[pve-devel] [PATCH container] Close #1234: pct: implement rescan

[Alwin Antreich]

This patch implements the same feature as already exists for qm
'rescan'. With options for updating the disksize or the unused disks
only.

Signed-off-by: Alwin Antreich <a.antreich at proxmox.com>
---
Sure some methods can be migrated into the guest-common. Comments appreciated.

 src/PVE/CLI/pct.pm |  44 ++++++++++++++++
 src/PVE/LXC.pm     | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 193 insertions(+)

diff --git a/src/PVE/CLI/pct.pm b/src/PVE/CLI/pct.pm
index 6296d6f..36e3fcf 100755
--- a/src/PVE/CLI/pct.pm
+++ b/src/PVE/CLI/pct.pm
@@ -461,6 +461,49 @@ sub create_file {
     return $fd;
 }
 
+__PACKAGE__->register_method ({
+    name => 'rescan',
+    path => 'rescan',
+    method => 'POST',
+    description => "Rescan all storages and update disk sizes and unused disk images.",
+    parameters => {
+	additionalProperties => 0,
+	properties => {
+	    vmid => get_standard_option('pve-vmid', {
+		optional => 1,
+		completion => \&PVE::LXC::complete_ctid,
+	    }),
+	    dryrun => {
+		type => 'boolean',
+		optional => 1,
+		default => 0,
+		description => 'Do not actually write changes out to conifg.',
+	    },
+	    unusedOnly => {
+		type => 'boolean',
+		optional => 1,
+		default => 0,
+		description => 'Add only unsued disk(s) to the config.',
+	    },
+	    disksizeOnly => {
+		type => 'boolean',
+		optional => 1,
+		default => 0,
+		description => 'Only update the disk size in the conifg.',
+	    },
+	},
+    },
+    returns => { type => 'null'},
+    code => sub {
+	my ($param) = @_;
+
+	print "NOTE: running in dry-run mode, won't write changes out!\n" if $param->{dryrun};
+
+	PVE::LXC::rescan($param->{vmid}, 0, $param);
+
+	return undef;
+    }});
+
 __PACKAGE__->register_method({
     name => 'pull',
     path => 'pull',
@@ -774,6 +817,7 @@ our $cmddef = {
     pull => [ __PACKAGE__, 'pull', ['vmid', 'path', 'destination']],
 
     df => [ __PACKAGE__, 'df', ['vmid']],
+    rescan  => [ __PACKAGE__, 'rescan', []],
 
     destroy => [ 'PVE::API2::LXC', 'destroy_vm', ['vmid'], 
 		 { node => $nodename }, $upid_exit ],
diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index 0b57ae9..e78128a 100644
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -1538,6 +1538,155 @@ sub create_disks {
     return $vollist;
 }
 
