Set Up Kubernetes Cluster - AWS (4.2)

Before installing Usage Engine Private Edition, you need to set up a Kubernetes cluster on AWS EKS (Amazon's managed Kubernetes Service for EC2).

First a basic Kubernetes cluster needs to be created. This can be done in two different ways:

Using the eksctl CLI tool.
Using the AWS management console.

In this guide, eksctl will be used. Mainly because it will enable you to create the basic Kubernetes cluster in minutes with just a single command.

Once the basic Kubernetes cluster has been created, additional infrastructure needs to be added. For this terraform is used.

Before proceeding, go to Release Information, and download the aws.tar.gz file for the Usage Engine Private Edition version that is being installed. Once downloaded, extract its content to a suitable location.

Assumptions

There are a few assumptions been made when using terraform to create cluster resources:

We assume you have an existing parent domain i.e. example.com hosted on the same account as the cluster that we going to create in the coming section and you wish to access the cluster environment through the hostname. Terraform will create a subdomain in format <cluster_name>.<domain>.
1. cluster name: uepe-eks
2. domain: example.com
3. final domain: uepe-eks.example.com
In addition, we also assume terraform is allowed to add a NS (NameServer) record to the parent domain. This is to allow DNS delegation from the parent domain to subdomain.
Terraform needs to persist the state of your provisioned infrastructure, by default the state file is stored locally on the computer that terraform is executed from. However if you have multiple person working on the infrastructure then it is recommended to store the state file on remote persistent such as S3 bucket, see https://developer.hashicorp.com/terraform/language/settings/backends/s3 for more information.
We use EFS (NFS) as the default persistent storage for data needs to be persisted.
We use RDS for Usage Engine Private Edition database, default engine type is PostgreSQL.

Create Basic Cluster

The following steps explains how to create a basic Kubernetes cluster using a configuration file named uepe-eks.yaml:

Go to <the location where you extracted the aws.tar.gz file>/aws/eksctl and edit theuepe-eks.yaml file.
In the metadata section, specify the desired cluster name, AWS region and Kubernetes version (please refer to the https://infozone.atlassian.net/wiki/x/owDKCg to find out which Kubernetes versions that are compatible with this release of Usage Engine Private Edition).
In the nodeGroups section, specify the desired node size within the cluster. Set minSize and maxSize to specify a limit to the number of node’s minimum and maximum range. Set desiredCapacity to specify the exact number of node running within the cluster. In this example, we are creating a 3 nodes cluster with public and private VPC.

The uepe-eks.yaml configuration file looks like this:

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: example-cluster
  region: eu-west-1
  version: "1.29"
  tags:
    deployment: aws-template

vpc:
  clusterEndpoints:
    publicAccess:  true
    privateAccess: true
    
iam:
  withOIDC: true
  serviceAccounts:
  - metadata:
      name: aws-load-balancer-controller
      namespace: uepe
      labels: {aws-usage: "aws-load-balancer-contoller"}
    wellKnownPolicies:
      awsLoadBalancerController: true
  - metadata:
      name: external-dns
      namespace: uepe
      labels: {aws-usage: "external-dns"}
    wellKnownPolicies:
      externalDNS: true
  - metadata:
      name: cert-manager
      namespace: cert-manager
    wellKnownPolicies:
      certManager: true
  - metadata:
      name: cluster-autoscaler
      namespace: uepe
      labels: {aws-usage: "cluster-ops"}
    wellKnownPolicies:
      autoScaler: true
  - metadata:
      name: efs-csi-controller-sa
      namespace: uepe
      labels: {aws-usage: "aws-efs-csi-driver"}
    wellKnownPolicies:
      efsCSIController: true
  - metadata:
      name: ebs-csi-controller-sa
      namespace: uepe
      labels: {aws-usage: "aws-ebs-csi-driver"}
    wellKnownPolicies:
      ebsCSIController: true

nodeGroups:
  - name: public-nodes
    instanceType: m5.large
    minSize: 3
    maxSize: 3
    desiredCapacity: 3
    volumeSize: 80
    labels: {role: worker}
    volumeEncrypted: true
    tags:
      nodegroup-role: worker

cloudWatch:
  clusterLogging:
    enableTypes: ["*"]

has been configured for each cluster add-on under the iam.serviceAccounts section in the above uepe-eks.yaml file. Hence, a service account for each cluster add-on will be created in the specified namespace respectively.

