From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id D6CB66098A for ; Thu, 3 Sep 2020 09:46:46 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id CC43D1616E for ; Thu, 3 Sep 2020 09:46:46 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 82DDA16161 for ; Thu, 3 Sep 2020 09:46:44 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 4B886449F6 for ; Thu, 3 Sep 2020 09:46:44 +0200 (CEST) Date: Thu, 03 Sep 2020 09:46:35 +0200 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= To: Proxmox VE development discussion References: <20200901124421.25901-1-a.lauterer@proxmox.com> <20200901124421.25901-2-a.lauterer@proxmox.com> In-Reply-To: <20200901124421.25901-2-a.lauterer@proxmox.com> MIME-Version: 1.0 User-Agent: astroid/0.15.0 (https://github.com/astroidmail/astroid) Message-Id: <1599118042.6ymt99i7i5.astroid@nora.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-SPAM-LEVEL: Spam detection results: 0 AWL 0.031 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [proxmox.com, qemu.pm, drive.pm] Subject: Re: [pve-devel] [PATCH v2 qemu-server 1/5] disk reassign: add API endpoint X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Sep 2020 07:46:46 -0000 On September 1, 2020 2:44 pm, Aaron Lauterer wrote: > The goal of this new API endpoint is to provide an easy way to move a > disk between VMs as this was only possible with manual intervention > until now. Either by renaming the VM disk or by manually adding the > disks volid to the config of the other VM. >=20 > The latter can easily cause unexpected behavior such as disks attached > to VM B would be deleted if it used to be a disk of VM A. This happens > because PVE assumes that the VMID in the volname always matches the VM > the disk is attached to and thus, would remove any disk with VMID A > when VM A was deleted. >=20 > The term `reassign` was chosen as it is not yet used > for disk VMs. >=20 > Signed-off-by: Aaron Lauterer > --- > v1 -> v2: print config key and volid info at the end of the job so it > shows up on the CLI and task log >=20 > rfc -> v1: > * add support to reassign unused disks > * add support to provide a config digest for the target vm > * add additional check if disk key is present in config > * reorder checks a bit >=20 > In order to support unused disk I had to extend > PVE::QemuServer::Drive::valid_drive_names for the API parameter > validation. >=20 > Checks are ordered so that cheap tests are run at the first chance to > fail early. >=20 > The check if both VMs are present on the node is a bit redundant because > locking the config files will fail if the VM is not present. But with > the additional check we can provide a useful error message to the user > instead of a "Configuration file xyz does not exist" error. >=20 > Feedback, especially on the checks is welcome. >=20 >=20 > PVE/API2/Qemu.pm | 108 ++++++++++++++++++++++++++++++++++++++++ > PVE/QemuServer/Drive.pm | 4 ++ > 2 files changed, 112 insertions(+) >=20 > diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm > index 8da616a..45aadbf 100644 > --- a/PVE/API2/Qemu.pm > +++ b/PVE/API2/Qemu.pm > @@ -4265,4 +4265,112 @@ __PACKAGE__->register_method({ > return PVE::QemuServer::Cloudinit::dump_cloudinit_config($conf, $param-= >{vmid}, $param->{type}); > }}); > =20 > +__PACKAGE__->register_method({ > + name =3D> 'reassign_vm_disk', > + path =3D> '{vmid}/reassign_disk', > + method =3D> 'POST', > + protected =3D> 1, > + proxyto =3D> 'node', > + description =3D> "Reassign a disk to another VM", > + permissions =3D> { > + description =3D> "You need 'VM.Config.Disk' permissions on /vms/{vmid},= and 'Datastore.Allocate' permissions on the storage.", > + check =3D> [ 'and', > + ['perm', '/vms/{vmid}', [ 'VM.Config.Disk' ]], > + ['perm', '/storage/{storage}', [ 'Datastore.Allocate' ]], > + ], > + }, > + parameters =3D> { > + additionalProperties =3D> 0, > + properties =3D> { > + node =3D> get_standard_option('pve-node'), > + vmid =3D> get_standard_option('pve-vmid', { completion =3D> \&PVE::= QemuServer::complete_vmid }), > + target_vmid =3D> get_standard_option('pve-vmid', { completion =3D> = \&PVE::QemuServer::complete_vmid }), > + disk =3D> { > + type =3D> 'string', > + description =3D> "The config key of the disk to move (for example, ide= 0 or scsi1).", > + enum =3D> [PVE::QemuServer::Drive::valid_drive_names_with_unused()], > + }, > + digest =3D> { > + type =3D> 'string', > + description =3D> 'Prevent changes if current the configuration file of= the source VM has a different SHA1 digest. This can be used to prevent con= current modifications.', > + maxLength =3D> 40, > + optional =3D> 1, > + }, > + target_digest =3D> { > + type =3D> 'string', > + description =3D> 'Prevent changes if current the configuration file of= the target VM has a different SHA1 digest. This can be used to prevent con= current