[pve-devel] [PATCH storage 3/9] plugin: dir: handle ova files for import

Fabian Grünbichler f.gruenbichler at proxmox.com
Wed Apr 17 15:39:10 CEST 2024


On April 17, 2024 3:07 pm, Dominik Csapak wrote:
> On 4/17/24 12:52, Fiona Ebner wrote:
>> Am 16.04.24 um 15:18 schrieb Dominik Csapak:
>>> since we want to handle ova files (which are only ovf+vmdks bundled in a
>>> tar file) for import, add code that handles that.
>>>
>>> we introduce a valid volname for files contained in ovas like this:
>>>
>>>   storage:import/archive.ova/disk-1.vmdk
>>>
>>> by basically treating the last part of the path as the name for the
>>> contained disk we want.
>>>
>>> we then provide 3 functions to use for that:
>>>
>>> * copy_needs_extraction: determines from the given volid (like above) if
>>>    that needs extraction to copy it, currently only 'import' vtype +
>>>    defined format returns true here (if we have more options in the
>>>    future, we can of course easily extend that)
>>>
>>> * extract_disk_from_import_file: this actually extracts the file from
>>>    the archive. Currently only ova is supported, so the extraction with
>>>    'tar' is hardcoded, but again we can easily extend/modify that should
>>>    we need to.
>>>
>>>    we currently extract into the import storage in a directory named:
>>>    `.tmp_<pid>_<targetvmid>` which should not clash with concurrent
>>>    operations (though we do extract it multiple times then)
>>>
>> 
>> Could we do "extract upon upload", "tar upon download" instead? Sure
>> some people surely want to drop the ova manually, but we could tell them
>> they need to extract it first too. Depending on the amount of headache
>> this would save us, it might be worth it.
> 
> we could, but this opens a whole other can of worms, namely
> what to do with conflicting filenames for different ovas?
> 
> we'd then either have to magically match the paths from the ovfs
> to some subdir that don't overlap

we could just use the ova name as dir name, and never store the ova
under that name but use some tmp placeholder for that ;)

> 
> or we'd have to abort everytime we encounter identical disk names
> 
> IMHO this would be less practical than just extract on demand...
> 
>> 
>>>    alternatively we could implement either a 'tmpstorage' parameter,
>>>    or use e.g. '/var/tmp/' or similar, but re-using the current storage
>>>    seemed ok.
>>>
>>> * cleanup_extracted_image: intended to cleanup the extracted images from
>>>    above, including the surrounding temporary directory
>>>
>>> we have to modify the `parse_ovf` a bit to handle the missing disk
>>> images, and we parse the size out of the ovf part (since this is
>>> informal only, it should be no problem if we cannot parse it sometimes)
>>>
>>> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
>>> ---
>>>   src/PVE/API2/Storage/Status.pm |  1 +
>>>   src/PVE/Storage.pm             | 59 ++++++++++++++++++++++++++++++++++
>>>   src/PVE/Storage/DirPlugin.pm   | 13 +++++++-
>>>   src/PVE/Storage/OVF.pm         | 53 ++++++++++++++++++++++++++----
>>>   src/PVE/Storage/Plugin.pm      |  5 +++
>>>   5 files changed, 123 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/src/PVE/API2/Storage/Status.pm b/src/PVE/API2/Storage/Status.pm
>>> index f7e324f..77ed57c 100644
>>> --- a/src/PVE/API2/Storage/Status.pm
>>> +++ b/src/PVE/API2/Storage/Status.pm
>>> @@ -749,6 +749,7 @@ __PACKAGE__->register_method({
>>>   				'efi-state-lost',
>>>   				'guest-is-running',
>>>   				'nvme-unsupported',
>>> +				'ova-needs-extracting',
>>>   				'ovmf-with-lsi-unsupported',
>>>   				'serial-port-socket-only',
>>>   			    ],
>>> diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
>>> index f8ea93d..bc073ef 100755
>>> --- a/src/PVE/Storage.pm
>>> +++ b/src/PVE/Storage.pm
>>> @@ -2189,4 +2189,63 @@ sub get_import_metadata {
>>>       return $plugin->get_import_metadata($scfg, $volname, $storeid);
>>>   }
>>>   
>> 
>> Shouldn't the following three functions call into plugin methods
>> instead? That'd seem much more future-proof to me.
> 
> could be, i just did not want to extend the plugin api for that
> but as fabian wrote, maybe we should put them in qemu-server
> altogether for now?
> 
> (after thinking about it a bit, i'd be in favor of putting it in
> qemu-server, because mainly i don't want to add to the plugin api further)
> 
> what do you think @fiona @fabian?

