systemd moans about krb5.keytab at boot time

```
# systemctl --failed
   UNIT                LOAD   ACTIVE SUB    DESCRIPTION
* rpc-svcgssd.service loaded failed failed RPC security service for NFS server

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.
1 loaded units listed.

# systemctl status rpc-svcgssd
* rpc-svcgssd.service - RPC security service for NFS server
      Loaded: loaded (/etc/systemd/system/rpc-svcgssd.service; static)
      Active: failed (Result: exit-code) since Wed 2021-12-29 14:00:51 CET; 8min ago
     Process: 301 ExecStart=/usr/sbin/rpc.svcgssd $SVCGSSDARGS (code=exited, status=1/FAILURE)
         CPU: 6ms

Dec 29 14:00:50 nfs00.example.com systemd[1]: Starting RPC security service for NFS server...
Dec 29 14:00:50 nfs00.example.com rpc.svcgssd[302]: ERROR: GSS-API: error in gss_acquire_cred(): GSS_S_FAILURE (Unspecified GSS failure.  Minor code may provide more information) - No key table entry found matching nfs/@
Dec 29 14:00:50 nfs00.example.com rpc.svcgssd[302]: unable to obtain root (machine) credentials
Dec 29 14:00:50 nfs00.example.com rpc.svcgssd[302]: do you have a keytab entry for nfs/<your.host>@<YOUR.REALM> in /etc/krb5.keytab?
Dec 29 14:00:51 nfs00.example.com systemd[1]: rpc-svcgssd.service: Control process exited, code=exited, status=1/FAILURE
Dec 29 14:00:51 nfs00.example.com systemd[1]: rpc-svcgssd.service: Failed with result 'exit-code'.
Dec 29 14:00:51 nfs00.example.com systemd[1]: Failed to start RPC security service for NFS server.
```

Shouldn't svcgssd either exit silently with 0 or become optional? Looking at
nfs(5) Kerberos authentication for NFS appears to be optional, regardless if
there is a keytab file with or without NFS credentials.


Regards

Harri

Hi

The rpc-svcgssd.service already has some conditionals:

ConditionPathExists=|!/run/gssproxy.pid
ConditionPathExists=|!/proc/net/rpc/use-gss-proxy
ConditionPathExists=/etc/krb5.keytab

If no /etc/krb5.keytab exists in fact the status will be

○ rpc-svcgssd.service - RPC security service for NFS server
     Loaded: loaded (/usr/lib/systemd/system/rpc-svcgssd.service; static)
     Active: inactive (dead)
  Condition: start condition failed at Tue 2021-12-21 10:28:53 CET; 1 week 1 day ago

If you have a /etc/krb5.keytab then the condition is met to try to start
rpc-svcgssd.

Regards,
Salvatore

Sure, but why does systemctl complain about rpc-svcgssd.service, if
there are no NFS credentials inside? Its perfectly fine to run NFS
without cryptographic security, even though /etc/krb5.keytab does
exist.

I have the impression that the conditionals you mentioned are not
complete.