[PATCH manager v3 38/39] api: notification: reject matchers with expression if not supported by all nodes

[Lukas Wagner <l.wagner@proxmox.com>]

The new matcher UI will automatically migrate any existing matcher to
one with an 'expression', and new matchers will also only use this new
parameter. If any of the cluster nodes uses a version of pve-manager
that does not yet support the new parameter, any matcher written by an
updated node will break notifications on the older nodes.

To avoid this, on create/update, we now reject matchers with an
'expression' parameter if any of the online cluster nodes is still
running on a too old version of pve-manager. While this still leaves the
possibility of an outdated, offline node coming back online and then
failing to parse the migrated notification config, it would be
unreasonable to disallow editing the notification configuration if any
node is offline.

Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>
---

Notes:
    New in v3.
    
    Note to maintainers: Please change the version guard to the version
    of pve-manager that actually includes the change.

 PVE/API2/Cluster/Notifications.pm | 32 +++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/PVE/API2/Cluster/Notifications.pm b/PVE/API2/Cluster/Notifications.pm
index bd3c86cc..fd2f695b 100644
--- a/PVE/API2/Cluster/Notifications.pm
+++ b/PVE/API2/Cluster/Notifications.pm
@@ -6,11 +6,13 @@ use strict;
 use Storable qw(dclone);
 use JSON;
 
+use PVE::Cluster;
 use PVE::Exception qw(raise_param_exc);
 use PVE::Tools qw(extract_param);
 use PVE::JSONSchema qw(get_standard_option);
 use PVE::RESTHandler;
 use PVE::Notify;
+use PVE::SafeSyslog;
 
 use base qw(PVE::RESTHandler);
 
@@ -56,6 +58,23 @@ sub raise_api_error {
     die $exc;
 }
 
+my $matcher_expressions_version = "9.2.21";
+my $matcher_expressions_version_array = [9, 2, 21];
+
+my sub matcher_expressions_supported {
+    my $version_info = PVE::Cluster::get_node_kv('version-info');
+    for my $node (sort keys $version_info->%*) {
+        my $node_info = eval { JSON::decode_json($version_info->{$node}); };
+        if (my $err = $@) { # warn, but continue
+            syslog('warn', "cannot parse version info for $node as JSON - $err");
+        } elsif (!PVE::Cluster::pvecfg_min_version($node_info->{version}, @$matcher_expressions_version_array)) {
+            return 0;
+        }
+    }
+
+    return 1;
+}
+
 __PACKAGE__->register_method({
     name => 'index',
     path => '',
@@ -1660,10 +1679,17 @@ __PACKAGE__->register_method({
     code => sub {
         my ($param) = @_;
 
+        # FIXME: MAJOR VERSION: This check can be dropped at the next major version bump.
+        if (defined($param->{expression}) && !matcher_expressions_supported()) {
+            die "At least one cluster node does not support matcher expressions."
+                . " Please upgrade pve-manager to at least $matcher_expressions_version.";
+        }
+
         eval {
             PVE::Notify::lock_config(sub {
                 my $config = PVE::Notify::read_config();
 
+
                 $config->add_matcher($param);
 
                 PVE::Notify::write_config($config);
@@ -1708,6 +1734,12 @@ __PACKAGE__->register_method({
         my $digest = extract_param($param, 'digest');
         my $delete = extract_param($param, 'delete');
 
+        # FIXME: MAJOR VERSION: This check can be dropped at the next major version bump.
+        if (defined($param->{expression}) && !matcher_expressions_supported()) {
+            die "At least one cluster node does not support matcher expressions."
+                . " Please upgrade pve-manager to at least $matcher_expressions_version.";
+        }
+
         eval {
             PVE::Notify::lock_config(sub {
                 my $config = PVE::Notify::read_config();
-- 
2.47.3