update_vm_async: new asynchronous API

PVE/API2/Qemu.pm

@@ -839,55 +839,20 @@ my $vmconfig_update_net = sub {
     die "error hotplug $opt" if !PVE::QemuServer::vm_deviceplug($storecfg, $conf, $vmid, $opt, $net);
 };
 
-my $vm_config_perm_list = [
+# POST/PUT {vmid}/config implementation
-	    'VM.Config.Disk',
+#
-	    'VM.Config.CDROM',
+# The original API used PUT (idempotent) an we assumed that all operations
-	    'VM.Config.CPU',
+# are fast. But it turned out that almost any configuration change can
-	    'VM.Config.Memory',
+# involve hot-plug actions, or disk alloc/free. Such actions can take long
-	    'VM.Config.Network',
+# time to complete and have side effects (not idempotent).
-	    'VM.Config.HWType',
+#
-	    'VM.Config.Options',
+# The new implementation uses POST and forks a worker process. We added 
-    ];
+# a new option 'background_delay'. If specified we wait up to
+# 'background_delay' second for the worker task to complete. It returns null 
+# if the task is finished within that time, else we return the UPID.
  
-__PACKAGE__->register_method({
+my $update_vm_api  = sub {
-    name => 'update_vm',
+    my ($param, $sync) = @_;
-    path => '{vmid}/config',
-    method => 'PUT',
-    protected => 1,
-    proxyto => 'node',
-    description => "Set virtual machine options.",
-    permissions => {
-	check => ['perm', '/vms/{vmid}', $vm_config_perm_list, any => 1],
-    },
-    parameters => {
-    	additionalProperties => 0,
-	properties => PVE::QemuServer::json_config_properties(
-	    {
-		node => get_standard_option('pve-node'),
-		vmid => get_standard_option('pve-vmid'),
-		skiplock => get_standard_option('skiplock'),
-		delete => {
-		    type => 'string', format => 'pve-configid-list',
-		    description => "A list of settings you want to delete.",
-		    optional => 1,
-		},
-		force => {
-		    type => 'boolean',
-		    description => $opt_force_description,
-		    optional => 1,
-		    requires => 'delete',
-		},
-		digest => {
-		    type => 'string',
-		    description => 'Prevent changes if current configuration file has different SHA1 digest. This can be used to prevent concurrent modifications.',
-		    maxLength => 40,
-		    optional => 1,
-		}
-	    }),
-    },
-    returns => { type => 'null'},
-    code => sub {
-	my ($param) = @_;
 
     my $rpcenv = PVE::RPCEnvironment::get();
 
@@ -899,6 +864,8 @@ __PACKAGE__->register_method({
 
     my $digest = extract_param($param, 'digest');
 
+    my $background_delay = extract_param($param, 'background_delay');
+
     my @paramarr = (); # used for log message
     foreach my $key (keys %$param) {
 	push @paramarr, "-$key", $param->{$key};
@@ -974,6 +941,10 @@ __PACKAGE__->register_method({
 
 	PVE::Cluster::log_msg('info', $authuser, "update VM $vmid: " . join (' ', @paramarr));
 
+	my $worker = sub {
+
+	    print "update VM $vmid: " . join (' ', @paramarr) . "\n";
+
 	    foreach my $opt (@delete) { # delete
 		$conf = PVE::QemuServer::load_config($vmid); # update/reload
 		&$vmconfig_delete_option($rpcenv, $authuser, $conf, $storecfg, $vmid, $opt, $force);
@@ -1001,7 +972,7 @@ __PACKAGE__->register_method({
 
 		    if($opt eq 'tablet' && $param->{$opt} == 1){
 			PVE::QemuServer::vm_deviceplug(undef, $conf, $vmid, $opt);
-		    }elsif($opt eq 'tablet' && $param->{$opt} == 0){
+		    } elsif($opt eq 'tablet' && $param->{$opt} == 0){
 			PVE::QemuServer::vm_deviceunplug($vmid, $conf, $opt);
 		    }
 
@@ -1016,13 +987,147 @@ __PACKAGE__->register_method({
 		my $balloon = $param->{'balloon'} || $conf->{memory} || $defaults->{memory};
 		PVE::QemuServer::vm_mon_cmd($vmid, "balloon", value => $balloon*1024*1024);
 	    }
-
 	};
 