+sub update_disksize {
+    my ($vmid, $conf, $volid_hash) = @_;
+
+    my $changes;
+
+    my $update_mp = sub {
+	my ($key, $mp, @param) = @_;
+	my $size = $volid_hash->{$mp->{volume}}->{size};
+
+	if ($size != $mp->{size}) {
+	    $changes = 1;
+	    $mp->{size} = $size;
+	}
+
+	my $skip = $key eq 'rootfs' ? 1 : 0;
+	$conf->{$key} = PVE::LXC::Config->print_ct_mountpoint($mp, $skip);
+    };
+
+    PVE::LXC::Config->foreach_mountpoint($conf, $update_mp);
+
+    return $changes;
+
+}
+
+sub update_unused {
+    my ($vmid, $conf, $volid_hash) = @_;
+
+    my $changes;
+    my $prefix = "CT $vmid:";
+
+    # Note: it is allowed to define multiple storages with same path (alias), so
+    # we need to check both 'volid' and real 'path' (two different volid can point
+    # to the same path).
+
+    # used and unused disks
+    my $refpath = {};
+    my $referenced = {};
+
+    foreach my $opt (keys %$conf) {
+	next if ($opt !~ m/^unused(\d+)$/);
+	my $vol = $volid_hash->{$conf->{$opt}};
+	$refpath->{$vol->{path}} = $vol->{volid};
+    }
+
+    foreach my $key (keys %$volid_hash) {
+	my $vol = $volid_hash->{$key};
+	my $in_use = PVE::LXC::Config->is_volume_in_use($conf, $vol->{volid});
+
+	if ($in_use) {
+	    $refpath->{$vol->{path}} = $key;
+	    delete $referenced->{$vol->{path}} if $referenced->{$vol->{path}};
+	} else {
+	    if ((!$referenced->{$vol->{path}}) && (!$refpath->{$vol->{path}})) {
+	        $referenced->{$vol->{path}} = $key;
+	    }
+	}
+
+    }
+
+    for my $key (keys %$referenced) {
+	my $disk = $referenced->{$key};
+	my $unused = PVE::LXC::Config->add_unused_volume($conf, $disk);
+
+	if ($unused) {
+	    $changes = 1;
+	    print "$prefix add unreferenced volume '$disk' as '$unused' to config.\n";
+	}
+    }
+
+    return $changes;
+
+}
+
+sub scan_volids {
+    my ($cfg, $vmid) = @_;
+
+    my $info = PVE::Storage::vdisk_list($cfg, undef, $vmid);
+
+    my $volid_hash = {};
+    foreach my $storeid (keys %$info) {
+	foreach my $item (@{$info->{$storeid}}) {
+	    next if !($item->{volid} && $item->{size});
+	    $item->{path} = PVE::Storage::path($cfg, $item->{volid});
+	    $volid_hash->{$item->{volid}} = $item;
+	}
+    }
+
+    return $volid_hash;
+}
+
+sub rescan {
+    my ($vmid, $nolock, $param) = @_;
+
+    my $cfg = PVE::Storage::config();
+
+    # FIXME: Remove once our RBD plugin can handle CT and VM on a single storage
+    # see: https://pve.proxmox.com/pipermail/pve-devel/2018-July/032900.html
+    foreach my $stor (keys %{$cfg->{ids}}) {
+	delete($cfg->{ids}->{$stor}) if !$cfg->{ids}->{$stor}->{content}->{rootdir};
+    }
+
+    print "rescan volumes...\n";
+    my $volid_hash = scan_volids($cfg, $vmid);
+
+    my $updatefn =  sub {
+	my ($vmid) = @_;
+
+	my $changes;
+	my $unused = $param->{unusedOnly};
+	my $disksize = $param->{disksizeOnly};
+
+	$unused = $disksize = 1 if ((!$unused) && (!$disksize));
+
+	my $conf = PVE::LXC::Config->load_config($vmid);
+
+	PVE::LXC::Config->check_lock($conf);
+
+	my $vm_volids = {};
+	foreach my $volid (keys %$volid_hash) {
+	    my $info = $volid_hash->{$volid};
+	    $vm_volids->{$volid} = $info if $info->{vmid} && $info->{vmid} == $vmid;
+	}
+
+	my $upu = update_unused($vmid, $conf, $vm_volids) if $unused;
+	my $upd = update_disksize($vmid, $conf, $vm_volids) if $disksize;
+	$changes = $upu // $upd;
+
+	PVE::LXC::Config->write_config($vmid, $conf) if $changes && !$param->{dryrun};
+    };
+
+    if (defined($vmid)) {
+	if ($nolock) {
+	    &$updatefn($vmid);
+	} else {
+	    PVE::LXC::Config->lock_config($vmid, $updatefn, $vmid);
+	}
+    } else {
+	my $vmlist = config_list();
+	foreach my $vmid (keys %$vmlist) {
+	    if ($nolock) {
+		&$updatefn($vmid);
+	    } else {
+		PVE::LXC::Config->lock_config($vmid, $updatefn, $vmid);
+	    }
+	}
+    }
+}
+
+
 # bash completion helper
 
 sub complete_os_templates {
-- 
2.11.0