Please make sure to use the same namespace when installing the respective add-on in the section.

For instance, using the namespaces specified in the uepe-eks.yaml file above, means that:

external-dns must be installed in namespace uepe.
cert-manager must be installed in namespace cert-manager.

Execute the following command to create the cluster based on your desired settings:

eksctl create cluster -f uepe-eks.yaml --kubeconfig=./kubeconfig.yaml

A Kubernetes cluster with the desired number of nodes should be created within 15 minutes.

Also, the above eksctl command will generate a ./kubeconfig.yaml file containing information on how to connect to your newly created cluster. Make sure to set the KUBECONFIG environment variable to point to that file:

export KUBECONFIG=<full path to ./kubeconfig.yaml>

This will ensure that tools like kubectl and helm will connect to your newly created cluster.

You can check the status of the cluster nodes like this:

For this example cluster the output will looks something like this:

Setup Additional Infrastructure Resources on AWS

At this stage, a basic Kubernetes cluster has been created. However, some additional infrastructure resources remain to be set up. Namely the following:

Hosted Zone (subdomain) for domain name.
ACM Certificate for the domain name (to be used with any load balancers).
KMS CMK key which is used for encryption at-rest for EFS, RDS and SSM.
EFS with security group in place.
RDS PostgreSQL with security group in place.

Follow these steps to set up the remaining infrastructure resources:

Go to <the location where you extracted the aws.tar.gz file>/terraform
Copy terraform.tf.vars.example to terraform.tfvars.
Retrieve the following values from AWS Console and fill in the parameters in terraform.tfvars

terraform.tfvars	Where to get the value from?

terraform.tfvars	Where to get the value from?
`vpc_id`	In the AWS management console, you can find this information by searching for “Your VPCs”. Pick the VPC ID of the cluster that you created in the previous section.
`aws_region`	From `metadata.region` in your `uepe-eks.yaml`file.
`aws_account_id`	In the AWS management console, this is the Account ID that is listed on your Account page.
`cluster_name`	From `metadata.name` in your `uepe-eks.yaml` file.
`domain`	In the AWS management console, on the Route 53 service page, this is the Hosted zone name of your existing Hosted zone. The service hostname that created by Usage Engine Private Edition will be accessible in format `<service_name>.<cluster_name>.<domain>` i.e. desktop-online.uepe-eks.example.com.
`domain_zone_id`	In the AWS management console, on the Route 53 service page, this is the Hosted zone ID of your existing Hosted zone.
`db_password`	Choose a secure password for the system database administrator. Minimum 10 characters.
`auto_create_ns_record`	Boolean flag to enable subdomain NS record auto creation in parent domain. In case your parent domain is not under the same account or your parent domain is hosted in another cloud provider, then you must set it to false.

Example:

Important notes if your parent domain zone is not under the same account:

You need to set auto_create_ns_record = false to disable subdomain NS record auto creation in the parent domain.
Terraform apply will fail due to certificate validation timeout error │ Error: waiting for ACM Certificate (arn:aws:acm:ap-southeast-1:027763730008:certificate/84ae1022-15bd-430a-ab3e-278f01b0edb6) to be issued: timeout while waiting for state to become 'ISSUED' (last state: 'PENDING_VALIDATION', timeout: 2m0s)
When the error above happened, you need to manually retrieve the name servers value from the created subdomain and add them to parent domain as NS record. If you are not using Route53 as the parent domain, please refer to your Domain Registrar documentation on how to add NS record.
Once NS record is added to the parent domain, go to AWS Console | AWS Certificate Manager (ACM) and wait for the certificate status become verified. It will take 10-20 minutes.
After the certificate is verified, run the terraform apply again to continue provisioning.

Run the following commands

Wait for the terraform commands to finish.

Make sure to save the output from terraform above. Reason being that it is used as input throughout the remainder of this installation guide.

A Kubernetes cluster has now been created.

This section is now complete and you can proceed to the section.