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What happens if 'sudoers: sss' is in nsswitch.conf, but sssd isn't configured for it or there is no LDAP? Does it properly fall back to the file? -- notting
I haven't tested this but the proper configuration would be "sudoers: sss files" or "sudoers: files sss" depending on the order you want. We definitely need to support ordering of databases. --jhrozek