Skip to content

Instantly share code, notes, and snippets.

@darkn3rd

darkn3rd/provision.md

Last active January 4, 2024 08:30
Show Gist options
  • Star 3 You must be signed in to star a gist
  • Fork 1 You must be signed in to fork a gist
  • Save darkn3rd/d598f124872ed003fe062a7a3f1806ec to your computer and use it in GitHub Desktop.
Save darkn3rd/d598f124872ed003fe062a7a3f1806ec to your computer and use it in GitHub Desktop.
Download ZIP
Pedantic ADHD Guide to Kubernetes Provisioning
Raw
provision.md

Pedantic ADHD Guide to Kubenretes Provisioning

This is my guide for how to get Kubernetes provisioned using Azure, Google Cloud, or AWS using CLI tools. This will require setting up an account with local CLI tools. The goal of this is to quickly set up a disposable test clusters in minimalist way.

The Tools

Some tools used here:

  • General
    • direnv (direnv) - used to setup environment variables automatically
    • asdf (asdf) - used to install kubectl client CLI with version that matches server version
  • Cloud CLI tools
    • Azure CLI (az) - tool used to provision Azure cloud resources
    • AWS CLI (aws) - tool used to provision AWS cloud resources
    • Google Cloud SDK (gcloud) - tool used to provision Google cloud resources
  • Kubernetes Tools
    • Kubectl Client (kubectl) - client tool to interact with Kubernetes cluster
    • Helm (helm) - tool to deploy Kubernetes packages
  • Cloud Provisioning
    • eksctl (eksctl) - tools to easily provision EKS clusters using CLI or yaml file
    • terraform (terraform) - tool used to provision cloud resources and deploy kubernetes objects

Articles related to tools

Provision Kubernetes using CLI tools

Here's a quick and easy way to bring up disposable Kubernetes clusters on Azure, Google Cloud, or AWS using the CLI tools from these cloud providers. Afterward, you can use kubectl, helm, or terraform to deploy applications on Kubernetes.

AKS (Azure Kubenretes Service)

cat <<-'EOF' > .envrc
export AZ_AKS_CLUSTER_NAME="my-aks-cluster"
export AZ_RESOURCE_GROUP="my-aks-cluster-rg"
export AZ_LOCATION="eastus"
export KUBECONFIG="$HOME/.kube/$AZ_LOCATION.$AZ_AKS_CLUSTER_NAME.yaml"
EOF

direnv allow

create_k8s_cluster()
{
  local AZ_AKS_CLUSTER_NAME=${1:-"my-aks-cluster"}
  local AZ_RESOURCE_GROUP=${2:-"my-aks-cluster-rg"}
  local AZ_LOCATION=${3:-"eastus"}

  # provision Kubernetes
  # NOTE: default quota is 2 VMS per location
  az aks create \
    --resource-group ${AZ_RESOURCE_GROUP} \
    --name ${AZ_AKS_CLUSTER_NAME} \
    --node-count 2 \
    --zones 1 2
  
  # configure KUBECONFIG
  az aks get-credentials \
    --resource-group ${AZ_RESOURCE_GROUP} \
    --name ${AZ_AKS_CLUSTER_NAME} \
    --file ${KUBECONFIG}
}

rm -rf $KUBECONFIG # delete any existing KUBECONFIG
# provision kubernetes cluster
az group create --name=$AZ_RESOURCE_GROUP --location=$AZ_LOCATION
create_k8s_cluster $AZ_AKS_CLUSTER_NAME $AZ_RESOURCE_GROUP $AZ_LOCATION

# setup client
SVER=$(kubectl version --short | grep -e Server | grep -oP '(\d+\.){2}\d+')
asdf list kubectl | grep -qo $SVER || asdf install kubectl $SVER
asdf global kubectl $SVER

Cleanup AKS

az aks delete \
  --resource-group ${AZ_RESOURCE_GROUP} \
  --name ${AZ_AKS_CLUSTER_NAME}
    
az group delete \
  --name=$AZ_RESOURCE_GROUP \
  --location=$AZ_LOCATION

rm -rf $KUBECONFIG

GKE (Google Kubernetes Engine)

The default identity principal, fancy term for account, has insecure default privileges. This shows how to setup a basic cluster that uses least privilege. In a nutshell, you don't want to create a cluster whose default account allows itself to grant new privileges. This is dangerous, thus the minimal setup requires a few extra steps.

