Don't use systemd socket activation becuase startup ordering is weird.

[geofft]

Fixes #9.

Co-authored-by: Geoffrey Thomas geofft@twosigma.com

[flokli]

This might have gotten fixed upstream in systemd/systemd-stable@5da595d btw

[pkern]

I wonder if we could undo this eventually (I don't have real world data to back this though), because without socket activation binaries that require nsncd need to take an explicit systemd service dependency on it (well, a Wants=). Which I guess is kinda fine except that it does not provide the transparent system support for them anymore.

[leifwalsh]

@pkern if I still understand #9 correctly, such a system would deadlock if they do a lookup during their activation. If you're able to test it and show that it doesn't, that would be pretty exciting.

Can I leave you to that and to let us know if you have trouble setting up a test?

[flokli]

I'd be up to giving this another go - it might get rid of some spurious user lookup failures we have during NixOS system activations if both nsncd and a service referring to a dynamic user (provided by nss-systemd) are restarted.