Creating SKS Cluster

Mon, 01 Jan 0001 00:00:00 +0000

SKS (Scalable Kubernetes Service) is the Exoscale-managed cluster. To deploy an SKS cluster, we can use one of the following tools:

Whatever tool we use, it creates the following resources:

a Security Group and some associated rules
an SKS cluster
a Nodepool

We will go through the details of each approach, so you can select the one you prefer. But first, you need to create an account and get free credits to follow this workshop.

Using exo CLI

Mon, 01 Jan 0001 00:00:00 +0000

The shell script sks.sh, detailed below, creates the following Exoscale resources:

a security group
security group rules
a SKS cluster
a node pool for the SKS cluster

[!WARNING] This script allows the creation of an SKS cluster easily. This is fine for a workshop, but it must not be used to create a production cluster

#!/usr/bin/env bash
# set -euo pipefail

CURRENT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" &> /dev/null && pwd)

function usage {
 echo $1
 echo "usage: sks.sh -n NAME [-s SIZE] [-t TYPE] [-l LEVEL] [-z ZONE] [-p NETWORK] [-v VERSION]"
 exit 1
}

# Creation of a Security Group
function create-sg {
 exo compute security-group create sks-${NAME}

 # Creating of the rules related to the security group

 exo compute security-group rule add sks-${NAME} \
 --description "NodePort services" \
 --protocol tcp \
 --network 0.0.0.0/0 \
 --port 30000-32767

 exo compute security-group rule add sks-${NAME} \
 --description "SKS kubelet" \
 --protocol tcp \
 --port 10250-10251 \
 --security-group sks-${NAME}

 exo compute security-group rule add sks-${NAME} \
 --description "Prometheus metrics" \
 --protocol tcp \
 --port 9100 \
 --security-group sks-${NAME}

 if [ "${NETWORK}" = "cilium" ]; then
 exo compute security-group rule add sks-${NAME} \
 --description "Cilium VXLAN" \
 --protocol udp \
 --port 8472 \
 --security-group sks-${NAME}

 exo compute security-group rule add sks-${NAME} \
 --description "Cilium Health-check ICMP" \
 --protocol icmp \
 --icmp-code 0 \
 --icmp-type 8 \
 --security-group sks-${NAME}

 exo compute security-group rule add sks-${NAME} \
 --description "Cilium Health-check TCP" \
 --protocol tcp \
 --port 4240 \
 --security-group sks-${NAME}
 else # Calico
 exo compute security-group rule add sks-${NAME} \
 --description "Calico traffic" \
 --protocol udp \
 --port 4789 \
 --security-group sks-${NAME}
 fi
}

# Creation of the cluster
function create-cluster {
 exo compute sks create $NAME \
 --zone ${ZONE} \
 --auto-upgrade \
 --cni ${NETWORK} \
 --exoscale-csi \
 --service-level ${LEVEL} \
 --kubernetes-version ${VERSION} \
 --nodepool-name sks-${NAME} \
 --nodepool-instance-type standard.${TYPE} \
 --nodepool-size ${SIZE} \
 --nodepool-disk-size 50 \
 --nodepool-security-group sks-${NAME}
}

# Get the kubeconfig file and modify it a bit
function get-kubeconfig {
 # Get kubeconfig file
 exo compute sks kubeconfig $NAME cluster-admin -z $ZONE > $CURRENT_DIR/sks-$NAME.kubeconfig

 # Rename cluster-admin user
 gsed -i "s/cluster-admin/cluster-admin-$NAME/g" "$CURRENT_DIR/sks-$NAME.kubeconfig"

 # Rename the context
 CONTEXT=$(KUBECONFIG=$CURRENT_DIR/sks-$NAME.kubeconfig kubectl config current-context)
 KUBECONFIG=$CURRENT_DIR/sks-$NAME.kubeconfig kubectl config rename-context $CONTEXT $NAME

 echo "Use the cluster:"
 echo $CURRENT_DIR
 echo "export KUBECONFIG=$CURRENT_DIR/sks-$NAME.kubeconfig"
}

# Delete nodepool
function delete-nodepool {
 for np in $(exo compute sks nodepool list -O json | jq -r ".[].id"); do
 exo compute sks nodepool delete $NAME $np -f -z $ZONE;
 done
}

# Delete cluster
function delete-cluster {
 exo compute sks delete -f -z $ZONE $NAME

 # Remove kubeconfig file
 rm $CURRENT_DIR/sks-$NAME.kubeconfig
}

# Delete security groups
function delete-sg {
 # Delete the rules of the associated security group
 for rule in $(exo compute security-group show sks-$NAME -O json | jq -r ".ingress_rules[].id"); do
 exo compute security-group rule delete -f sks-$NAME $rule;
 done

 # Delete associated security group
 exo compute security-group delete -f sks-$NAME
}

# Argument parsing
while getopts "dt:s:n:l:p:z:v:" option; do
 case "${option}" in
 d)
 ACTION="delete"
 ;;
 t)
 TYPE=${OPTARG}
 ;;
 s)
 SIZE=${OPTARG}
 ;;
 l)
 LEVEL=${OPTARG}
 ;;
 n)
 NAME=${OPTARG}
 ;;
 p)
 NETWORK=${OPTARG}
 ;;
 z)
 ZONE=${OPTARG}
 ;;
 v)
 VERSION=${OPTARG}
 ;;
 *)
 usage
 ;;
 esac
done

# Make sure the name is provided for create and delete actions
if [ -z "$NAME" ]; then
 usage "Cluster name must be provided though the -n flag"
fi

# Default values to params
TYPE=${TYPE:-medium}
SIZE=${SIZE:-"3"}
LEVEL=${LEVEL:-"starter"}
ZONE=${ZONE:-"ch-gva-2"}
NETWORK=${NETWORK:-"cilium"}
VERSION=${VERSION:-"latest"}

# Get action to perform
ACTION=${ACTION:-"create"}

# Handling deletion
if [ "$ACTION" = "delete" ]; then
 delete-nodepool
 delete-sg
 delete-cluster
 exit 0
fi

# Handling creation
create-sg
create-cluster
get-kubeconfig

This script also generates a kubeconfig file to access the cluster API Server.

Exo-Cli on Exoscale Academy

Creating SKS Cluster

Using exo CLI