My aim is to get a basic understanding of Node.js, Docker and Kubernetes and the way to do that is to build something combing all three. So this is what we are going to do:
Step 1: Build a simple Node.js app
Step 2: Containerize the app using Docker
Step 3: Create a Kubernates cluster in AWS EC2 instance
Step 4: Deploy to a Kubernetes Cluster
Step 5: Expose and scale
Step 6: Happy Days! Time to celebrate :)
Step 1: Build a simple Node.js
Node.js is a platform built on Chrome's JavaScript runtime for easily building fast and scalable network applications.
Install Node.js
https://nodejs.org/en/
We will display "Hello world" in a web browser. I have recreated the hello world app from Node.js docs
Run the web server
node helloWorld.js
Navigate to localhost:3000 and you should see the message "Hello world"
Step 2: Containerize the app using Docker
Install Docker for windows
https://www.docker.com/products/docker-desktop
Once installation is complete, start docker
Run the following commands in any terminal to see more information about the installed docker
docker info
create a DOCKERFILE with the following details:
In the terminal where the DOCKERFILE is located, run the following command:
docker build -t hello-world .
We now have a docker image
You can explore all images by executing
docker images
Create an account on docker hub
Tag your docker image with your docker username/ID
docker tag hello-world <<docker_username>>/hello-world
Push the image to docker hub. Make sure that you are signed into docker desktop with your docker id.
docker push <<docker_username>>/hello-world
hello-world docker image is now on docker-hub
verify that its working by starting the first docker container:
docker run --name server-container -p 3000:3000 -d <<docker_username>>/hello-world
To view a list of all containers:
docker ps
Step 3: Create a Kubernates cluster in AWS EC2 instance
In AWS there are three ways to run kubernetes and I am going to attempt the EC2 path:
Install AWS CLI
Configuring the AWS CLI
Create an AWS account if you don't already have you
Log into the AWS Management Console
Add a new IAM user
Note down the access key ID and secret access key.
Use the access key ID and secret key to configure the AWS CLI
aws configure
enter the values when prompted
enter the region name according to your preferred region. I chose ap-southeast-2
Install Kubectl
The Kubernetes command-line tool, kubectl, allows you to run commands against Kubernetes clusters.
docker for windows installs its owns version of kubectl. check version with
kubectl version
Install Kops for windows
kops helps you create, destroy, upgrade and maintain production-grade, highly available, Kubernetes clusters from the command line
https://github.com/kubernetes/kops#installing
Now that we have our tools ready, lets create the kubernetes cluster in AWS. To achieve this we need an S3 bucket to store kops configuration, a route 53 domain and a new ssh key. Lets go and create these.
Create S3 bucket by executing the following in AWS CLI
aws s3api create-bucket --bucket hello-world-kops-state-store --region ap-southeast-2 --create-bucket-configuration LocationConstraint=ap-southeast-2
Enable verisioning on s3 bucket
aws s3api put-bucket-versioning --bucket hello-world-kops-state-store --versioning-configuration Status=Enabled
Create a route 53 domain
aws route53 create-hosted-zone --name k8s.local --caller-reference 1
Generate a new ssh key locally
ssh-keygen -t rsa -C "mouna1619@gmail.com"
Create a new ssh public key called admin and create a secret
kops create secret --state s3://hello-world-kops-state-store --name k8s.local sshpublickey admin -i id_rsa.pub
Now we are ready to create the cluster configuration
kops create cluster --node-count=2 --node-size=a1.medium --zones=ap-southeast-2a --name=k8s.local --state=s3://hello-world-kops-state-store
To find all the zones in a region in aws:
aws ec2 describe-availability-zones --region ap-southeast-2
This will create a cluster with name k8s.local
Once this is done, you can update the cluster
kops update cluster k8s.local --yes --state=s3://hello-world-kops-state-store
It does take some time for the infrastructure to be ready. You can validate the cluster by:
kops validate cluster --state s3://hello-world-kops-state-store
Step 4: Deploy to a Kubernetes Cluster
Step 5: Expose and scale
Troubleshooting
1. If your nodes fails to start and you see a validation errors message like this:
check the status of each node by:
kubectl --namespace=kube-system describe pod <<pod_name>>
kubectl --namespace=kube-system describe pod kube-dns-57dd96bb49-kvlws
Resources:
AWS CLI
https://docs.aws.amazon.com/cli/latest/userguide/install-windows.html#install-msi-on-windows
https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-configure.html?sc_icampaign=docs-cli-config&sc_iplace=docs-bottom
Kubernetes and kops
http://christopher5106.github.io/continous/deployment/2016/05/02/deploy-instantly-from-your-host-to-AWS-EC2-and-Google-Cloud-with-kubernetes.html
https://github.com/kubernetes/kops#installing
https://medium.com/@jandavid.staerk/why-kubernetes-is-awesome-9f7ff0186996
https://kubernetes.io/docs/setup/production-environment/tools/kops/
https://medium.com/containermind/how-to-create-a-kubernetes-cluster-on-aws-in-few-minutes-89dda10354f4
SSH keys
https://confluence.atlassian.com/bitbucketserver/creating-ssh-keys-776639788.html
