Learn how to use kubectl and Minikube to run your containerized Node.js application in Kubernetes.
Kentaro Wakayama
September 27, 2017
Minikube is a single node Kubernetes cluster which runs on your laptop in a virtual machine. It provides the possibility to run applications in a production-like environment and avoids the need to use Docker Compose for local development.
In this article series we will demonstrate how to run, debug and set up live reload for your containerized Node.js application in Kubernetes.
You can find the code which we use in this article on GitHub: https://github.com/coder-society/node-minikube-workflow
On OS X you can install Minikube with Homebrew. You can find installation instructions for other platforms here.
$ brew cask install minikubeWe use kubectl to interact with our Kubernetes cluster. It can also be installed with Homebrew. You can find installation instructions for other platforms here.
$ brew install kubectlYou should now be able to start Minikube:
$ minikube start
Starting local Kubernetes v1.7.0 cluster...
Starting VM...
Getting VM IP address...
Moving files into cluster...
Setting up certs...
Starting cluster components...
Connecting to cluster...
Setting up kubeconfig...
Kubectl is now configured to use the cluster.Verify the installation by using kubectl to get the running pods and nodes:
$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system heapster-5z549 1/1 Running 0 5m
kube-system influxdb-grafana-f91mq 2/2 Running 0 5m
kube-system kube-addon-manager-minikube 1/1 Running 0 5m
kube-system kube-dns-910330662-8zdn7 3/3 Running 0 5m
kube-system kubernetes-dashboard-645fn 1/1 Running 0 5m$ kubectl get nodes
NAME STATUS AGE VERSION
minikube Ready 6m v1.7.0Clone the repository and cd into the 1-basic-setup directory. Have a look at our Makefile. It provides some convenient commands to interact with Docker and Minikube:
$ git clone [https://github.com/coder-society/node-minikube-workflow.git](https://github.com/coder-society/node-minikube-workflow.git)
$ cd 1-basic-setupThe make create command connects to the docker host running in the Minikube VM. It builds the docker image and applies the Kubernetes manifest files to the Minikube cluster.
$ make create
Sending build context to Docker daemon 51.7MB
Step 1 : FROM node:8-alpine
---> 7a779c246a41
Step 2 : WORKDIR /src
---> Using cache
---> bf82d455b228
Step 3 : COPY package.json /src/
---> Using cache
---> 971f200e90a2
Step 4 : COPY package-lock.json /src/
---> Using cache
---> 47fed9193df0
Step 5 : RUN npm install
---> Using cache
---> 142db6f23946
Step 6 : ADD . /src
---> b10ee47e048b
Removing intermediate container 816dd54c1523
Step 7 : EXPOSE 3000
---> Running in 1fa3c746d63d
---> 5bac6c4d188a
Removing intermediate container 1fa3c746d63d
Step 8 : CMD npm start
---> Running in e7e4fa77cb1a
---> 3063f2d0165e
Removing intermediate container e7e4fa77cb1a
Successfully built 3063f2d0165e
kubectl apply -f kubernetes/
deployment "node-api" created
service "node-api" createdUse can useminikube service node-api --url to retrieve the API URL. Make a curl request to the API:
$ curl $(minikube service node-api --url)
Hello WorldThe make update command builds the image with a timestamp in the tag name (e.g. tmp-1505147929). The Kubernetes deployment image gets updated via the kubectl set image command.
Open index.js and change the reply value of the route to 'Hello Kubernetes'.
server.route({
method: 'GET',
path: '/',
config: {
handler: (res, reply) => {
reply('Hello Kubernetes');
},
description: 'Hello World route',
tags: ['api'],
},
});Run make update to update the application in Minikube.
$ make update
docker build -t codersociety/node-api:tmp-1505148570 .
Sending build context to Docker daemon 51.77MB
Step 1 : FROM node:8-alpine
---> 016382f39a51
Step 2 : WORKDIR /src
---> Using cache
---> deff3e9a115e
Step 3 : COPY package.json /src/
---> Using cache
---> e2ab0b9845a9
Step 4 : COPY package-lock.json /src/
---> Using cache
---> c815960d9ac8
Step 5 : RUN npm install
---> Using cache
---> b86c65ff6454
Step 6 : ADD . /src
---> 29c7a32c8d0a
Removing intermediate container a12fd5b4f143
Step 7 : EXPOSE 3000
---> Running in 782644f6b740
---> d56d725f3f2b
Removing intermediate container 782644f6b740
Step 8: CMD npm start
---> Running in 16d8f3d2d0dc
---> 6659294b267d
Removing intermediate container 16d8f3d2d0dc
Successfully built 6659294b267d
kubectl set image -f ./kubernetes/deployment.yaml node-api=codersociety/node-api:tmp-1505148570
deployment "node-api" image updatedMake another request to verify your changes:
$ curl $(minikube service node-api --url)
Hello KubernetesThe make delete command simply removes the Kubernetes deployment and service which are defined in the kubernetes directory:
$ make delete
kubectl delete -f kubernetes/
deployment "node-api" deleted
service "node-api" deletedIn the next article we will show you how to debug your Node.js application in Minikube:
https://codersociety.com/articles/node.js-development-workflow-for-kubernetes-debugging-(part-2)
