Set Up Kubernetes Cluster - OCI

Before installing Usage Engine Private Edition, you need to set up a Kubernetes cluster on OCI OKE (Oracle’s managed Kubernetes service).

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

• Using the terraform tool.

• Using the OCI management console.

In this guide, terraform 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 also used.

Before proceeding, go to Release Information, and download the oci.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:

1. 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

2. 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.

3. Please note that 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 auto_create_ns_record to false in the terraform template to disable subdomain NS record auto creation in parent domain.

4. 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.

5. 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.

6. We use the OCI File System service (NFS) as the default persistent storage for data needs to be persisted.

7. We use the OCI Managed PostgreSQL service for Usage Engine Private Edition database.

Create Basic Cluster and additional infrastructure

The following steps explains how to create a basic Kubernetes cluster with public and private VPC:

1. Go to <the location where you extracted the gcp.tar.gz file>/gcp/terraform and copy theterraform.tfvars.example to terraform.tfvars.

2. Edit the terraform.tfvars file.

3. Specify the desired cluster name, GCP region and kubernetes_version prefix (please refer to the Compatibility Matrix (4.1) to find out which Kubernetes versions that are compatible with this release of Usage Engine Private Edition). Also specify your GCP project id (which can be found on the GCP dashboard), as well as the desired number of nodes per region (gke_num_nodes).

4. If you will be running with a database other than Derby also specify db_password, db_version and db_allocated_storage.

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: ["*"]

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:

eksctl get nodegroup --cluster example-cluster

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

CLUSTER         NODEGROUP       STATUS          CREATED                 MIN SIZE    MAX SIZE    DESIRED CAPACITY    INSTANCE TYPE   IMAGE ID                ASG NAME                                                                TYPE
example-cluster public-nodes	CREATE_COMPLETE 2024-03-11T13:59:28Z    3           3           3                   m5.large        ami-02e2de73058d55743   eksctl-example-cluster-nodegroup-public-nodes-NodeGroup-eb5aNADEiibs    unmanaged

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:

1. Go to <the location where you extracted the aws.tar.gz file>/terraform

2. Copy terraform.tf.vars.example to terraform.tfvars.

3. Retrieve the following values from AWS Console and fill in the parameters in terraform.tfvars

Example:

#  ____  _____ _____   _____ _   _ _____ ____  _____
# / ___|| ____|_   _| |_   _| | | | ____/ ___|| ____|_
# \___ \|  _|   | |     | | | |_| |  _| \___ \|  _| (_)
#  ___) | |___  | |     | | |  _  | |___ ___) | |___ _
# |____/|_____| |_|     |_| |_| |_|_____|____/|_____(_)

# The below values must be set explicitly in order for the setup to work correctly.

vpc_id = "vpc-04ff16421e3ccdd94"
aws_region = "eu-west-1"
aws_account_id = "058264429588"

# Name of the cluster, it must be unique in the account.
cluster_name = "example-cluster"

# Domain DNS name
# The DNS zone must already exist in Route53 or in other cloud provider DNS zone.
# We'll create a subdomain zone from parent domain, the final domain will be in format "<cluster_name>.<domain>".
# Please note that if this domain is hosted on another AWS account or other cloud provider, then you must
# set auto_create_ns_record = false and manually add the subdomain NS record to the parent domain.
domain = "stratus.digitalroute.net"

# Admin user password to the database.
db_password = "super_SeCrEt_db_pAsSwOrD_457!"

4. Run the following commands

terraform init
terraform plan
terraform apply

5. Wait for the terraform commands to finish.

Apply complete! Resources: 16 added, 0 changed, 0 destroyed.

Outputs:

certificate_arn = "arn:aws:acm:eu-west-1:058264429588:certificate/526ed179-afa7-4778-b1b8-bfbcb95e4534"
db_endpoint = "example-cluster-db.c70g0ggo8m66.eu-west-1.rds.amazonaws.com:5432"
db_password = <sensitive>
db_user = "dbadmin"
efs_id = "fs-0f0bb5c0ef98f5b6f"
eks_domain_zone_id = "Z076760737OMHF392P9P7"
eks_domain_zone_name = "example-cluster.stratus.digitalroute.net"
name_servers = tolist([
  "ns-1344.awsdns-40.org",
  "ns-2018.awsdns-60.co.uk",
  "ns-55.awsdns-06.com",
  "ns-664.awsdns-19.net",
])
private_subnets = [
  "subnet-0956aa9898f78900d",
  "subnet-0b6d1364dfb4090d6",
  "subnet-0da06b6a88f9f45e7",
]
public_subnets = [
  "subnet-01174b6e86367827b",
  "subnet-0d0b14a68fe42ba09",
  "subnet-0eed6adde0748e1f6",
]

A basic Kubernetes cluster has now been created.

A RDS PostgreSQL database instance up and running on private subnet VPC with default listening port 5432. The default database PlatformDatabase is accessible within the cluster at end point example-cluster-db.c70g0ggo8m66.eu-west-1.rds.amazonaws.com with admin username dbadmin.

Now proceed to the Kubernetes Cluster Add-ons - OCI section.