cat <<-'EOF' > .envrc
export CLOUDSDK_CORE_PROJECT="<your-project-name-goes-here>" # set default project
export GKE_PROJECT_ID=$CLOUDSDK_CORE_PROJECT
export gke_NAME="my-gke-cluster"
export GKE_REGION="us-central1"
export KUBECONFIG="$HOME/.kube/$GKE_REGION.$gke_NAME.yaml"
EOF

direnv allow

create_least_priv_gsa() 
{
  local gke_NAME=${1:-"my-gke-cluster"}
  local GKE_REGION=${2:-"us-central1"}
  local GKE_SA_NAME="$gke_NAME-sa"
  local GKE_SA_EMAIL="$GKE_SA_NAME@${GKE_PROJECT_ID}.iam.gserviceaccount.com"

  ROLES=(
    roles/logging.logWriter
    roles/monitoring.metricWriter
    roles/monitoring.viewer
    roles/stackdriver.resourceMetadata.writer
  )

  gcloud iam service-accounts create $GKE_SA_NAME \
    --display-name $GKE_SA_NAME --project $GKE_PROJECT_ID

  # assign google service account to roles in GKE project
  for ROLE in ${ROLES[*]}; do
    gcloud projects add-iam-policy-binding $GKE_PROJECT_ID \
      --member "serviceAccount:$GKE_SA_EMAIL" \
      --role $ROLE
  done
}

create_k8s_cluster()
{
  local gke_NAME=${1:-"my-gke-cluster"}
  local GKE_REGION=${2:-"us-central1"}
  local GKE_SA_NAME="$gke_NAME-sa"
  local GKE_SA_EMAIL="$GKE_SA_NAME@${GKE_PROJECT_ID}.iam.gserviceaccount.com"

  create_least_priv_gsa $gke_NAME $GKE_REGION

  gcloud container clusters create $gke_NAME \
    --project $GKE_PROJECT_ID --region $GKE_REGION --num-nodes 1 \
    --service-account "$GKE_SA_EMAIL" \
    --workload-pool "$GKE_PROJECT_ID.svc.id.goog"
}

rm -rf $KUBECONFIG # delete any existing KUBECONFIG
create_k8s_cluster $gke_NAME $GKE_REGION

# setup client
SVER=$(kubectl version --short | grep -e Server | grep -oP '(\d+\.){2}\d+')
asdf list kubectl | grep -qo $SVER || asdf install kubectl $SVER
asdf global kubectl $SVER

Cleanup GKE

###
# IMPORTANT: Delete persistent storage (PVC) before deleting cluster to avoid
# leftover cloud resources.
#####
gcloud container clusters delete $gke_NAME \
    --project $GKE_PROJECT_ID --region $GKE_REGION

ROLES=(
  roles/logging.logWriter
  roles/monitoring.metricWriter
  roles/monitoring.viewer
  roles/stackdriver.resourceMetadata.writer
)

GKE_SA_NAME="$gke_NAME-sa"
GKE_SA_EMAIL="$GKE_SA_NAME@${GKE_PROJECT_ID}.iam.gserviceaccount.com"

for ROLE in ${ROLES[*]}; do
  gcloud projects remove-iam-policy-binding$GKE_PROJECT_ID \
    --member "serviceAccount:$GKE_SA_EMAIL" \
    --role $ROLE
done

gcloud iam service-accounts delete $GKE_SA_NAME --project $GKE_PROJECT_ID

EKS (Elastic Kubernetes Service) v1.22 and earlier

EKS is fairly straight forward to setup using eksctl tool. This is a CLI written in go-lang that standups all the necessary components using Cloud Formation. This will setup both the networking components with VPC and the Kubernetes cluster itself.

cat <<-'EOF' > .envrc
export AWS_PROFILE="<your-profile-name-goes-here"  # set profile to utilize
export EKS_CLUSTER_NAME="my-eks-cluster"
export EKS_REGION="us-east-2"
export EKS_VERSION="1.22"
export KUBECONFIG=$HOME/.kube/$EKS_REGION.$EKS_CLUSTER_NAME.yaml
EOF

direnv allow

create_k8s_cluster()
{
  local EKS_CLUSTER_NAME=${1:-"my-eks-cluster"}
  local EKS_REGION=${2:-"us-west-2"}
  local EKS_VERSION=${3:-"1.22"}
 
  eksctl create cluster \
      --region $EKS_REGION \
      --name $EKS_CLUSTER_NAME \
      --version $EKS_VERSION
}

create_k8s_cluster $EKS_CLUSTER_NAME $EKS_REGION $EKS_VERSION

# setup client
SVER=$(kubectl version --short | grep -e Server | grep -oP '(\d+\.){2}\d+')
asdf list kubectl | grep -qo $SVER || asdf install kubectl $SVER
asdf global kubectl $SVER

