k8s_russian_roulette_scaling.sh

#!/bin/sh
#
# this script randomly scales 1 deployment per namespace per cluster (for demo purposes)
#
# 2019 Martijn Smit <msmit@vmware.com>

cluster_list=("k8s-cluster-1" "k8s-cluster-2")

for cluster in "${cluster_list[@]}"
do
    # switch to a cluster
    kubectl config use-context $cluster
    # get all namespaces in that cluster, exclude the system ones
    namespace_list=(`kubectl get namespaces | grep -v "kube-" | grep -v default | grep -v "pks-" | grep -v NAME | awk -F " " '{print $1}'`)
    # loop through namespaces and get the deployments
    for namespace in "${namespace_list[@]}"
    do
        # get a list of deployments
        deployment_list=(`kubectl get deployments -n $namespace | grep -v NAME | awk -F " " '{print $1}'`)
        # grab a number between 1 and 5 for the new scale
        new_scale=`shuf -i 1-5 -n 1`
        # pick a random deployment
        deployment_list_size=${#deployment_list[@]}
        deployment_list_index=$(($RANDOM % $deployment_list_size))
        deployment="${deployment_list[$deployment_list_index]}"
        # scale deployment!
        kubectl scale --replicas=$new_scale deployment/$deployment -n $namespace
        echo "Scaled $namespace/$deployment to $new_scale replicas"
    done
done