
template:
metadata:
labels:
app: webserver
spec:
containers:
- name: webserver
image: nginx:alpine
ports:
- containerPort: 80
volumeMounts:
- name: hostvol
mountPath: /usr/share/nginx/html
volumes:
- name: hostvol
hostPath:
path: /home/docker/vol
and this web service config:
apiVersion: v1
kind: Service
metadata:
name: web-service
labels:
run: web-service
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
protocol: TCP
selector:
app: webserver
I was expecting to be able to connect to the webserver via http://192.168.99.100:80 with this config but Chrome gives me a ERR_CONNECTION_REFUSED.
I tried minikube service --url web-service which gives http://192.168.99.100:30276 however this also has a ERR_CONNECTION_REFUSED.
Any further suggestions?
UPDATE
I updated the port / targetPort to 80.
However, I now get:
ERR_CONNECTION_REFUSED for http://192.168.99.100:80/
and
an nginx 403 for http://192.168.99.100:31540/
In your service, you can define a nodePort
apiVersion: v1
kind: Service
metadata:
name: web-service
labels:
run: web-service
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
nodePort: 32700
protocol: TCP
selector:
app: webserver
Now, you will be able to access it on http://:32700
Be careful with port 80. Ideally, you would have an nginx ingress controller running on port 80 and all traffic will be routed through it. Using port 80 as nodePort will mess up your deployment.
In your service, you did not specify a targetPort, so the service is using the port value as targetPort, however your container is listening on 80. Add a targetPort: 80 to the service.
NodePort port range varies from 30000-32767(default). When you expose a service without specifying a port, kubernetes picks up a random port from the above range and provide you.
You can check the port by typing the below command
kubectl get svc
In your case - the application is port forwarded to 31540. Your issues seems to be the niginx configuration. Check for the nginx logs.
Please check permissions of mounted volume /home/docker/vol
To fix this you have to make the mounted directory and its contents publicly readable:
chmod -R o+rX /home/docker/vol

access a external service running on a vm form inside kubernetes pod

I have a cluster in aws and using kubernetes.
I have an app running on a machine (vm) in the same network as the cluster
in my browser i can type http://ipaddress:port/status and i get a response
In my pod i can ping the ip address and i get a response but if i do wget://ipaddress:port/status it doesn't connect.
I have tried some things but not able to succeed.
How do i get the pod in the cluster to be be able to open this url, what do I need to do?
You can integrate external services within kubernetes.
endpoint.yaml
kind: Endpoints
apiVersion: v1
metadata:
name: external-ip-database
subsets:
- addresses:
- ip: 192.168.0.1
ports:
- port: 3306
service.yaml
apiVersion: v1
kind: Service
metadata:
name: database
spec:
ports:
- port: 1433
targetPort: 1433
protocol: TCP
---
# Because this service has no selector, the corresponding Endpoints
# object will not be created. You can manually map the service to
# your own specific endpoints:
kind: Endpoints
apiVersion: v1
metadata:
name: database
subsets:
- addresses:
- ip: "192.168.1.103"
ports:
- port: 1433