Using private Network without 10.0.0.0/8

[JanKgh]

Hi all,

are there any howtos or extended documentation for using predefined private networks with nat gateway.
I'm not able to use ip adresses from 10.0.0.0/8 because they are used in many Subnets onprem.

My goal is to create a privat, not public reachable kubernetes cluster in hcloud with ip adresses from 172.24.0.0/16.

I create a network 172.24.0.0/15 and a subnet 172.25.0.0/16, there are the nat gateway at 172.25.0.1. In hcloud network are a default route to 172.25.0.1.

I try following:

source = "github.com/kube-hetzner/terraform-hcloud-kube-hetzner"

...

 existing_network_id = [${network.id}]
 
   network_ipv4_cidr = "172.24.0.0/16"
   cluster_ipv4_cidr = "172.24.96.0/20"
   service_ipv4_cidr = "172.24.112.0/20"
   cluster_dns_ipv4 = "172.24.112.10"
   control_plane_nodepools = [
     {
       name        = "cp",
       server_type = "cx22",
       location    = "fsn1",
       labels      = [],
       taints      = [],
       count       = 1,
       disable_ipv4 = true,
       disable_ipv6 = true,
     },
   ]
 
   agent_nodepools = [
     {
       name        = "agent",
       server_type = "cpx21",
       location    = "fsn1",
       labels      = [],
       taints      = [],
       count       = 1,
       disable_ipv4 = true,
       disable_ipv6 = true,
     },
   ]
....

After terraform apply there two errors.

 Error: invalid input in fields 'ip', 'dns_ptr_ip' (invalid_input, ba73286cd7aad31bcf11dde3a7b23c57): [ip => [field contains invalid value: is not a public or non-CGNAT IP address] dns_ptr_ip => [field contains invalid value: is not a public or non-CGNAT IP address]]
│

and

Error: invalid input in fields 'ip', 'dns_ptr_ip' (invalid_input, d4de4b3830c06b429a538f234da384d3): [ip => [field contains invalid value: is not a public or non-CGNAT IP address] dns_ptr_ip => [field contains invalid value: is not a public or non-CGNAT IP address]]
│

I understand, no rdns with private IP, yes i don't need it. How can i disable it.

Are there any possibilities to go this way or is it impossible?

thx
jk

[JanKgh]

ok, found #1685 (fix: host module should not create rdns if instances have only private ips.)