Ensure that the Prometheus port is added to the whitelisted ports for incoming traffic in the security group. This can be done with the following Terraform code:
node_security_group_additional_rules = {
prometheus_9090_webhook = {
description = "Cluster API to Prometheus Port 9090 webhook"
protocol = "tcp"
from_port = 9090
to_port = 9090
type = "ingress"
source_cluster_security_group = true
}
}