[PATCH cluster v4 5/8] api: join info: add totem timeout warning message and level

["Michael Köppl" <m.koeppl@proxmox.com>]

The warning message and level based on the calculated membership
recovery timeout provide additional information to users on whether
the token coefficient used in their Corosync cluster could be
optimized, or if a change is (strongly) recommended. This lets users
make an informed decision about potentially reducing the coefficient
before adding another node to their cluster.

The `warnings` property is defined as an object with `message`, `level`,
and `type` fields to be expandable for additional errors or warnings in
the future and also allow for easily distinguishing between different
kinds of warnings and their levels.

Signed-off-by: Michael Köppl <m.koeppl@proxmox.com>
---
 src/PVE/API2/ClusterConfig.pm | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/PVE/API2/ClusterConfig.pm b/src/PVE/API2/ClusterConfig.pm
index bbed40e..2172ab1 100644
--- a/src/PVE/API2/ClusterConfig.pm
+++ b/src/PVE/API2/ClusterConfig.pm
@@ -535,6 +535,7 @@ __PACKAGE__->register_method({
         check => ['perm', '/', ['Sys.Audit']],
     },
     method => 'GET',
+    protected => 1,
     description => "Get information needed to join this cluster over the connected node.",
     parameters => {
         additionalProperties => 0,
@@ -571,6 +572,19 @@ __PACKAGE__->register_method({
             preferred_node => get_standard_option('pve-node'),
             totem => { type => 'object' },
             config_digest => { type => 'string' },
+            warnings => {
+                type => 'array',
+                optional => 1,
+                items => {
+                    type => 'object',
+                    additionalProperties => 1,
+                    properties => {
+                        type => { type => 'string' },
+                        level => { type => 'string' },
+                        message => { type => 'string' },
+                    },
+                },
+            },
         },
     },
     code => sub {
@@ -599,12 +613,19 @@ __PACKAGE__->register_method({
             $node->{pve_addr} = scalar(PVE::Cluster::remote_node_ip($name));
         }
 
+        my $total_timeout_secs = PVE::Corosync::calculate_membership_recovery_timeout();
+        my ($level, $msg) =
+            PVE::Corosync::get_membership_recovery_timeout_warning($total_timeout_secs);
+
         my $res = {
             nodelist => [values %$nodelist],
             preferred_node => $nodename,
             totem => $totem_cfg,
             config_digest => $corosync_config_digest,
         };
+        $res->{warnings} =
+            [{ type => 'corosync-membership-recovery-timeout', level => $level, message => $msg }]
+            if defined($msg);
 
         return $res;
     },
-- 
2.47.3