The `update-machine-ids.sh` shell script helps update the `sshca-data`
SealedSecret with the current contents of the `machine-ids.json` file
(stored locally, not tracked in Git).
[sshca] is a simple web service I wrote to automatically create signed
SSH certificates for hosts' public keys. It authenticates hosts by
their machine UUID, which it can find using the libvirt API.
[sshca]: https://git.pyrocufflink.net/dustin/sshca
Dustin