[pmg-devel] [PATCH pmg-api] backup: restore: keep relevant subdirs in /etc/pmg for inotify

[Stoiko Ivanov <s.ivanov@proxmox.com>]

By wiping the subdirectories in /etc/pmg/, we lose the inotify
watchers upon restore (/etc/pmg itself and thus most configs are
currently handled by the keep_root flag to rmtree)
This can lead to inconsistencies after restoring for parts relying on
config in a subdirectory (e.g. /etc/pmg/pbs/pbs.conf).

This patch keeps a list of relevant config directories in place by
iterating over all entries and checking if they should be kept.

an alternative approach would be to simply reload pmgdaemon/pmgproxy
upon config-restore, but that feels more likely to miss some
(potentially future) service, expecting inotify to work.

Reported-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
Huge Thanks to Fiona for not only reporting, but also analyzing the issue!

 src/PMG/Backup.pm | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/PMG/Backup.pm b/src/PMG/Backup.pm
index a46167c..71193e9 100644
--- a/src/PMG/Backup.pm
+++ b/src/PMG/Backup.pm
@@ -8,7 +8,7 @@ use File::Path;
 use POSIX qw(strftime);
 
 use PVE::JSONSchema qw(get_standard_option);
-use PVE::Tools;
+use PVE::Tools qw(dir_glob_foreach);
 
 use PMG::pmgcfg;
 use PMG::AtomicFile;
@@ -306,8 +306,33 @@ sub pmg_restore {
 	    unlink "$dirname/config/etc/pmg/cluster.conf"; # never restore cluster config
 	    rmtree "$dirname/config/etc/pmg/master";
 
-	    # remove current config, but keep directory for INotify
-	    rmtree("/etc/pmg", { keep_root => 1 });
+	    # remove current config, but keep directories for INotify
+	    my $keep_dirs = {
+		acme => { accounts => 1 },
+		dkim => 1,
+		pbs => 1,
+		};
+
+	    my $remove_with_exclude;
+	    $remove_with_exclude = sub {
+		my ($dir, $excl) = @_;
+		dir_glob_foreach($dir, '.*', sub {
+		    my ($fn) = @_;
+		    return if $fn eq '.';
+		    return if $fn eq '..';
+		    if ( my $e = $excl->{$fn}) {
+			if (ref($e)) {
+			    $remove_with_exclude->("$dir/$fn", $e);
+			} else {
+			    rmtree("$dir/$fn", { keep_root => 1});
+			}
+		    } else {
+			rmtree("$dir/$fn");
+		    }
+		});
+	    };
+	    $remove_with_exclude->('/etc/pmg', $keep_dirs);
+
 	    # copy files
 	    system("cp -a $dirname/config/etc/pmg/* /etc/pmg/") == 0 ||
 		die "unable to restore system configuration: ERROR";
-- 
2.30.2