Deploy Charmed PostgreSQL K8s on EKS

Amazon Elastic Kubernetes Service (EKS) is a popular, fully automated Kubernetes service. To access the EKS Web interface, go to console.aws.amazon.com/eks/home.

Summary

• Install EKS and Juju tooling
• Create a new EKS cluster
• Bootstrap Juju on GKE
• Deploy charms
• Display deployment information
• Clean up

Install EKS and Juju tooling

Install Juju and kubectl CLI tools via snap:

sudo snap install juju --classic
sudo snap install kubectl --classic

Follow the installation guides for:

• eksctl - the Amazon EKS CLI
• AWs CLI - the Amazon Web Services CLI

To check they are all correctly installed, you can run the commands demonstrated below with sample outputs:

~$ juju version
3.1.7-ubuntu-amd64

~$ kubectl version --client
Client Version: v1.28.2
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3

~$ eksctl info
eksctl version: 0.159.0
kubectl version: v1.28.2

~$ aws --version
aws-cli/2.13.25 Python/3.11.5 Linux/6.2.0-33-generic exe/x86_64.ubuntu.23 prompt/off

Authenticate

Create an IAM account (or use legacy access keys) and login to AWS:

~$ aws configure
AWS Access Key ID [None]: SECRET_ACCESS_KEY_ID
AWS Secret Access Key [None]: SECRET_ACCESS_KEY_VALUE
Default region name [None]: eu-west-3
Default output format [None]:

~$ aws sts get-caller-identity
{
    "UserId": "1234567890",
    "Account": "1234567890",
    "Arn": "arn:aws:iam::1234567890:root"
}

Create a new EKS cluster

Export the deployment name for further use:

export JUJU_NAME=eks-$USER-$RANDOM

This following examples in this guide will use the location eu-west-3 and K8s v.1.27 - feel free to change this for your own deployment.

Sample cluster.yaml:

~$ cat <<-EOF > cluster.yaml

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
    name: ${JUJU_NAME}
    region: eu-west-3
    version: "1.27"
iam:
  withOIDC: true

addons:
- name: aws-ebs-csi-driver
  wellKnownPolicies:
    ebsCSIController: true

nodeGroups:
    - name: ng-1
      minSize: 3
      maxSize: 5
      iam:
        attachPolicyARNs:
        - arn:aws:iam::aws:policy/AmazonEKSWorkerNodePolicy
        - arn:aws:iam::aws:policy/AmazonEKS_CNI_Policy
        - arn:aws:iam::aws:policy/AmazonEC2ContainerRegistryReadOnly
        - arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore
        - arn:aws:iam::aws:policy/AmazonS3FullAccess
      instancesDistribution:
        maxPrice: 0.15
        instanceTypes: ["m5.xlarge", "m5.2xlarge"] # At least two instance types should be specified
        onDemandBaseCapacity: 0
        onDemandPercentageAboveBaseCapacity: 50
        spotInstancePools: 2
EOF

Bootstrap EKS cluster with the following command:

eksctl create cluster -f cluster.yaml

Sample output:

...
2023-10-12 11:13:58 [ℹ]  using region eu-west-3
2023-10-12 11:13:59 [ℹ]  using Kubernetes version 1.27
...
2023-10-12 11:40:00 [✔]  EKS cluster "eks-taurus-27506" in "eu-west-3" region is ready

Bootstrap Juju on EKS

Add Juju k8s clouds:

juju add-k8s $JUJU_NAME

Bootstrap Juju controller:

juju bootstrap $JUJU_NAME

Create a new Juju model (k8s namespace)

juju add-model welcome

[Optional] Increase DEBUG level if you are troubleshooting charms

juju model-config logging-config='<root>=INFO;unit=DEBUG'

Deploy charms

The following command deploys PostgreSQL K8s, PgBouncer K8s, a TLS certificate provider, and the PostgreSQL Test app:

juju deploy postgresql-k8s-bundle --channel 14/edge --trust
juju deploy postgresql-test-app

We then integrate the test app with the postgresql-k8s app and check the status:

juju integrate postgresql-test-app:first-database postgresql-k8s
juju status --watch 1s

Display deployment information

Display information about the current deployments with the following commands:

~$ kubectl cluster-info 
Kubernetes control plane is running at https://AAAAAAAAAAAAAAAAAAAAAAA.gr7.eu-west-3.eks.amazonaws.com
CoreDNS is running at https://AAAAAAAAAAAAAAAAAAAAAAA.gr7.eu-west-3.eks.amazonaws.com/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

~$ eksctl get cluster -A
NAME			    REGION		EKSCTL   CREATED
eks-taurus-27506	eu-west-3	True

~$ kubectl get node
NAME                                           STATUS   ROLES    AGE   VERSION
ip-192-168-14-61.eu-west-3.compute.internal    Ready    <none>   19m   v1.27.5-eks-43840fb
ip-192-168-51-96.eu-west-3.compute.internal    Ready    <none>   19m   v1.27.5-eks-43840fb
ip-192-168-78-167.eu-west-3.compute.internal   Ready    <none>   19m   v1.27.5-eks-43840fb

Clean up

To clean the EKS cluster, resources and juju cloud, run the following commands:

juju destroy-controller $JUJU_NAME --yes --destroy-all-models --destroy-storage --force
juju remove-cloud $JUJU_NAME

List all services and then delete those that have an associated EXTERNAL-IP value (load balancers, …):

kubectl get svc --all-namespaces
kubectl delete svc <service-name> 

Next, delete the EKS cluster (source: Deleting an Amazon EKS cluster)

eksctl get cluster -A
eksctl delete cluster <cluster_name> --region eu-west-3 --force --disable-nodegroup-eviction

Finally, remove AWS CLI user credentials (to avoid forgetting and leaking):

rm -f ~/.aws/credentials