[pve-devel] [PATCH manager 1/1] pve6to7: check for containers not supporting pure cgroupv2

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

Ordered as much as possible to exit early, still might take quite some
time on systems with many containers (which do support cgroupv2).

needs a versioned bump on pve-container

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
 PVE/CLI/pve6to7.pm | 68 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/PVE/CLI/pve6to7.pm b/PVE/CLI/pve6to7.pm
index 60edac11..3d7c67bd 100644
--- a/PVE/CLI/pve6to7.pm
+++ b/PVE/CLI/pve6to7.pm
@@ -23,6 +23,9 @@ use PVE::Tools qw(run_command split_list);
 use PVE::QemuConfig;
 use PVE::QemuServer;
 use PVE::VZDump::Common;
+use PVE::LXC;
+use PVE::LXC::Config;
+use PVE::LXC::Setup;
 
 use Term::ANSIColor;
 
@@ -890,6 +893,70 @@ sub check_storage_content {
 	log_pass("no problems found");
     }
 }
+sub check_containers_cgroup_compat {
+
+    my $kernel_cli = PVE::Tools::file_get_contents('/proc/cmdline');
+    if ($kernel_cli =~ /systemd.unified_cgroup_hierarchy=0/){
+	log_skip("System explicitly configured for legacy hybrid cgroup hierarchy.");
+	return;
+    }
+
+    my $cts = eval { PVE::API2::LXC->vmlist({ node => $nodename }) };
+    if ($@) {
+	log_warn("Failed to retrieve information about this node's CTs - $@");
+	return;
+    }
+
+    if (!defined($cts) || !scalar(@$cts)) {
+	log_skip("No containers on node detected.");
+	return;
+    }
+    my @running_vmids = map { $_->{status} eq 'running' ? $_->{vmid} : () } @$cts;
+    my @offline_vmids = map { $_->{status} ne 'running' ? $_->{vmid} : () } @$cts;
+
+    my $legacy_container=0;
+
+    for my $ctid (@running_vmids) {
+	my $pid = eval { PVE::LXC::find_lxc_pid($ctid) };
+	if (my $err = $@) {
+	    log_warn("Failed to get PID for running CT $ctid - $err");
+	    next;
+	}
+	my $rootdir = "/proc/$pid/root";
+	my $conf = PVE::LXC::Config->load_config($ctid);
+	my $lxc_setup = PVE::LXC::Setup->new($conf, $rootdir);
+	if (!$lxc_setup->unified_cgroupv2_support()) {
+	    log_warn("CT $ctid does not support running in a unified cgroup v2 layout - either " .
+		"upgrade it or set systemd.unified_cgroup_hierarchy=0 in the kernel cmdline - "  .
+		"skipping further checks");
+	    return;
+	}
+    }
+
+    my $storage_cfg = PVE::Storage::config();
+    for my $ctid (@offline_vmids) {
+	my ($conf, $rootdir, $lxc_setup);
+	eval {
+	    $conf = PVE::LXC::Config->load_config($ctid);
+	    $rootdir = PVE::LXC::mount_all($ctid, $storage_cfg, $conf);
+	    $lxc_setup = PVE::LXC::Setup->new($conf, $rootdir);
+	};
+	if (my $err = $@) {
+	    log_warn("Failed to load config and mount CT $ctid - $err");
+	    eval { PVE::LXC::umount_all($ctid, $storage_cfg, $conf) };
+	    next;
+	}
+	if (!$lxc_setup->unified_cgroupv2_support()) {
+	    log_warn("CT $ctid does not support running in a unified cgroup v2 layout - either " .
+		"upgrade it or set systemd.unified_cgroup_hierarchy=0 in the kernel cmdline - "  .
+		"skipping further checks");
+	    eval { PVE::LXC::umount_all($ctid, $storage_cfg, $conf) };
+	    last;
+	}
+
+	eval { PVE::LXC::umount_all($ctid, $storage_cfg, $conf) };
+    }
+};
 
 sub check_misc {
     print_header("MISCELLANEOUS CHECKS");
@@ -986,6 +1053,7 @@ sub check_misc {
     check_custom_pool_roles();
     check_description_lengths();
     check_storage_content();
+    check_containers_cgroup_compat();
 }
 
 __PACKAGE__->register_method ({
-- 
2.30.2