Re: [pve-devel] [PATCH qemu-server 1/1] Add VM hooks for pre/post-migrate on target/source

[Stefan Hanreich <s.hanreich@proxmox.com>]

On 9/26/22 17:38, Thomas Lamprecht wrote:
> I don't like that there's no commit message (the cover letter is more for general/meta
> info, it doesn't gets into git after all, would require doing pull requests which we
> (currently) don't do in most cases).
> 
> Besides that I'd rather avoid extending SSH usage further, a long term goal is to
> allow user running PVE clusters with all its features without any SSH connection
> required. For VM migration we already got the mtunnel which can be used for such
> control stuff; otherwise one can get an API client instead, but there we'd need to
> make some sort of execution path part of the public API, can be fine; as the CLI
> really isn't /that/ different from the API in publicity/stableness regard (if its
> there it will be used, a description comment is a very weak gate), so I'd find a
> fully internal handling (i.e., neither CLI nor API exposure) nicer, mtunnel should
> make that relatively simple, for CTs one may need to add a similar mechanism.
> 
> Also, this requires the script to be available on all notes, the docs should reflect
> that.

Makes sense, I will look into using mtunnel for this! Will also add a 
short note to the documentation.

> Am 22/09/2022 um 16:13 schrieb Stefan Hanreich:
>> Signed-off-by: Stefan Hanreich <s.hanreich@proxmox.com>
>> ---
>>   PVE/CLI/qm.pm                         | 50 +++++++++++++++++++++++++++
>>   PVE/QemuMigrate.pm                    | 23 ++++++++++++
>>   test/MigrationTest/QemuMigrateMock.pm |  4 +++
>>   3 files changed, 77 insertions(+)
>>
>> diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
>> index 6a2e161..4161e6e 100755
>> --- a/PVE/CLI/qm.pm
>> +++ b/PVE/CLI/qm.pm
>> @@ -838,6 +838,54 @@ __PACKAGE__->register_method({
>>   	return;
>>       }});
>>   
>> +__PACKAGE__->register_method ({
>> +    name => 'pre_migrate',
>> +    path => 'pre_migrate',
>> +    method => 'POST',
>> +    description => "Run pre-migrate hook for VM <vmid> - do not use manually.",
>> +    parameters => {
>> +	additionalProperties => 0,
>> +	properties => {
>> +	    vmid => get_standard_option('pve-vmid', { completion => \&PVE::QemuServer::complete_vmid }),
>> +	    'source-node' => get_standard_option('pve-node'),
>> +	},
>> +    },
>> +    returns => { type => 'null'},
>> +    code => sub {
>> +	my ($param) = @_;
>> +
>> +	my $vmid = $param->{vmid};
>> +	my $source_node = $param->{'source-node'};
>> +	my $conf = PVE::QemuConfig->load_config($vmid, $source_node);
>> +
>> +	PVE::GuestHelpers::exec_hookscript($conf, $vmid, "pre-migrate-target", 1);
>> +
>> +	return;
>> +    }});
>> +
>> +__PACKAGE__->register_method ({
>> +    name => 'post_migrate',
>> +    path => 'post_migrate',
>> +    method => 'POST',
>> +    description => "Run post-migrate hook for VM <vmid> - do not use manually.",
>> +    parameters => {
>> +	additionalProperties => 0,
>> +	properties => {
>> +	    vmid => get_standard_option('pve-vmid', { completion => \&PVE::QemuServer::complete_vmid }),
>> +	},
>> +    },
>> +    returns => { type => 'null'},
>> +    code => sub {
>> +	my ($param) = @_;
>> +
>> +	my $vmid = $param->{vmid};
>> +	my $conf = PVE::QemuConfig->load_config($vmid);
>> +
>> +	PVE::GuestHelpers::exec_hookscript($conf, $vmid, "post-migrate-target");
>> +
>> +	return;
>> +    }});
>> +
>>   my $print_agent_result = sub {
>>       my ($data) = @_;
>>   
>> @@ -988,6 +1036,8 @@ our $cmddef = {
>>   	    }],
>>       },
>>   
>> +    'pre-migrate' => [ __PACKAGE__, 'pre_migrate', ['vmid', 'source-node']],
>> +    'post-migrate' => [ __PACKAGE__, 'post_migrate', ['vmid']],
>>   };
>>   
>>   1;
>> diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
>> index d52dc8d..b113dec 100644
>> --- a/PVE/QemuMigrate.pm
>> +++ b/PVE/QemuMigrate.pm
>> @@ -1284,4 +1284,27 @@ sub round_powerof2 {
>>       return 2 << int(log($_[0]-1)/log(2));
>>   }
>>   
>> +sub pre_migration_hooks {
>> +    my ($self, $vmid) = @_;
>> +
>> +    PVE::GuestHelpers::exec_hookscript($self->{vmconf}, $vmid, 'pre-migrate-source', 1);
>> +
>> +    my $node = PVE::INotify::nodename();
>> +    my $cmd = [ @{$self->{rem_ssh}}, "qm", "pre-migrate", $vmid, $node ];
>> +
>> +    eval { $self->cmd($cmd); };
>> +    die "$@\n" if $@;
>> +}
>> +
>> +sub post_migration_hooks {
>> +    my ($self, $vmid) = @_;
>> +
>> +    PVE::GuestHelpers::exec_hookscript($self->{vmconf}, $vmid, 'post-migrate-source');
>> +
>> +    my $cmd = [ @{$self->{rem_ssh}}, "qm", "post-migrate", $vmid ];
>> +
>> +    eval { $self->cmd($cmd); };
>> +    die "$@\n" if $@;
>> +}
>> +
>>   1;
>> diff --git a/test/MigrationTest/QemuMigrateMock.pm b/test/MigrationTest/QemuMigrateMock.pm
>> index f2c0281..461b390 100644
>> --- a/test/MigrationTest/QemuMigrateMock.pm
>> +++ b/test/MigrationTest/QemuMigrateMock.pm
>> @@ -298,6 +298,10 @@ $MigrationTest::Shared::tools_module->mock(
>>   			return 0;
>>   		    } elsif ($cmd eq 'stop') {
>>   			return 0;
>> +		    } elsif ($cmd eq 'pre-migrate') {
>> +			return 0;
>> +		    } elsif ($cmd eq 'post-migrate') {
>> +			return 0;
>>   		    }
>>   		    die "run_command (mocked) ssh qm command - implement me: ${cmd_msg}";
>>   		} elsif ($cmd eq 'pvesm') {
>