Re: [pve-devel] [PATCH qemu-server 1/1] api: migration preconditions: add node affinity as blocking cause

["Daniel Kral" <d.kral@proxmox.com>]

On Mon Jan 19, 2026 at 4:00 PM CET, Fiona Ebner wrote:
> Am 15.12.25 um 4:54 PM schrieb Daniel Kral:
>> Signed-off-by: Daniel Kral <d.kral@proxmox.com>
>> ---
>> Needs a version bump for pve-ha-manager.
>> 
>
> Such a bump is only required in the sense that the enum variant cannot
> actually happen before new ha-manager is installed. The patch here could
> be applied without such a bump, upgraded and nothing would break.
>
> But technically, it's a breaking change in the other direction. New HA
> manager might cause old qemu-server to return something that was not
> declared in the return schema. I guess it won't be a huge issue in
> practice though. API clients already need to be prepared for new
> variants being returned and the issue would only manifest if the API
> client checks the correctness of the result against the installed, old
> qemu-server API schema.

Well this threw me in an unexpected rabbit hole ;)

I only added the bump here because I noticed that we do check the
correctness of the return value of the API handler at the CLI (e.g. if
`ha-manager migrate vm:100 node1` returns 'node-affinity' as a blocking
cause), then it will fail

```
# ha-manager migrate vm:100 node1
400 Result verification failed
blocking-resources[0].cause: value 'node-affinity' does not have a value in the enumeration 'resource-affinity'
ha-manager crm-command migrate <sid> <node>
```

and indeed we verify the result at every CLI invocation [0] (the third
parameter toggles result verification in [1]).

One could enable result verification on a case-by-case basis when
calling the API method directly via the package (e.g.
PVE::API2::Example->method({ param: "something"}, 1)) [2], but otherwise
we do not validate the response with pvesh nor the HTTP server [3] [4]
[5], so this is indeed fine without as bump!

Sorry for going off on a tangent here, I was curious where that
happened.

[0] https://git.proxmox.com/?p=pve-common.git;a=blob;f=src/PVE/RESTHandler.pm;h=cc82fe8df56a429d64094209d264621de3d4e89e;hb=refs/heads/master#l1019
[1] https://git.proxmox.com/?p=pve-common.git;a=blob;f=src/PVE/RESTHandler.pm;h=cc82fe8df56a429d64094209d264621de3d4e89e;hb=refs/heads/master#l486
[2] https://git.proxmox.com/?p=pve-common.git;a=blob;f=src/PVE/RESTHandler.pm;h=cc82fe8df56a429d64094209d264621de3d4e89e;hb=refs/heads/master#l340
[3] https://git.proxmox.com/?p=pve-common.git;a=blob;f=src/PVE/RESTHandler.pm;h=cc82fe8df56a429d64094209d264621de3d4e89e;hb=refs/heads/master#l232
[4] https://git.proxmox.com/?p=pve-common.git;a=blob;f=src/PVE/RESTHandler.pm;h=cc82fe8df56a429d64094209d264621de3d4e89e;hb=refs/heads/master#l413
[5] https://git.proxmox.com/?p=pve-manager.git;a=blob;f=PVE/HTTPServer.pm;h=bb8052e3b428f9b8d11d63f7c7e9d45f40344dca;hb=HEAD#l192

>
>>  src/PVE/API2/Qemu.pm | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
>> index 190878de..5c4f6eb3 100644
>> --- a/src/PVE/API2/Qemu.pm
>> +++ b/src/PVE/API2/Qemu.pm
>> @@ -5196,7 +5196,7 @@ __PACKAGE__->register_method({
>>                                      type => 'string',
>>                                      description => "The reason why the HA"
>>                                          . " resource is blocking the migration.",
>> -                                    enum => ['resource-affinity'],
>> +                                    enum => ['node-affinity', 'resource-affinity'],
>>                                  },
>>                              },
>>                          },



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