K
Q

How to access a server on kubernetes from your local machine?

4/3/2020

My company has a kubernetes platform on which I have a pod ingress running on a namespace my_namespace:

apiVersion: v1
kind: Pod
metadata:
 name: ingress
 labels:
  app: ingress
spec:
 containers:
  - name: ingress
    image: docker:5000/mma/neurotec-ingress
    imagePullPolicy: Always

kubectl get pods -n my_namespace

NAME            READY   STATUS    RESTARTS   AGE
ingress         1/1     Running   1          11d

The pod is a server that listens on port 8080.

I also have a service defined that exports the pod to the outside:

apiVersion: v1
kind: Service
metadata:
  name: ingress
  labels:
    app: ingress
spec:
  ports:
  - port: 8080
    protocol: TCP
  selector:
    app: ingress
  type: LoadBalancer

kubectl describe service -n my_namespace ingress

Name:              ingress
Namespace:         my_namespace
Labels:            app=ingress
Selector:          app=ingress
Type:              LoadBalancer
IP:                10.104.95.96
Port:              <unset>  8080/TCP
TargetPort:        8080/TCP
Endpoints:         10.16.1.232:8080

I now want to send message to the server from my local computer. First thing I want to do is to make sure that its IP address is reachable. However, a simple host command returns errors:

host 10.16.1.232
Host 10.16.1.232 not found: 3(NXDOMAIN)

host ingress.my_namespace.nt // .nt is company's prefix
Host ingress.my_namespace not found: 3(NXDOMAIN)

and if I try to run telepresence it also returns an error:

Looks like there's a bug in our code. Sorry about that!

Traceback (most recent call last):
  File "/usr/bin/telepresence/telepresence/cli.py", line 135, in crash_reporting
    yield
  File "/usr/bin/telepresence/telepresence/main.py", line 65, in main
    remote_info = start_proxy(runner)
  File "/usr/bin/telepresence/telepresence/proxy/__init__.py", line 138, in start_proxy
    run_id=run_id,
  File "/usr/bin/telepresence/telepresence/proxy/remote.py", line 144, in get_remote_info
    runner, deployment_name, deployment_type, run_id=run_id
  File "/usr/bin/telepresence/telepresence/proxy/remote.py", line 91, in get_deployment_json
    return json.loads(output)["items"][0]
IndexError: list index out of range

Question: how to reach a server on kubernetes from your local machine?

-- mercury0114
host
kubernetes
service

Similar Questions

How to handle K8s preStop hook in ASP.NET Core?
How to config coredns with multi namespaces in kubernetes, to achive pods in each namespace gets it own dns resolution
Consuming a web api inside a web application project when using Kubernetes enabled in Docker Desktop and Helm
Cannot patch Kubernetes custom resource from Python SDK

1 Answer

4/3/2020

I think you should use service type: LoadBalancer. (not ClusterIP)

from kubernetes documentation

  • ClusterIP: Exposes the Service on a cluster-internal IP. Choosing this value makes the Service only reachable from within the cluster. This is the default ServiceType.
  • LoadBalancer: Exposes the Service externally using a cloud provider’s load balancer. NodePort and ClusterIP Services, to which the external load balancer routes, are automatically created.

Below is my sample loadbalaner service file. I exposed port 80 to the internet and map port 80 to pod with label run: my-web-portal port 8000.

apiVersion: v1
kind: Service
metadata:
  name: my-web-portal-svc
  labels:
    run: my-web-portal-svc
spec:
  ports:
  - port: 80
    targetPort: 8000
    protocol: TCP
    name: port-80
  selector:
    run: my-web-portal
  type: LoadBalancer

and here is my deployments yml file

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-web-portal
spec:
  selector:
    matchLabels:
      run: my-web-portal
  replicas: 1

  template:
    metadata:
      labels:
        run: my-web-portal

    spec:
      containers:
      - name: backend
        image: xxxxxx-backend

to get endpoints, I run command

kubectl describe service my-web-portal-svc

Command will print out the endpoints which used to connect to your pods

Type:                     LoadBalancer
IP:                       10.100.108.141
LoadBalancer Ingress:     xxxxxxxxxxxxxx.us-west-2.elb.amazonaws.com

Leave comments if you have any questions.

-- Piyapan Poomsirivilai
Source: StackOverflow