debugging

Canonical’s Multipass is a wonderful tool for bootstrapping Ubuntu VMs on any platform, including macOS on Apple Silicon (M1/arm64). It works well, as everything, until networking breaks. The issue, debugging, and resolution story from this long afternoon reveals few tricks about both Multipass and Application Firewall on macOS, so I’ll describe it in detail.

This tale is yet another confirmation of the fact that majority of macOS problems are coming from corporate security tools - I didn’t have such issues even at Hackintosh era. It all started on a corporate MacBook when I had the bunch of Multipass-created VMs that suddenly stopped working - they were starting up, QEMU process was running, but Multipass couldn’t check their status (it uses SSH for that). Moreover, creation of new ones was also breaking in the worst moment - QEMU process started and Multipass waited for cloud-init loaded from virtual CD-ROM to get networking and SSH. And then it just timed out.

Time for a short tale about an interesting debugging challenge I had recently. Programming issue itself was not the hardest or most involving of all time, probably not even of this year for me, but the mixture of circumstances and debugging techniques used makes it worth telling.

Obviously, many details will be skipped, but I can mention some common components used. But keep in mind that’s a real-world scenario, so the initial environment could definitely be better.