-	PVE::QemuServer::lock_config($vmid, $updatefn);
+	if ($sync) {
-
+	    &$worker();
 	    return undef;
-    }});
+	} else {
+	    my $upid = $rpcenv->fork_worker('qmconfig', $vmid, $authuser, $worker);
+
+	    if ($background_delay) {
+
+		# Note: It would be better to do that in the Event based HTTPServer
+		# to avoid blocking call to sleep. 
+
+		my $end_time = time() + $background_delay;
+
+		my $task = PVE::Tools::upid_decode($upid);
+
+		my $running = 1;
+		while (time() < $end_time) {
+		    $running = PVE::ProcFSTools::check_process_running($task->{pid}, $task->{pstart});
+		    last if !$running;
+		    sleep(1); # this gets interrupted when child process ends
+		}
+
+		if (!$running) {
+		    my $status = PVE::Tools::upid_read_status($upid);
+		    return undef if $status eq 'OK';
+		    die $status;
+		}
+	    } 
+
+	    return $upid;
+	}
+    };
+
+    return PVE::QemuServer::lock_config($vmid, $updatefn);
+};
+
+my $vm_config_perm_list = [
+	    'VM.Config.Disk',
+	    'VM.Config.CDROM',
+	    'VM.Config.CPU',
+	    'VM.Config.Memory',
+	    'VM.Config.Network',
+	    'VM.Config.HWType',
+	    'VM.Config.Options',
+    ];
+
+__PACKAGE__->register_method({
+    name => 'update_vm_async',
+    path => '{vmid}/config',
+    method => 'POST',
+    protected => 1,
+    proxyto => 'node',
+    description => "Set virtual machine options (asynchrounous API).",
+    permissions => {
+	check => ['perm', '/vms/{vmid}', $vm_config_perm_list, any => 1],
+    },
+    parameters => {
+    	additionalProperties => 0,
+	properties => PVE::QemuServer::json_config_properties(
+	    {
+		node => get_standard_option('pve-node'),
+		vmid => get_standard_option('pve-vmid'),
+		skiplock => get_standard_option('skiplock'),
+		delete => {
+		    type => 'string', format => 'pve-configid-list',
+		    description => "A list of settings you want to delete.",
+		    optional => 1,
+		},
+		force => {
+		    type => 'boolean',
+		    description => $opt_force_description,
+		    optional => 1,
+		    requires => 'delete',
+		},
+		digest => {
+		    type => 'string',
+		    description => 'Prevent changes if current configuration file has different SHA1 digest. This can be used to prevent concurrent modifications.',
+		    maxLength => 40,
+		    optional => 1,
+		},
+		background_delay => {
+		    type => 'integer',
+		    description => "Time to wait for the task to finish. We return 'null' if the task finish within that time.",
+		    minimum => 1,
+		    maximum => 30,
+		    optional => 1,
+		},
+	    }),
+    },
+    returns => {
+	type => 'string',
+	optional => 1,
+    },
+    code => $update_vm_api,
+});
+
+__PACKAGE__->register_method({
+    name => 'update_vm',
+    path => '{vmid}/config',
+    method => 'PUT',
+    protected => 1,
+    proxyto => 'node',
+    description => "Set virtual machine options (synchrounous API) - You should consider using the POST method instead for any actions involving hotplug or storage allocation.",
+    permissions => {
+	check => ['perm', '/vms/{vmid}', $vm_config_perm_list, any => 1],
+    },
+    parameters => {
+    	additionalProperties => 0,
+	properties => PVE::QemuServer::json_config_properties(
+	    {
+		node => get_standard_option('pve-node'),
+		vmid => get_standard_option('pve-vmid'),
+		skiplock => get_standard_option('skiplock'),
+		delete => {
+		    type => 'string', format => 'pve-configid-list',
+		    description => "A list of settings you want to delete.",
+		    optional => 1,
+		},
+		force => {
+		    type => 'boolean',
+		    description => $opt_force_description,
+		    optional => 1,
+		    requires => 'delete',
+		},
+		digest => {
+		    type => 'string',
+		    description => 'Prevent changes if current configuration file has different SHA1 digest. This can be used to prevent concurrent modifications.',
+		    maxLength => 40,
+		    optional => 1,
+		},
+	    }),
+    },
+    returns => { type => 'null' },
+    code => sub {
+	my ($param) = @_;
+	&$update_vm_api($param, 1);
+	return undef;
+    }
+});
 
 
 __PACKAGE__->register_method({