I have configured a Kubernetes cluster using kubeadm, by creating 3 Virtualbox nodes, each node running CentOS (master, node1, node2). Each virtualbox virtual machine is configured using 'Bridge' networking. As a result, I have the following setup:
Now I would like to access services running in the cluster from my local machine (the physical machine where the virtualbox nodes are running).
Running kubectl cluster-info I see the following output:
Kubernetes master is running at https://192.168.19.87:6443
KubeDNS is running at ...
As an example, let's say I deploy the dashboard inside my cluster, how do I open the dashboard UI using a browser running on my physical machine?
The traditional way is to use kubectl proxy or a Load Balancer, but since you are in a development machine a NodePort can be used to publish the applications, as a Load balancer is not available in VirtualBox.
The following example deploys 3 replicas of an echo server running nginx and publishes the http port using a NodePort:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 3
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: my-echo
image: gcr.io/google_containers/echoserver:1.8
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service-np
labels:
name: nginx-service-np
spec:
type: NodePort
ports:
- port: 8082 # Cluster IP http://10.109.199.234:8082
targetPort: 8080 # Application port
nodePort: 30000 # Example (EXTERNAL-IP VirtualBox IPs) http://192.168.50.11:30000/ http://192.168.50.12:30000/ http://192.168.50.13:30000/
protocol: TCP
name: http
selector:
app: nginx
You can access the servers using any of the VirtualBox IPs, like http://192.168.50.11:30000 or http://192.168.50.12:30000 or http://192.168.50.13:30000
See a full example at Building a Kubernetes Cluster with Vagrant and Ansible (without Minikube).