Solving an issue with VirtualBMC running in macOS

macos-vbmc.md

How to fix VirtualBMC in macOS

After installing VirtualBMC in macOS, starting the server and adding a BMC for at least one VM, and then trying to start that BMC, you get the following error:

INFO VirtualBMC [-] Started vBMC server on port 50891
ERROR VirtualBMC [-] Control server error: Can't pickle local object 'VirtualBMCManager._sync_vbmc_states..vbmc_runner'

This is because the multiprocessing module needs to specify fork as the startup method, since starting with Python 3.8 for macOS the startup method has been replaced by spawn.

Add a line to the /path/to/python/site-packages/virtualbmc/manager.py file:

                if not instance or not instance.is_alive():
                
                    multiprocessing.set_start_method('fork', force=True) <<--
                    instance = multiprocessing.Process(
                        name='vbmcd-managing-domain-%s' % domain_name,
                        target=vbmc_runner,
                        args=(bmc_config,)
                    )

Now you can start a VBMC server and add BMC to different VMs without error.

vbmc list
+--------------+---------+---------+------+
| Domain name  | Status  | Address | Port |
+--------------+---------+---------+------+
| compute-1    | running | ::      | 6241 |
| compute-2    | running | ::      | 6242 |
| controller-1 | running | ::      | 6233 |
| controller-2 | running | ::      | 6234 |
| controller-3 | running | ::      | 6235 |
+--------------+---------+---------+------+