EKS (Elastic Kubernetes Service) v1.23 and later

Starting with Kubernetes 1.23 and greater, the default storage class no longer works. Thus you cannot use persistent storage any longer until you install a new storage class driver. This obviously makes a default cluster rather complex to setup.

cat <<-'EOF' > .envrc
export AWS_PROFILE="<your-profile-name-goes-here"  # set profile to utilize
export EKS_CLUSTER_NAME="my-eks-cluster"
export EKS_REGION="us-east-2"
export EKS_VERSION="1.25"
export KUBECONFIG=$HOME/.kube/$EKS_REGION.$EKS_CLUSTER_NAME.yaml
EOF

direnv allow

create_k8s_cluster()
{
  local EKS_CLUSTER_NAME=${1:-"my-eks-cluster"}
  local EKS_REGION=${2:-"us-east-2"}
  local EKS_VERSION=${3:-"1.25"}
 
  eksctl create cluster \
      --region $EKS_REGION \
      --name $EKS_CLUSTER_NAME \
      --version $EKS_VERSION 

  ## extra requirements
  eksctl utils associate-iam-oidc-provider \
    --cluster $EKS_CLUSTER_NAME \
    --region=$EKS_REGION \
    --approve

  eksctl create iamserviceaccount \
    --name ebs-csi-controller-sa \
    --namespace kube-system \
    --cluster $EKS_CLUSTER_NAME \
    --attach-policy-arn arn:aws:iam::aws:policy/service-role/AmazonEBSCSIDriverPolicy \
    --approve \
    --role-only \
    --role-name AmazonEKS_EBS_CSI_DriverRole

  cat <<-EOF > policy.json
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "ec2:CreateSnapshot",
        "ec2:AttachVolume",
        "ec2:DetachVolume",
        "ec2:ModifyVolume",
        "ec2:DescribeAvailabilityZones",
        "ec2:DescribeInstances",
        "ec2:DescribeSnapshots",
        "ec2:DescribeTags",
        "ec2:DescribeVolumes",
        "ec2:DescribeVolumesModifications"
      ],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:CreateTags"
      ],
      "Resource": [
        "arn:aws:ec2:*:*:volume/*",
        "arn:aws:ec2:*:*:snapshot/*"
      ],
      "Condition": {
        "StringEquals": {
          "ec2:CreateAction": [
            "CreateVolume",
            "CreateSnapshot"
          ]
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteTags"
      ],
      "Resource": [
        "arn:aws:ec2:*:*:volume/*",
        "arn:aws:ec2:*:*:snapshot/*"
      ]
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:CreateVolume"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "aws:RequestTag/ebs.csi.aws.com/cluster": "true"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:CreateVolume"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "aws:RequestTag/CSIVolumeName": "*"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteVolume"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "ec2:ResourceTag/ebs.csi.aws.com/cluster": "true"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteVolume"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "ec2:ResourceTag/CSIVolumeName": "*"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteVolume"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "ec2:ResourceTag/kubernetes.io/created-for/pvc/name": "*"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteSnapshot"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "ec2:ResourceTag/CSIVolumeSnapshotName": "*"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DeleteSnapshot"
      ],
      "Resource": "*",
      "Condition": {
        "StringLike": {
          "ec2:ResourceTag/ebs.csi.aws.com/cluster": "true"
        }
      }
    }
  ]
}

EOF

  aws iam create-policy \
    --policy-name AmazonEKS_EBS_CSI_DriverRolePolicy \
    --policy-document file://policy.json

  aws iam attach-role-policy \
    --policy-arn arn:aws:iam::$ACCOUNT_ID:policy/AmazonEKS_EBS_CSI_DriverRolePolicy \
    --role-name AmazonEKS_EBS_CSI_DriverRole

  eksctl create addon \
    --name aws-ebs-csi-driver \
    --cluster $EKS_CLUSTER_NAME \
    --region=$EKS_REGION \
    --service-account-role-arn arn:aws:iam::$ACCOUNT_ID:role/AmazonEKS_EBS_CSI_DriverRole --force

}

create_k8s_cluster $EKS_CLUSTER_NAME $EKS_REGION $EKS_VERSION

# check cluster status
eksctl utils describe-stacks \
  --region=$EKS_REGION \
  --cluster=$EKS_CLUSTER_NAME

# check ebs driver status
eksctl get addon \
    --name aws-ebs-csi-driver \
    --region=$EKS_REGION \
    --cluster $EKS_CLUSTER_NAME

# setup client
SVER=$(kubectl version --short | grep -e Server | grep -oP '(\d+\.){2}\d+')
asdf list kubectl | grep -qo $SVER || asdf install kubectl $SVER
asdf global kubectl $SVER

