From 3e546c5ada47da8434bb58d27a3aa7d9823e7fa4 Mon Sep 17 00:00:00 2001
From: Leo Nunner <l.nunner@proxmox.com>
Date: Tue, 23 May 2023 09:14:19 +0200
Subject: [PATCH] cloudinit: pass through hostname via fqdn field

If no FQDN is provided, we simply set it to the current hostname. This
ensures that the hostname *really* gets set, since we encountered an
issue on Fedora and CentOS based systems where no hostname got set at
all.

When there's no FQDN set in the cloudinit config, this leads to the
following entry:

    127.0.1.1 <hostname> <hostname>

Which doesn't seem to cause any issues.

Tested on:
 - Ubuntu 23.04
 - CentOS 8
 - Fedora 38
 - Debian 11
 - SUSE 15.4

Signed-off-by: Leo Nunner <l.nunner@proxmox.com>
---
 PVE/QemuServer/Cloudinit.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/PVE/QemuServer/Cloudinit.pm b/PVE/QemuServer/Cloudinit.pm
index 10962b50..cd5cc242 100644
--- a/PVE/QemuServer/Cloudinit.pm
+++ b/PVE/QemuServer/Cloudinit.pm
@@ -87,6 +87,8 @@ sub get_hostname_fqdn {
 	$hostname =~ s/\..*$//;
     } elsif (my $search = $conf->{searchdomain}) {
 	$fqdn = "$hostname.$search";
+    } else {
+	$fqdn = $hostname;
     }
     return ($hostname, $fqdn);
 }
@@ -120,7 +122,7 @@ sub cloudinit_userdata {
 
     $content .= "hostname: $hostname\n";
     $content .= "manage_etc_hosts: true\n";
-    $content .= "fqdn: $fqdn\n" if defined($fqdn);
+    $content .= "fqdn: $fqdn\n";
 
     my $username = $conf->{ciuser};
     my $password = $conf->{cipassword};