Installation using Kubespray

The guide is to use Kubespray for creating an AWS Kubernetes cluster running Cilium as the CNI. The guide uses:

Please consult Kubespray Prerequisites and Cilium System Requirements.

Installing Kubespray

  1. $ git clone --branch v2.6.0 https://github.com/kubernetes-sigs/kubespray

Install dependencies from requirements.txt

  1. $ cd kubespray
  2. $ sudo pip install -r requirements.txt

Infrastructure Provisioning

We will use Terraform for provisioning AWS infrastructure.

Configure AWS credentials

Export the variables for your AWS credentials

  1. export AWS_ACCESS_KEY_ID="www"
  2. export AWS_SECRET_ACCESS_KEY ="xxx"
  3. export AWS_SSH_KEY_NAME="yyy"
  4. export AWS_DEFAULT_REGION="zzz"

Configure Terraform Variables

We will start by specifying the infrastructure needed for the Kubernetes cluster.

  1. $ cd contrib/terraform/aws
  2. $ cp contrib/terraform/aws/terraform.tfvars.example terraform.tfvars`

Open the file and change any defaults particularly, the number of master, etcd, and worker nodes. You can change the master and etcd number to 1 for deployments that don’t need high availability. By default, this tutorial will create:

  • VPC with 2 public and private subnets
  • Bastion Hosts and NAT Gateways in the Public Subnet
  • Three of each (masters, etcd, and worker nodes) in the Private Subnet
  • AWS ELB in the Public Subnet for accessing the Kubernetes API from the internet
  • Terraform scripts using CoreOS as base image.

Example terraform.tfvars file:

  1. #Global Vars
  2. aws_cluster_name = "kubespray"
  4. #VPC Vars
  5. aws_vpc_cidr_block = "XXX.XXX.192.0/18"
  6. aws_cidr_subnets_private = ["XXX.XXX.192.0/20","XXX.XXX.208.0/20"]
  7. aws_cidr_subnets_public = ["XXX.XXX.224.0/20","XXX.XXX.240.0/20"]
  9. #Bastion Host
  10. aws_bastion_size = "t2.medium"
  13. #Kubernetes Cluster
  15. aws_kube_master_num = 3
  16. aws_kube_master_size = "t2.medium"
  18. aws_etcd_num = 3
  19. aws_etcd_size = "t2.medium"
  21. aws_kube_worker_num = 3
  22. aws_kube_worker_size = "t2.medium"
  24. #Settings AWS ELB
  26. aws_elb_api_port = 6443
  27. k8s_secure_api_port = 6443
  28. kube_insecure_apiserver_address = "0.0.0.0"

Apply the configuration

terraform init to initialize the following modules

  • module.aws-vpc
  • module.aws-elb
  • module.aws-iam
  1. $ terraform init

Once initialized , execute:

  1. $ terraform plan -out=aws_kubespray_plan

This will generate a file, aws_kubespray_plan, depicting an execution plan of the infrastructure that will be created on AWS. To apply, execute:

  1. $ terraform init
  2. $ terraform apply "aws_kubespray_plan"

Terraform automatically creates an Ansible Inventory file at inventory/hosts.

Installing Kubernetes cluster with Cilium as CNI

Kubespray uses Ansible as its substrate for provisioning and orchestration. Once the infrastructure is created, you can run the Ansible playbook to install Kubernetes and all the required dependencies. Execute the below command in the kubespray clone repo, providing the correct path of the AWS EC2 ssh private key in ansible_ssh_private_key_file=<path to EC2 SSH private key file>

We recommend using the latest released Cilium version by editing roles/download/defaults/main.yml. Open the file, search for cilium_version, and replace the version with the latest released. As an example, the updated version entry will look like: cilium_version: "v1.2.0".

  1. $ ansible-playbook -i ./inventory/hosts ./cluster.yml -e ansible_user=core -e bootstrap_os=coreos -e kube_network_plugin=cilium -b --become-user=root --flush-cache  -e ansible_ssh_private_key_file=<path to EC2 SSH private key file>

Validate Cluster

To check if cluster is created successfully, ssh into the bastion host with the user core.

  1. # Get information about the basiton host
  2. $ cat ssh-bastion.conf
  3. $ ssh -i ~/path/to/ec2-key-file.pem core@public_ip_of_bastion_host

Execute the commands below from the bastion host. If kubectl isn’t installed on the bastion host, you can login to the master node to test the below commands. You may need to copy the private key to the bastion host to access the master node.

  1. $ kubectl get nodes
  2. $ kubectl get pods -n kube-system

You should see that nodes are in Ready state and Cilium pods are in Running state

Deploy the connectivity test

You can deploy the “connectivity-check” to test connectivity between pods. It is recommended to create a separate namespace for this.

  1. kubectl create ns cilium-test

Deploy the check with:

  1. kubectl apply -n cilium-test -f https://raw.githubusercontent.com/cilium/cilium/v1.9/examples/kubernetes/connectivity-check/connectivity-check.yaml

It will deploy a series of deployments which will use various connectivity paths to connect to each other. Connectivity paths include with and without service load-balancing and various network policy combinations. The pod name indicates the connectivity variant and the readiness and liveness gate indicates success or failure of the test:

  1. $ kubectl get pods -n cilium-test
  2. NAME                                                     READY   STATUS    RESTARTS   AGE
  3. echo-a-76c5d9bd76-q8d99                                  1/1     Running   0          66s
  4. echo-b-795c4b4f76-9wrrx                                  1/1     Running   0          66s
  5. echo-b-host-6b7fc94b7c-xtsff                             1/1     Running   0          66s
  6. host-to-b-multi-node-clusterip-85476cd779-bpg4b          1/1     Running   0          66s
  7. host-to-b-multi-node-headless-dc6c44cb5-8jdz8            1/1     Running   0          65s
  8. pod-to-a-79546bc469-rl2qq                                1/1     Running   0          66s
  9. pod-to-a-allowed-cnp-58b7f7fb8f-lkq7p                    1/1     Running   0          66s
  10. pod-to-a-denied-cnp-6967cb6f7f-7h9fn                     1/1     Running   0          66s
  11. pod-to-b-intra-node-nodeport-9b487cf89-6ptrt             1/1     Running   0          65s
  12. pod-to-b-multi-node-clusterip-7db5dfdcf7-jkjpw           1/1     Running   0          66s
  13. pod-to-b-multi-node-headless-7d44b85d69-mtscc            1/1     Running   0          66s
  14. pod-to-b-multi-node-nodeport-7ffc76db7c-rrw82            1/1     Running   0          65s
  15. pod-to-external-1111-d56f47579-d79dz                     1/1     Running   0          66s
  16. pod-to-external-fqdn-allow-google-cnp-78986f4bcf-btjn7   1/1     Running   0          66s

Note

If you deploy the connectivity check to a single node cluster, pods that check multi-node functionalities will remain in the Pending state. This is expected since these pods need at least 2 nodes to be scheduled successfully.

Delete Cluster

  1. $ cd contrib/terraform/aws
  2. $ terraform destroy