modifications.', > + maxLength =3D> 40, > + optional =3D> 1, > + }, > + }, > + }, > + returns =3D> { > + type =3D> 'string', > + description =3D> "the task ID.", > + }, > + code =3D> sub { > + my ($param) =3D @_; > + > + my $rpcenv =3D PVE::RPCEnvironment::get(); > + my $authuser =3D $rpcenv->get_user(); > + > + my $node =3D extract_param($param, 'node'); > + my $vmid =3D extract_param($param, 'vmid'); > + my $target_vmid =3D extract_param($param, 'target_vmid'); > + my $digest =3D extract_param($param, 'digest'); > + my $target_digest =3D extract_param($param, 'target_digest'); > + my $disk =3D extract_param($param, 'disk'); > + > + my $storecfg =3D PVE::Storage::config(); > + > + die "You cannot reassign a disk to the same VM\n" > + if $vmid eq $target_vmid; > + > + my $vmlist =3D PVE::QemuServer::vzlist(); > + die "Both VMs need to be on the same node\n" > + if !$vmlist->{$vmid}->{exists} || !$vmlist->{$target_vmid}->{exists= }; we could skip this if the target storage is shared, and let the user run=20 'rescan' afterwards? > + > + return PVE::QemuConfig->lock_config($vmid, sub { > + my $conf =3D PVE::QemuConfig->load_config($vmid); > + PVE::QemuConfig->check_lock($conf); > + > + die "Source VM config checksum missmatch (file change by other user= ?)\n" > + if $digest && $digest ne $conf->{digest}; PVE::Tools::assert_if_modified > + > + die "Disk '${disk}' does not exist\n" > + if !exists($conf->{$disk}); why not defined? > + > + my $drive =3D PVE::QemuServer::parse_drive($disk, $conf->{$disk}); > + die "disk '$disk' has no associated volume\n" if !$drive->{file}; missing check for whether it's actually volume-based, and not=20 pass-through.. what about templates/base volumes/linked=20 clones/snapshots? > + die "Cannot reassign a cdrom drive\n" if PVE::QemuServer::drive_is_= cdrom($drive, 1); "CD drive contents can't be reassigned.\n" > + > + die "Cannot reassign disk while the source VM is running\n" > + if PVE::QemuServer::check_running($vmid) && $disk !~ m/unused[0-9]/; > + > + return PVE::QemuConfig->lock_config($target_vmid, sub { > + my $target_conf =3D PVE::QemuConfig->load_config($target_vmid); > + PVE::QemuConfig->check_lock($target_conf); > + > + die "Target VM config checksum missmatch (file change by other user?)\= n" > + if $target_digest && $target_digest ne $target_conf->{digest}; same as above. > + > + PVE::Cluster::log_msg('info', $authuser, "reassign disk VM $vmid: reas= sign --disk $disk --target_vmid $target_vmid"); > + > + my $realcmd =3D sub { > + my $new_volid =3D PVE::Storage::reassign_volume($storecfg, $drive-= >{file}, $target_vmid); > + > + delete $conf->{$disk}; > + PVE::QemuConfig->write_config($vmid, $conf); > + > + my $key =3D PVE::QemuConfig->add_unused_volume($target_conf, $new_= volid); this can fail, now the volume is unreferenced altogether -> maybe wrap=20 in an eval and print a more helpful error message including the new=20 volid? > + PVE::QemuConfig->write_config($target_vmid, $target_conf); > + > + print "reassigned disk to VM ${target_vmid} as '${key}: ${new_voli= d}'\n"; or split this up, and print 'renamed volume '$old_volid' to '$new_volid'\n"; after the call to reassign_volume, and print the config changes=20 individually after the respective actions? print "remove disk '$disk' from VM '$vmid'\n"; print "added volume '$new_volid' as '$key' to VM '$target_vmid'\n"; > + }; > + > + return $rpcenv->fork_worker('qmreassign', $vmid, $authuser, $realcmd); I am not so happy about lock_config( load_config; lock_config( load_config;=20 fork_worker( cfs_lock/write_config ) ) ) as it tends to accumulate more checks and extra functionality and at=20 some point might introduce an inconsistency.. note that the current=20 version seems fine (we always lock first then load, we only look at=20 config files that belong to a specific node, ...), but maybe we could=20 switch to # check for early return/nice error (conf1, conf2) =3D load_and_check_sub(id1, id2); fork_worker( lock_config( lock_config( # recheck in locked worker context (conf1, conf2) =3D load_and_check_sub(id1, id2); ... ) ) ) to make it more fool/future-proof, especially since the checks are rather c= heap.. > + }); > + }); > + }}); > + > 1; > diff --git a/PVE/QemuServer/Drive.pm b/PVE/QemuServer/Drive.pm > index 91c33f8..d2f59cd 100644 > --- a/PVE/QemuServer/Drive.pm > +++ b/PVE/QemuServer/Drive.pm > @@ -383,6 +383,10 @@ sub valid_drive_names { > 'efidisk0'); > } > =20 > +sub valid_drive_names_with_unused { > + return (valid_drive_names(), map {"unused$_"} (0 .. ($MAX_UNUSED_DIS= KS -1))); > +} > + > sub is_valid_drivename { > my $dev =3D shift; > =20 > --=20 > 2.20.1 >=20 >=20 >=20 > _______________________________________________ > pve-devel mailing list > pve-devel@lists.proxmox.com > https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel >=20 >=20 >=20 =