Kubernetes requires a set of machines to host the Kubernetes control plane and the worker nodes where containers are ultimately run. In this lab you will provision the compute resources required for running a simple Kubernetes cluster across a single compute zone.
The Kubernetes networking model assumes a flat network in which containers and nodes can communicate with each other. In cases where this is not desired network policies can limit how groups of containers are allowed to communicate with each other and external network endpoints.
Setting up network policies is out of scope for this tutorial.
In this section a dedicated Virtual Private Cloud (VPC) network will be setup to host the Kubernetes cluster.
Create the kubernetes-the-hard-way custom VPC:
export myIP=`curl -s ifconfig.co`
export vpcId=`aws ec2 create-vpc --cidr-block 10.0.0.0/16 --query 'Vpc.VpcId' --output text`
export internetGatewayId=`aws ec2 create-internet-gateway --query 'InternetGateway.InternetGatewayId' --output text`
aws ec2 create-tags --resources ${vpcId} --tags Key=Name,Value=kubernetes-the-hard-way
aws ec2 modify-vpc-attribute --vpc-id $vpcId --enable-dns-support "{\"Value\":true}"
aws ec2 modify-vpc-attribute --vpc-id $vpcId --enable-dns-hostnames "{\"Value\":true}"
aws ec2 attach-internet-gateway --internet-gateway-id $internetGatewayId --vpc-id $vpcId
A subnet must be provisioned with an IP address range large enough to assign a private IP address to each node in the Kubernetes cluster.
Create the kubernetes subnet in the kubernetes-the-hard-way VPC:
export subnetId=`aws ec2 create-subnet --vpc-id $vpcId --cidr-block 10.0.10.0/24 --query 'Subnet.SubnetId' --output text`
export routeTableId=`aws ec2 create-route-table --vpc-id $vpcId --query 'RouteTable.RouteTableId' --output text`
aws ec2 associate-route-table --route-table-id $routeTableId --subnet-id $subnetId
aws ec2 create-route --route-table-id $routeTableId --destination-cidr-block 0.0.0.0/0 --gateway-id $internetGatewayId
The
10.240.0.0/24IP address range can host up to 254 compute instances.
Create a firewall rule that allows internal and external (it will use your current external IP address) communication across all protocols:
export securityGroupId=`aws ec2 create-security-group --group-name my-security-group --description "my-security-group" --vpc-id $vpcId --query 'GroupId' --output text`
aws ec2 authorize-security-group-ingress --group-id $securityGroupId --protocol all --cidr 10.0.0.0/16
aws ec2 authorize-security-group-ingress --group-id $securityGroupId --protocol all --cidr ${myIP}/32
An external load balancer with allocated static IP should be used to expose the Kubernetes API Servers to remote clients, but this will not be covered in this tutorial.
The compute instances in this lab will be provisioned using Ubuntu Server 16.04, which has good support for the Docker runtime. Each compute instance will be provisioned with a fixed private IP address to simplify the Kubernetes bootstrapping process. We will use two t2.small instances - controller and worker.
Create EC2 instance which will host the Kubernetes control plane:
export AMI_ID=`aws ec2 describe-images --owners 099720109477 --filters 'Name=name,Values=ubuntu/images/hvm-ssd/ubuntu-xenial-16.04-amd64-server-*' --query 'Images[*].[ImageId,CreationDate]' --output text | sort -k2 -r | head -n1 | cut -f 1`
aws ec2 create-key-pair --key-name kubernetes-the-hard-way --query 'KeyMaterial' --output text > ~/.ssh/kubernetes-the-hard-way.pem
chmod 400 ~/.ssh/kubernetes-the-hard-way.pem
ssh-add ~/.ssh/kubernetes-the-hard-way.pem >/dev/null
export MASTER_ID=`aws ec2 run-instances --image-id ${AMI_ID} --count 1 --instance-type t2.small --key-name kubernetes-the-hard-way --security-group-ids ${securityGroupId} --subnet-id ${subnetId} --private-ip-address 10.0.10.11 --associate-public-ip-address --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=controller}]' --query 'Instances[*].InstanceId' --output text`
export MASTER_EXT_IP=`aws ec2 describe-instances --instance-ids ${MASTER_ID} --query 'Reservations[*].Instances[*].PublicIpAddress' --output text`
Create EC2 instance which will host the Kubernetes worker node:
export WORKER_ID=`aws ec2 run-instances --image-id ${AMI_ID} --count 1 --instance-type t2.small --key-name kubernetes-the-hard-way --security-group-ids ${securityGroupId} --subnet-id ${subnetId} --private-ip-address 10.0.10.21 --associate-public-ip-address --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=worker}]' --query 'Instances[*].InstanceId' --output text`
export WORKER_EXT_IP=`aws ec2 describe-instances --instance-ids ${WORKER_ID} --query 'Reservations[*].Instances[*].PublicIpAddress' --output text`
List the compute instances in your default compute zone:
ssh ubuntu@${MASTER_EXT_IP}
ssh ubuntu@${WORKER_EXT_IP}
You might get a warning about invalid locales. Just follow the guide - install missing package and reload the ssh session.