pvecm addnode: ensure ring address isn't already used by cluster

If someone enters the wrong address by accident when adding a node it
may cause havoc in the cluster (meaning a reset of the whole cluster
when HA is used, may even happen more often during the recovery
tries. Also a whole lot of problems get triggered in gneral, even
witouth HA).

Further, user get into a hard to repair situation where a layman may
not be able to fix it by hand even when given directions by an
experienced user.

This is a really bad outcome for such a small and easy to make
mistake, so just make a small check and assert that the requested IPs
are not used by any node on any ring in the cluster configuration.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/data/PVE/CLI/pvecm.pm b/data/PVE/CLI/pvecm.pm
index c3f790567d7e0f9526504eb2e9a59e2439efedd1..1c5d863d5757d6054a73c7c53555ed35a9014804 100755 (executable)
--- a/data/PVE/CLI/pvecm.pm
+++ b/data/PVE/CLI/pvecm.pm
@@ -316,6 +316,22 @@ __PACKAGE__->register_method ({
 
        my $name = $param->{node};
 
+       # ensure we do not reuse an address, that can crash the whole cluster!
+       my $check_duplicate_addr = sub {
+           my $addr = shift;
+           return if !defined($addr);
+
+           while (my ($k, $v) = each %$nodelist) {
+               next if $k eq $name; # allows re-adding a node if force is set
+               if ($v->{ring0_addr} eq $addr || ($v->{ring1_addr} && $v->{ring1_addr} eq $addr)) {
+                   die "corosync: address '$addr' already defined by node '$k'\n";
+               }
+           }
+       };
+
+       &$check_duplicate_addr($param->{ring0_addr});
+       &$check_duplicate_addr($param->{ring1_addr});
+
        $param->{ring0_addr} = $name if !$param->{ring0_addr};
 
        die " ring1_addr needs a configured ring 1 interface!\n"