The internal DNS cannot resolve the url (https://rancher.rd.localhost/ping) because the Rancher`s DNS file (resolv.conf) can only resolve these addresses: cattle-system.svc.cluster.local svc.cluster.local cluster.local But your issue is before Rancher`s, if not even curl can resolve the address for rancher.rd.localhost (443) Rancher will not be able to resolve neither. Can you check if you can ping the URL from your agent node?

ping rancher.rd.localhost

also, try to telnet the IP/port from the agent node to the Rancher`s ingress IP?

telnet <ingress IP> 443

See if the IP is being resolved by ping and the packages are being delivered, if you don`t know how to read the result of ping, is expected something like this:

ping ip-xxx.sa-east-1.compute.internal
PING ip-xxx.sa-east-1.compute.internal (xxx) 56(84) bytes of data.
64 bytes from ip-xxx.sa-east-1.compute.internal (xxx): icmp_seq=1 ttl=64 time=0.031 ms
64 bytes from ip-xxx.sa-east-1.compute.internal (xxx): icmp_seq=2 ttl=64 time=0.042 ms
^C
--- ip-xxx.sa-east-1.compute.internal ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1035ms
rtt min/avg/max/mdev = 0.031/0.036/0.042/0.005 ms

At the end of the day @delightful-kitchen-63100, you were right. Even though

nslookup

was resolving the correct IP address;

curl

apparently still was not. After using the IP address of the host instead of the name, everything worked. Since this is a local dev deployment, I'm satisfied with using IPs instead of DNS. Thanks for the insight.

@adamant-traffic-5372 that`s great. Glad that I could help 🙂