# setup new storage class
cat <<EOF > sc.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-sc
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
EOF

# install new storage class using functional driver
kubectl apply -f sc.yaml

# test new storage class before updating default
kubectl patch storageclass gp2 \
  -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
kubectl patch storageclass ebs-sc \
  -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'

Cleanup EKS

###
# IMPORTANT: It is important to delete K8S objects that indirectly prpvision cloud resources, e.g. 
#   * Services of type LoadBlaancer that created NLB or ELB (aka classic ELB)
#   * Ingress resources that created ALB (aka ELBv2)
#   * Perisistent sotrage (PVC) that created and mounted external EBS volumes
#####
eksctl delete cluster \
 --region $EKS_REGION \
 --name $EKS_CLUSTER_NAME

Deploy to Kubernetes using Terraform

You can use the tool kubectl to deploy Kubernetes objects or deploy fully baked Kubernetes applications with helm. Terraform can deploy Kubernetes objects or Helm charts. The advantage of using Terraform is that you can add automation on top of Kubernetes, similar to Helm charts, or add automation of the Helm chart config values. This could be useful, for things like initialize a object storage (S3, GCS, Azure Blob) or other cloud resource that is use in conjunction with Kubernetes objects.

Initializing Kubernetes provider

You need to initalize a Kubernetes (or Helm) provider with credentials needed to access the Kubernetes cluster. You can get the credentials using your cloud credentials from the cloud provider.

AKS

provider "azurerm" {
  features {}
}

data "azurerm_kubernetes_cluster" "aks" {
  name                = "my-aks-cluster"
  resource_group_name = "my-aks-rg"
}

provider "kubernetes" {
  host                   = data.azurerm_kubernetes_cluster.aks.kube_config.0.host
  client_certificate     = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.client_certificate)
  client_key             = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.client_key)
  cluster_ca_certificate = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.cluster_ca_certificate)
}

provider "helm" {
  kubernetes {
    host                   = data.azurerm_kubernetes_cluster.aks.kube_config.0.host
    client_certificate     = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.client_certificate)
    client_key             = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.client_key)
    cluster_ca_certificate = base64decode(data.azurerm_kubernetes_cluster.aks.kube_config.0.cluster_ca_certificate)
  }
}

GKE

provider "google" {
  project     = "my-gcp-project"
  region      = "us-central1"
}

data "google_container_cluster" "gke" {
  name     = "my-gke-cluster"
  location = "us-central1"
}

data "google_client_config" "default" {}

provider "kubernetes" {
  host                   = data.google_container_cluster.gke.endpoint
  cluster_ca_certificate = base64decode(data.google_container_cluster.gke.master_auth.0.cluster_ca_certificate)
  token                  = data.google_client_config.default.access_token
}

provider "helm" {
  kubernetes {
    host                   = data.google_container_cluster.gke.endpoint
    cluster_ca_certificate = base64decode(data.google_container_cluster.gke.master_auth.0.cluster_ca_certificate)
    token                  = data.google_client_config.default.access_token
  }
}

EKS

provider "aws" {
  region = "us-west-2"
}

data "aws_eks_cluster" "eks" {
  name = "my-eks-cluster"
}

provider "kubernetes" {
  host                   = data.aws_eks_cluster.eks.endpoint
  cluster_ca_certificate = base64decode(data.aws_eks_cluster.eks.certificate_authority.0.data)
  token                  = data.aws_eks_cluster.eks.token

  exec {
    api_version = "client.authentication.k8s.io/v1beta1"
    command     = "aws"
    args = [
      "eks",
      "get-token",
      "--cluster-name",
      data.aws_eks_cluster.cluster.name
    ]
  }
}

provider "helm" {
  kubernetes {
    host                   = data.aws_eks_cluster.eks.endpoint
    cluster_ca_certificate = base64decode(data.aws_eks_cluster.eks.certificate_authority.0.data)

    exec {
      api_version = "client.authentication.k8s.io/v1beta1"
      command     = "aws"
      args = [
        "eks",
        "get-token",
        "--cluster-name",
        data.aws_eks_cluster.cluster.name
      ]
    }
  }
}

Helm Chart Example

Once the helm provider is initalize, you can install helm charts.

# example kubernetes resource
resource "kubernetes_namespace" "nginx-ingress" {
  metadata {
    name = "ingress-nginx"
  }
}

# example helm resource
resource "helm_release" "nginx-ingress" {
  name       = "nginx-ingress"
  repository = "https://kubernetes.github.io/ingress-nginx"
  chart      = "ingress-nginx"
  namespace  = "ingress-nginx"

  values = [
    {
      "controller" = {
        "replicaCount" = 2
      }
    }
  ]
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment