By Sasikumar Sugumar.

Install Kubernetes in AWS through Kops

A Script for creating kubernetes cluster up and running in AWS through Kops.

Features

• Clean Install Kubernetes.
• Install Kops.
• Install Kubectl.
• Create K8 Cluster.

Getting Started

The easiest way to get started is to clone the repository:

# Get the latest snapshot
git clone https://github.com/sasikumar-sugumar/AWS-Install-Kubernetes-Kops-Shell-Script.git myproject

# Change directory
cd myproject

# Execute Permission
chmod 777 Install-Kubernetes.sh

# Run the Script
./Install-Kubernetes.sh

Prerequisites

• AWS Command Line
• ./jq
• The IAM user to create the Kubernetes cluster must have the following permissions:
  • AmazonEC2FullAccess
  • AmazonRoute53FullAccess
  • AmazonS3FullAccess
  • IAMFullAccess
  • AmazonVPCFullAccess
• A Valid domain

Installing

Resource Record Set Template

The Record Set Template with placeholder is processed in runtime and replaced with real values

k8-sub-domian.json
{
    "Comment": "$COMMENT",
    "Changes": [{
        "Action": "CREATE",
        "ResourceRecordSet": {
            "Name": "$SUBDOMAINNAME",
            "Type": "NS",
            "TTL": 300,
            "ResourceRecords": [{
                    "Value": "$VALUE1"
                },
                {
                    "Value": "$VALUE2"
                },
                {
                    "Value": "$VALUE3"
                },
                {
                    "Value": "$VALUE4"
                }
            ]
        }
    }]
}

User Menu Prompt

             M A I N - M E N U

           1. Clean Install Kubernetes
           2. Install kops
           3. Install Kubectl
           4. Create K8 Cluster

           Enter your choice [1-4]

Clean Install Kubernetes

This installs kubernetes from scratch , following sequence of operations are performed

• installKops : Install kops using the below script

  wget https://github.com/kubernetes/kops/releases/download/1.6.1/kops-linux-amd64
  chmod +x kops-linux-amd64
  sudo mv kops-linux-amd64 /usr/local/bin/kops
  

• installKubectl : Install kubectl using the below script

  curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl
  curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.7.0/bin/linux/amd64/kubectl
  chmod +x ./kubectl
  sudo mv ./kubectl /usr/local/bin/kubectl
  

• createSubDomain.

  • Create Hosted-Zone in route53 for the SUB-DOMAIN provided and write the output to hosted-zone.json in the current directory, e.g as below

        ID=$(uuidgen) && aws route53 create-hosted-zone --name $SUBDOMAIN_NAME --caller-reference $ID >>$HOSTED_ZONE_FILE
    

  • hosted-zone.json

        {
            "HostedZone": {
                "ResourceRecordSetCount": 2, 
                "CallerReference": "55f51815-d8c6-4606-ad42-e13b0ec04fd3", 
                "Config": {
                    "PrivateZone": false
                }, 
                "Id": "/hostedzone/Z3KNE0DHIB7S7X", 
                "Name": "your.subdomain.com."
            }, 
            "DelegationSet": {
                "NameServers": [
                    "ns-479.awsdns-59.com", 
                    "ns-1220.awsdns-24.org", 
                    "ns-1682.awsdns-18.co.uk", 
                    "ns-570.awsdns-07.net"
                ]
            }, 
            "Location": "https://route53.amazonaws.com/2013-04-01/hostedzone/Z3KNE0DHIB7S7X", 
            "ChangeInfo": {
                "Status": "PENDING", 
                "SubmittedAt": "2017-08-27T02:41:58.809Z", 
                "Id": "/change/C1CFYDZW9Y2O5Q"
            }
        }
    

• createResourceRecordSet.

  • Replace the placeholders in k8-sub-domian.json template with the actual value using hosted-zone.json and user provided sub-domain , the result would look something like below.

    {
    "Comment": "k8 subdomain your.subdomain.com",
    "Changes": [
        {
        "Action": "CREATE",
        "ResourceRecordSet": {
            "Name": "your.subdomain.com",
            "Type": "NS",
            "TTL": 300,
            "ResourceRecords": [
            {
                "Value": "ns-479.awsdns-59.com"
            },
            {
                "Value": "ns-1220.awsdns-24.org"
            },
            {
                "Value": "ns-1682.awsdns-18.co.uk"
            },
            {
                "Value": "ns-570.awsdns-07.net"
            }
            ]
        }
        }
    ]
    }
    

• createRecordInParentDomain.

  • Get the parent domain hosted zone id.

    PARENT_HOSTED_ZONE_ID=$(aws route53 list-hosted-zones | jq --raw-output '. | .HostedZones[0].Id')
    

  • Create a record in the parent domain using the k8-sub-domain.json and grab the Change ID

    CHANGE_ID=$(aws route53 change-resource-record-sets \
        --hosted-zone-id $PARENT_HOSTED_ZONE_ID \
        --change-batch file://$KOPS_HOME/k8-sub-domain.json | jq --raw-output '. | .ChangeInfo.Id')
    

• waitForINSYNC.

  • Wait until the DNS Change takes effect (look for the status INSYNC)

    while [[ $CHANGE_STATUS == "PENDING" ]]; do
    echo "TAKING A NAP FOR 5S"
    sleep 5s
    CHANGE_STATUS=$(aws route53 get-change --id $CHANGE_ID | jq --raw-output '. | .ChangeInfo.Status')
    echo "CHANGE Status : $CHANGE_STATUS"
    done
    

• createCluster.

  • Once the status of the DNS change is INSYNC, create SSH Keys.

    #create directory for subdomain
    mkdir -p $KOPS_HOME/$SUBDOMAIN_NAME
    touch $KUBE_CONFIG_HOME
    export KUBECONFIG="$KUBE_CONFIG_HOME"
    # create ssh key home
    mkdir $SSH_KEY_HOME
    # generate ssh key
    ssh-keygen -f $SSH_KEY_HOME/id_rsa -t rsa #save the key in the sshkeys
    

  • Create the S3 Bucket using the SUB-DOMAIN (e.g : SUB-DOMAIN-kubernetes-state) and export KOPS_STATE_STORE

    aws s3 rb s3://$SUBDOMAIN_NAME-kubernetes-state
    aws s3 mb s3://$SUBDOMAIN_NAME-kubernetes-state --region us-east-1
    export KOPS_STATE_STORE=s3://$SUBDOMAIN_NAME-kubernetes-state
    

  • Create and update cluster running --yes

    kops create cluster --v=0 \
            --cloud=aws \
            --node-count 2 \
            --master-size=t2.medium \
            --master-zones=us-east-1a \
            --zones us-east-1a,us-east-1b \
            --name=$SUBDOMAIN_NAME \
            --node-size=m3.xlarge \
            --ssh-public-key=$SSH_PUBLIC_KEY \
            --dns-zone $SUBDOMAIN_NAME \
            2>&1 | tee $KOPS_HOME/create_cluster.txt  
    
    kops update cluster $SUBDOMAIN_NAME --yes