Hello Minikube
This tutorial shows you how to run a simple Hello World Node.js app on Kubernetes using Minikube and Katacoda. Katacoda provides a free, in-browser Kubernetes environment.
Note: You can also follow this tutorial if you’ve installed Minikube locally.
- Objectives
- Before you begin
- Create a Minikube cluster
- Create a Deployment
- Create a Service
- Enable addons
- Clean up
- What's next
Objectives
- Deploy a hello world application to Minikube.
- Run the app.
- View application logs.
Before you begin
This tutorial provides a container image built from the following files:
minikube/server.js
|
---|
|
minikube/Dockerfile
|
---|
|
For more information on the docker build
command, read the Docker documentation.
Create a Minikube cluster
Click Launch Terminal
Note: If you installed Minikube locally, runminikube start
.Open the Kubernetes dashboard in a browser:
minikube dashboard
Katacoda environment only: At the top of the terminal pane, click the plus sign, and then click Select port to view on Host 1.
Katacoda environment only: Type
30000
, and then click Display Port.
Create a Deployment
A Kubernetes Pod is a group of one or more Containers, tied together for the purposes of administration and networking. The Pod in this tutorial has only one Container. A Kubernetes Deployment checks on the health of your Pod and restarts the Pod’s Container if it terminates. Deployments are the recommended way to manage the creation and scaling of Pods.
Use the
kubectl create
command to create a Deployment that manages a Pod. The Pod runs a Container based on the provided Docker image.kubectl create deployment hello-node --image=gcr.io/hello-minikube-zero-install/hello-node
View the Deployment:
kubectl get deployments
The output is similar to:
NAME READY UP-TO-DATE AVAILABLE AGE hello-node 1/1 1 1 1m
View the Pod:
kubectl get pods
The output is similar to:
NAME READY STATUS RESTARTS AGE hello-node-5f76cf6ccf-br9b5 1/1 Running 0 1m
View cluster events:
kubectl get events
View the
kubectl
configuration:kubectl config view
Note: For more information aboutkubectl
commands, see the kubectl overview.
Create a Service
By default, the Pod is only accessible by its internal IP address within the
Kubernetes cluster. To make the hello-node
Container accessible from outside the
Kubernetes virtual network, you have to expose the Pod as a
Kubernetes Service.
Expose the Pod to the public internet using the
kubectl expose
command:kubectl expose deployment hello-node --type=LoadBalancer --port=8080
The
--type=LoadBalancer
flag indicates that you want to expose your Service outside of the cluster.View the Service you just created:
kubectl get services
The output is similar to:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE hello-node LoadBalancer 10.108.144.78 <pending> 8080:30369/TCP 21s kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 23m
On cloud providers that support load balancers, an external IP address would be provisioned to access the Service. On Minikube, the
LoadBalancer
type makes the Service accessible through theminikube service
command.Run the following command:
minikube service hello-node
Katacoda environment only: Click the plus sign, and then click Select port to view on Host 1.
Katacoda environment only: Note the 5 digit port number displayed opposite to
8080
in services output. This port number is randomly generated and it can be different for you. Type your number in the port number text box, then click Display Port. Using the example from earlier, you would type30369
.This opens up a browser window that serves your app and shows the “Hello World” message.
Enable addons
Minikube has a set of built-in addonsResources that extend the functionality of Kubernetes. that can be enabled, disabled and opened in the local Kubernetes environment.
List the currently supported addons:
minikube addons list
The output is similar to:
addon-manager: enabled dashboard: enabled default-storageclass: enabled efk: disabled freshpod: disabled gvisor: disabled helm-tiller: disabled ingress: disabled ingress-dns: disabled logviewer: disabled metrics-server: disabled nvidia-driver-installer: disabled nvidia-gpu-device-plugin: disabled registry: disabled registry-creds: disabled storage-provisioner: enabled storage-provisioner-gluster: disabled
Enable an addon, for example,
metrics-server
:minikube addons enable metrics-server
The output is similar to:
metrics-server was successfully enabled
View the Pod and Service you just created:
kubectl get pod,svc -n kube-system
The output is similar to:
NAME READY STATUS RESTARTS AGE pod/coredns-5644d7b6d9-mh9ll 1/1 Running 0 34m pod/coredns-5644d7b6d9-pqd2t 1/1 Running 0 34m pod/metrics-server-67fb648c5 1/1 Running 0 26s pod/etcd-minikube 1/1 Running 0 34m pod/influxdb-grafana-b29w8 2/2 Running 0 26s pod/kube-addon-manager-minikube 1/1 Running 0 34m pod/kube-apiserver-minikube 1/1 Running 0 34m pod/kube-controller-manager-minikube 1/1 Running 0 34m pod/kube-proxy-rnlps 1/1 Running 0 34m pod/kube-scheduler-minikube 1/1 Running 0 34m pod/storage-provisioner 1/1 Running 0 34m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/metrics-server ClusterIP 10.96.241.45 <none> 80/TCP 26s service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP 34m service/monitoring-grafana NodePort 10.99.24.54 <none> 80:30002/TCP 26s service/monitoring-influxdb ClusterIP 10.111.169.94 <none> 8083/TCP,8086/TCP 26s
Disable
metrics-server
:minikube addons disable metrics-server
The output is similar to:
metrics-server was successfully disabled
Clean up
Now you can clean up the resources you created in your cluster:
kubectl delete service hello-node
kubectl delete deployment hello-node
Optionally, stop the Minikube virtual machine (VM):
minikube stop
Optionally, delete the Minikube VM:
minikube delete
What's next
- Learn more about Deployment objects.
- Learn more about Deploying applications.
- Learn more about Service objects.
Feedback
Was this page helpful?
Thanks for the feedback. If you have a specific, answerable question about how to use Kubernetes, ask it on Stack Overflow. Open an issue in the GitHub repo if you want to report a problem or suggest an improvement.