No SSSD support in snaps (nsswitch.conf)

[chipaca]

have you looked at

Accessing unix users and groups from a strict snap

Probably the only way you’re going to reliably access exotic user/group tables in confinement would be via a proxy like nscd (or an equivalent like unscd). It looks like any of the interfaces that end up doing #include <abstractions/nameservice> should grant access to its socket. One such interface is network, which you might already be plugging. I realise that using nscd can have some drawbacks, but it might be the best option here.

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