another alternative would be to put them into the non-storage-plugin OVF
helper module?

>>> +sub copy_needs_extraction {
>>> +    my ($volid) = @_;
>>> +    my ($storeid, $volname) = parse_volume_id($volid);
>>> +    my $cfg = config();
>>> +    my $scfg = storage_config($cfg, $storeid);
>>> +    my $plugin = PVE::Storage::Plugin->lookup($scfg->{type});
>>> +
>>> +    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $file_format) =
>>> +	$plugin->parse_volname($volname);
>>> +
>>> +    return $vtype eq 'import' && defined($file_format);
>> 
>> E.g this seems rather hacky, and puts a weird coupling on a future
>> import plugin's parse_volname() function (presence of $file_format).
> 
> would it be better to check the volid again for '.ova/something$' ?
> or do you have a better idea?
> (especially if we want to have this maybe in qemu-server)

hmm, could parse_volname return 'ova' as format? or 'ova+vmdk'? we don't
actually need the format for extracting, and afterwards we get it from
the extract file name anyway?

>>> +}
>>> +
>>> +sub extract_disk_from_import_file {
>>> +    my ($volid, $vmid) = @_;
>>> +
>>> +    my ($storeid, $volname) = parse_volume_id($volid);
>>> +    my $cfg = config();
>>> +    my $scfg = storage_config($cfg, $storeid);
>>> +    my $plugin = PVE::Storage::Plugin->lookup($scfg->{type});
>>> +
>>> +    my ($vtype, $name, undef, undef, undef, undef, $file_format) =
>>> +	$plugin->parse_volname($volname);
>>> +
>>> +    die "only files with content type 'import' can be extracted\n"
>>> +	if $vtype ne 'import' || !defined($file_format);
>>> +
>>> +    # extract the inner file from the name
>>> +    if ($volid =~ m!${name}/([^/]+)$!) {
>>> +	$name = $1;
>>> +    }
>>> +
>>> +    my ($source_file) = $plugin->path($scfg, $volname, $storeid);
>>> +
>>> +    my $destdir = $plugin->get_subdir($scfg, 'import');
>>> +    my $pid = $$;
>>> +    $destdir .= "/.tmp_${pid}_${vmid}";
>>> +    mkdir $destdir;
>>> +
>>> +    ($source_file) = $source_file =~ m|^(/.*)|; # untaint
>>> +
>>> +    run_command(['tar', '-x', '-C', $destdir, '-f', $source_file, $name]);
>>> +
>>> +    return "$destdir/$name";
>>> +}
>>> +
>>> +sub cleanup_extracted_image {
>>> +    my ($source) = @_;
>>> +
>>> +    if ($source =~ m|^(/.+/\.tmp_[0-9]+_[0-9]+)/[^/]+$|) {
>>> +	my $tmpdir = $1;
>>> +
>>> +	unlink $source or $! == ENOENT or die "removing image $source failed: $!\n";
>>> +	rmdir $tmpdir or $! == ENOENT or die "removing tmpdir $tmpdir failed: $!\n";
>>> +    } else {
>>> +	die "invalid extraced image path '$source'\n";
>>> +    }
>>> +}
>>> +
>>>   1;
>>> diff --git a/src/PVE/Storage/DirPlugin.pm b/src/PVE/Storage/DirPlugin.pm
>>> index 4dc7708..50ceab7 100644
>>> --- a/src/PVE/Storage/DirPlugin.pm
>>> +++ b/src/PVE/Storage/DirPlugin.pm
>>> @@ -260,14 +260,25 @@ sub get_import_metadata {
>>>       # NOTE: all types must be added to the return schema of the import-metadata API endpoint
>>>       my $warnings = [];
>>>   
