[PATCH qemu-server v6 10/18] api: record VM ID as used on destruction and remote migration

["Michael Köppl" <m.koeppl@proxmox.com>]

Record the ID of a VM as used when it is destroyed, cloned or removed
after a remote migration with --delete, so that the `/cluster/nextid`
endpoint can later optionally avoid suggesting previously used IDs.

For creation, restore and incoming remote migrations the ID is
recorded by create_and_lock_config(). VM clones write the new config
directly instead, so they record it explicitly. Recording on
destruction as well covers guests that were created before IDs were
tracked. The same holds for a remote migration with --delete, which
removes the source guest without going through the destroy API. This
call explicitly only warns on failure, since the guest has already
moved.

With 'unique' set in the next-id datacenter option, a failure to
record aborts create, clone and destroy before anything is changed.
Otherwise it only warns.

Originally-by: Daniel Krambrock <krambrock@hrz.uni-marburg.de>
Originally-by: Severen Redwood <severen.redwood@sitehost.co.nz>
Signed-off-by: Michael Köppl <m.koeppl@proxmox.com>
---
 src/PVE/API2/Qemu.pm   | 9 +++++++++
 src/PVE/QemuMigrate.pm | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
index 922c6599..9cb36e2b 100644
--- a/src/PVE/API2/Qemu.pm
+++ b/src/PVE/API2/Qemu.pm
@@ -25,6 +25,7 @@ use PVE::JSONSchema qw(get_standard_option);
 use PVE::RESTHandler;
 use PVE::ReplicationConfig;
 use PVE::GuestHelpers qw(assert_tag_permissions);
+use PVE::GuestID;
 use PVE::GuestImport;
 use PVE::QemuConfig;
 use PVE::QemuServer;
@@ -2858,6 +2859,10 @@ __PACKAGE__->register_method({
 
         $early_checks->();
 
+        # record before destroying anything, so a failure here leaves the VM intact
+        eval { PVE::GuestID::register_used_id($vmid) };
+        die "unable to destroy VM $vmid - $@" if $@;
+
         my $realcmd = sub {
             my $upid = shift;
 
@@ -4621,6 +4626,10 @@ __PACKAGE__->register_method({
                 $newconf->{description} = $param->{description};
             }
 
+            # record before the config exists, so a failure here leaves nothing behind
+            eval { PVE::GuestID::register_used_id($newid) };
+            die "unable to clone VM $vmid - $@" if $@;
+
             # create empty/temp config - this fails if VM already exists on other node
             # FIXME use PVE::QemuConfig->create_and_lock_config and adapt code
             PVE::Tools::file_set_contents($conffile, "# qmclone temporary file\nlock: clone\n");
diff --git a/src/PVE/QemuMigrate.pm b/src/PVE/QemuMigrate.pm
index 8da6f15d..3f2d9b91 100644
--- a/src/PVE/QemuMigrate.pm
+++ b/src/PVE/QemuMigrate.pm
@@ -13,6 +13,7 @@ use PVE::Cluster;
 use PVE::Format qw(render_bytes);
 use PVE::Firewall::Helpers;
 use PVE::GuestHelpers qw(safe_boolean_ne safe_string_ne);
+use PVE::GuestID;
 use PVE::INotify;
 use PVE::JSONSchema;
 use PVE::RPCEnvironment;
@@ -1904,6 +1905,9 @@ sub phase3_cleanup {
     }
 
     if ($self->{opts}->{remote} && $self->{opts}->{delete}) {
+        eval { PVE::GuestID::register_used_id($vmid) };
+        warn $@ if $@;
+
         eval { PVE::QemuServer::destroy_vm($self->{storecfg}, $vmid, 1, undef, 0) };
         warn "Failed to remove source VM - $@\n" if $@;
     }
-- 
2.47.3