package elb
import (
"dagger.io/aws"
)
// Returns a non-taken rule priority (randomized)
#RandomRulePriority: {
// AWS Config
config: aws.#Config
// ListenerArn
listenerArn: string
// Optional vhost for reusing priorities
vhost?: string
// exported priority
out: string
aws.#Script & {
files: {
"/inputs/listenerArn": listenerArn
if vhost != _|_ {
"/inputs/vhost": vhost
}
export: "/priority"
//FIXME: The code below can end up not finding an available prio
// Better to exclude the existing allocated priorities from the random sequence
code: #"""
if [ -s /inputs/vhost ]; then
# We passed a vhost as input, try to recycle priority from previously allocated vhost
vhost="$(cat /inputs/vhost)"
priority=$(aws elbv2 describe-rules \
--listener-arn "$(cat /inputs/listenerArn)" | \
jq -r --arg vhost "$vhost" '.Rules[] | select(.Conditions[].HostHeaderConfig.Values[] == $vhost) | .Priority')
if [ -n "${priority}" ]; then
echo -n "${priority}" > /priority
exit 0
fi
# Grab a priority random from 1-50k and check if available, retry 10 times if none available
priority=0
for i in {1..10}
do
p=$(shuf -i 1-50000 -n 1)
# Find the next priority available that we can allocate
aws elbv2 describe-rules \
--listener-arn "$(cat /inputs/listenerArn)" \
| jq -e "select(.Rules[].Priority == \"${p}\") | true" && continue
priority="${p}"
break
done
if [ "${priority}" -lt 1 ]; then
echo "Error: cannot determine a Rule priority"
exit 1
"""#