[pve-devel] [PATCH installer 1/3] run env: fix dhcp-set hostname containing local domain

[Christoph Heiss]

According to RFC 2132 section 3.14 [0], the hostname _can_ also include the
local domain name. Strip the suffix it before storing it into the
runtime environment.

Reported on the community forum [1].

[0] https://www.rfc-editor.org/rfc/rfc2132#section-3.14
[1] https://forum.proxmox.com/threads/auto-install-fetching-fqdn-through-dhcp-does-not-set-search-domain-correctly.168369/

Fixes: bda1cdf ("run env: retrieve and store hostname from DHCP lease if available")
Signed-off-by: Christoph Heiss <c.heiss at proxmox.com>
---
 Proxmox/Install/RunEnv.pm |  7 ++++++-
 Proxmox/Sys/Net.pm        | 12 ++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Proxmox/Install/RunEnv.pm b/Proxmox/Install/RunEnv.pm
index cdd7992..ce89346 100644
--- a/Proxmox/Install/RunEnv.pm
+++ b/Proxmox/Install/RunEnv.pm
@@ -292,7 +292,12 @@ sub query_installation_environment : prototype() {
     };
 
     # avoid serializing out null or an empty string, that can trip up the UIs
-    if (my $fqdn = Proxmox::Sys::Net::get_dhcp_fqdn()) {
+    if (my $fqdn = Proxmox::Sys::Net::get_dhcp_hostname()) {
+        if (defined($output->{network}->{dns}->{domain})) {
+            # strip domain name suffix, if possible
+            $fqdn =~ s/\.$output->{network}->{dns}->{domain}//;
+        }
+
         $output->{network}->{hostname} = $fqdn;
     }
 
diff --git a/Proxmox/Sys/Net.pm b/Proxmox/Sys/Net.pm
index 38aab0e..6fe99ec 100644
--- a/Proxmox/Sys/Net.pm
+++ b/Proxmox/Sys/Net.pm
@@ -204,12 +204,16 @@ sub udevadm_netdev_details {
     return $result;
 }
 
-# Tries to detect the FQDN hostname for this system via DHCP, if available.
+# Tries to detect the hostname for this system given via DHCP, if available.
+# The hostname _might_ also include the local domain name, depending on the
+# concrete DHCP server implementation.
+#
+# DHCP servers can set option 12 to inform the client about it's hostname [0].
+# dhclient dumps all options set by the DHCP server it in lease file, so just
+# read it from there.
 #
-# DHCP server can set option 12 to inform the client about it's hostname [0]. dhclient dumps all
-# options set by the DHCP server it in lease file, so just read it from there.
 # [0] RFC 2132, section 3.14
-sub get_dhcp_fqdn : prototype() {
+sub get_dhcp_hostname : prototype() {
     my $leasefile = '/var/lib/dhcp/dhclient.leases';
     return if !-f $leasefile;
 
-- 
2.49.0