>>> +    my $isOva = 0;
>>> +    if ($path =~ m!\.ova!) {
>> 
>> Would be nicer if parse_volname() would return the $file_format and we
>> chould check for that. Also missing the $ in the regex, so you'd
>> mismatch a weird filename like ABC.ovaXYZ.ovf or?
> 
> yeah the $ is missing, and yes, we could return ova/ovf as format there
> as we want to change the 'needs extracting' check anyway
> 
> 
>> 
>>> +	$isOva = 1;
>>> +	push @$warnings, { type => 'ova-needs-extracting' };
>>> +    }
>>>       my $res = PVE::Storage::OVF::parse_ovf($path, $isOva);
>>>       my $disks = {};
>>>       for my $disk ($res->{disks}->@*) {
>>>   	my $id = $disk->{disk_address};
>>>   	my $size = $disk->{virtual_size};
>>>   	my $path = $disk->{relative_path};
>>> +	my $volid;
>>> +	if ($isOva) {
>>> +	    $volid = "$storeid:$volname/$path";
>>> +	} else {
>>> +	    $volid = "$storeid:import/$path",
>>> +	}
>>>   	$disks->{$id} = {
>>> -	    volid => "$storeid:import/$path",
>>> +	    volid => $volid,
>>>   	    defined($size) ? (size => $size) : (),
>>>   	};
>>>       }
>>> diff --git a/src/PVE/Storage/OVF.pm b/src/PVE/Storage/OVF.pm
>>> index 4a322b9..fb850a8 100644
>>> --- a/src/PVE/Storage/OVF.pm
>>> +++ b/src/PVE/Storage/OVF.pm
>>> @@ -85,11 +85,37 @@ sub id_to_pve {
>>>       }
>>>   }
>>>   
>>> +# technically defined in DSP0004 (https://www.dmtf.org/dsp/DSP0004) as an ABNF
>>> +# but realistically this always takes the form of 'bytes * base^exponent'
>> 
>> The comment wrongly says 'bytes' instead of 'byte' (your test examples
>> confirm this).
>> 
>>> +sub try_parse_capacity_unit {
>>> +    my ($unit_text) = @_;
>>> +
>>> +    if ($unit_text =~ m/^\s*byte\s*\*\s*([0-9]+)\s*\^\s*([0-9]+)\s*$/) {
>> 
>> Fun regex :P
>> 
>>> +	my $base = $1;
>>> +	my $exp = $2;
>>> +	return $base ** $exp;
>>> +    }
>>> +
>>> +    return undef;
>>> +}
>>> +
>> 
>> (...)
>> 
>>> diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
>>> index deaf8b2..ea069ab 100644
>>> --- a/src/PVE/Storage/Plugin.pm
>>> +++ b/src/PVE/Storage/Plugin.pm
>>> @@ -654,6 +654,11 @@ sub parse_volname {
>>>   	return ('backup', $fn);
>>>       } elsif ($volname =~ m!^snippets/([^/]+)$!) {
>>>   	return ('snippets', $1);
>>> +    } elsif ($volname =~ m!^import/([^/]+\.ova)\/([^/]+)$!) {
>>> +	my $archive = $1;
>>> +	my $file = $2;
>>> +	my (undef, $format, undef) = parse_name_dir($file);
>>> +	return ('import', $archive, 0, undef, undef, undef, $format);
>> 
>> So we return the same $name for different things here? Not super happy
>> with that either. If we were to get creative we could say the archive is
>> the "base" of the image, but surely also comes with caveats.
> 
> i'll change this in a v2 should not be necessary
> 
>> 
>>>       } elsif ($volname =~ m!^import/([^/]+$PVE::Storage::IMPORT_EXT_RE_1)$!) {
>>>   	return ('import', $1);
>>>       } elsif ($volname =~ m!^import/([^/]+\.(raw|vmdk|qcow2))$!) {
> 
> 
> 
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