Re: [Libtirpc-devel] [PATCH rpcbind] Move default state-dir to /run/rpcbind

[NeilBrown <neilb@suse.com>]

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On Wed, Nov 16 2016, Steve Dickson wrote:

> On 11/15/2016 01:36 AM, NeilBrown wrote:
>> On Tue, Nov 15 2016, Steve Dickson wrote:
>>
>>> On 11/10/2016 10:36 PM, NeilBrown wrote:
>>>> rpcbind can save state in a file to allow restart without forgetting
>>>> about running services.
>>>>
>>>> The default location is currently "/tmp" which is an over-used
>>>> directory that isn't really suitable for system files.
>>>> The modern preferences would be a subdirectory of "/run", which can
>>>> be selected with a ./configure option.  That subdirectory would still need
>>>> to be created by something.
>>>>
>>>> It is trivial for rpcbind to create the directory itself, and harmless
>>>> to try if it already exists, so:
>>>> - add a "mkdir" when saving state data
>>>> - change the default to /run/rpcbind (currently used by Debian)
>>>> - remove the default settign in the code, just use the one
>>>>   in configure.ac
>>> I'm all for move the warmstart directory to /run but why don't we have systemd
>>> create the directory via a  tmpfiles.d( config file... some like
>>>
>>> #Type Path      Mode UID GID Age Argument
>>> D  /run/rpcbind 0700 rpc rpc - -
>>>
>>> The only thing I'm not sure about is how it would get installed...
>>> I guess it would some type of Makefile.ac entry??
>> Because not everyone uses systemd?
> Yeah... I figured as much.
>> Someone at SUSE recently moved the state directory to /run/rpcbind and
>> used tmpfiles.d exactly as you describe to create /run/rpcbind.  Then
>> found they needed to do something extra and different for dracut.  I
>> haven't looked into why, but it is presumably because while dracut does
>> use systemd, it doesn't use it quite the same way that normal system boot
>> uses it.
> I didn't have this problem when I move rpcbind in RHEL7 to use /run/rpcbind via tmpfiles.d
> The biggest problem I had was migrating the warmstart files to the new place.
> Having /run/rpcbind exist after boot made that much easier. 

That would be a bit fiddlely.
Might be easiest to create a symlink /run/rpcind -> old-location when
the package is installed, then let the proper directory be created on
boot.
Only then you cannot clean up the old directory at install time.

>> I've found this with configuring mdadm too.  I got the udev and systemd
>> configuration just right, and then found that while dracut uses udev and
>> systemd, I still need to add extra stuff to dracut.  And then there was
>> another boot environment which used udev but not systemd, so it needed
>> different tweaking.
>>
>> So I think we are less likely to run into strange problems if we just
>> get rpcbind to create its own directory.  Certainly rely on systemd to
>> do the things that systemd does best (like start the service), but don't
>> rely on it to do things we can easily do ourselves.
> Another potential problem is SElinux... Its never a fan of daemon creating things
> on the fly... but I guess that is my problem 8-)

rpcbind would only create the directory if it doesn't exist.  If you
need to create it with special SElinux things, there is no harm in doing
that first.

Thanks,
NeilBrown

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