kubectl-scaleall - Scale most deployments and stateful sets up or down

kubectl-scaleall

#! /bin/sh

# kubectl-scaleall - Scale most deployments and stateful sets up or down
# Copyright (C) 2023 Matous Jan Fialka, <https://mjf.cz/>
# Released under the terms of the "MIT" license

PROGRAM="${0##*/}"
VERSION='0.1.4'
LICENSE='MIT'
AUTHORS='2022 Matous Jan Fialka, <https://mjf.cz/>'

# HELPERS

proc() {
	local n=$1
	local a=''
	shift 1
	for a in $@; do
		if [ $no_color_out ]; then
			printf -- 'PROC[%05d] %s: prosessing '\''%s'\''\n' $n "$PROGRAM" "$a"
		else
			printf -- '\x1b[32mPROC\x1b[0m[%05d] \x1b[35m%s\x1b[0m: prosessing '\''\x1b[34;47;7m%s\x1b[0m'\''\n' $n "$PROGRAM" "$a"
		fi
	done
}

info() {
	local n=$1
	shift 1
	if [ $no_color_out ]; then
		printf -- 'INFO[%05d] %s: %s\n' $n "$PROGRAM" "$1"
	else
		printf -- '\x1b[36mINFO\x1b[0m[%05d] \x1b[35m%s\x1b[0m: %s\n' $n "$PROGRAM" "$1"
	fi
}

warn() {
	local n=$1
	shift 1
	if [ $no_color_err ]; then
		printf -- 'WARN[%05d] %s: %s\n' $n "$PROGRAM" "$1" >&2
	else
		printf -- '\x1b[33mWARN\x1b[0m[%05d] \x1b[35m%s\x1b[0m: \x1b[33m%s\x1b[0m\n' $n "$PROGRAM" "$1" >&2
	fi
}

fail() {
	local n=$1
	shift 1
	if [ $no_color_err ]; then
		printf -- 'FAIL[%05d] %s: %s\n' $n "$PROGRAM" "$2" >&2
	else
		printf -- '\x1b[31;47;7mFAIL\x1b[0m[%05d] \x1b[35m%s\x1b[0m: \x1b[31;47;7m%s\x1b[0m\n' $n "$PROGRAM" "$2" >&2
	fi
	exit ${1:-1}
}

# MAIN

no_color_out=$NO_COLOR
if ! [ -t 1 ]; then
	no_color_out='yes'
fi

no_color_err=$NO_COLOR
if ! [ -t 2 ]; then
	no_color_err='yes'
fi

replicas=${1:-1}

info 0 "rescaling all deployments and stateful sets in all namespaces to $replicas replicas"
info 10000 "getting list of namespaces"

namespaces=$(
	kubectl get namespaces 2>/dev/null |
	sed '1d' |
	awk '{print$1}'
)

error=$?
if [ $error -ne 0 ]; then
	fail 10001 $error "could not get list of namespaces"
fi

i=19999
for namespace in $namespaces; do
	let i++

	info $i "getting list of deployments in namespace '$namespace'"

	if [ "$namespace" = 'kube-system' -a $replicas -eq 0 ]; then
		warn $i "skipped system namespace 'kube-system' (unsafe to rescale)"
		continue
	fi

	deployments=$(
		kubectl --namespace "$namespace" get deployments 2>/dev/null |
		sed '1d' |
		awk '{print$1}'
	)

	error=$?
	if [ $error -ne 0 -o ${#deployments} -eq 0 ]; then
		warn $i "cannot get list of deployments in namespace '$namespace' (skipped)"
		continue
	fi

	info $i "rescaling deployments in namespace '$namespace'"
	proc $i "$deployments"

	kubectl scale deployment \
		--namespace $namespace \
		--replicas $replicas \
		$deployments &>/dev/null

	error=$?
	if [ $error -ne 0 ]; then
		warn $i "could not rescale deployments in namespace '$namespace' (review suggested)"
	else
		info $i "deployments in namespace '$namespace' rescaled to $replicas replicas"
	fi
done

i=29999
for namespace in $namespaces; do
	let i++

	info $i "getting list of stateful sets in namespace '$namespace'"

	if [ "$namespace" = 'kube-system' -a $replicas -eq 0 ]; then
		warn $i "skipped system namespace 'kube-system' (unsafe to rescale)"
		continue
	fi

	statefulsets=$(
		kubectl --namespace "$namespace" get statefulsets 2>/dev/null |
		sed '1d' |
		awk '{print$1}'
	)

	error=$?
	if [ $error -ne 0 -o ${#statefulsets} -eq 0 ]; then
		warn $i "cannot get list of stateful sets in namespace '$namespace' (skipped)"
		continue
	fi

	info $i "rescaling stateful sets in namespace '$namespace'"
	proc $i "$statefulsets"

	kubectl scale statefulset \
		--namespace $namespace \
		--replicas $replicas \
		$statefulsets &>/dev/null

	error=$?
	if [ $error -ne 0 ]; then
		warn $i "could not rescale stateful sets in namespace '$namespace' (review suggested)"
	else
		info $i "stateful sets in namespace '$namespace' rescaled to $replicas replicas"
	fi
done

info 0 'rescaling done (review of overall cluster state suggested)'

# vi:ft=sh:nowrap