[Fedora-packaging] SCL discussion at yesterday's meeting, easy stuff

[Ralf Corsepius]

On 11/05/2013 04:42 PM, Toshio Kuratomi wrote:
> On Tue, Nov 05, 2013 at 04:34:47PM +0100, Honza Horak wrote:
>> On 11/01/2013 08:28 PM, Toshio Kuratomi wrote:
>>> A straw poll was taken about the filesystem location of SCLs.  A few FPC
>>> members were willing to use /opt but others were heavily opposed to it.
>>> Everyone was okay with using /usr/scl (or the plural form /usr/scls).  So
>>> I think that needs to become the scl root dir (is that the right term?) for
>>> Fedora.
>>>
>>> FPC was okay with the idea that third parties might use /usr/scl as well.
>>> I didn't bring this up at the meeting but one thing that influences me on
>>> this is that scls are inherently rpm managed and therefore mixing both our
>>> scls with third party scls does not seem like the same vendor-OS problem
>>> that /opt was designed to fix.
>> I feel the need to add my POV about choosing /usr/scl for SCL prefix.
>> FHS states: "/usr is the second major section of the filesystem. /usr
>> is shareable, read-only data. That means that /usr should be
>> shareable between various FHS-compliant hosts and must not be written
>> to. Any information that is host-specific or varies with time is
>> stored elsewhere." [1]
>>
>> That seems to me like a no-go for having /usr/scl as a prefix for
>> SCLs, because there surely are packages that need to write some
>> files, probably not only databases. So I'd also vote for /opt since
>> there are no such requirements.
>>
>> [1] http://www.pathname.com/fhs/pub/fhs-2.3.html#THEUSRHIERARCHY
>>
> Although I favor /opt, this is not one of the reasons.  Our interpretation
> of /opt is that we also cannot depend on it being read-write and
> host-specific.  It looks like fhs developed /opt to be a vendor-friendly
> version of /usr.
In my understanding, this is exactly what you want (/opt/fedora or 
may-be /opt/scl/<more>)

>    Therefore it is also read-only and shareable.  The
> reasoning stems from FHS's decision to separate read-write and host-specific
> information from /opt:
>
> """
> Package files that are variable (change in normal operation) must be
> installed in /var/opt. See the section on /var/opt for more information.
>
> Host-specific configuration files must be installed in /etc/opt. See the
> section on /etc for more information.
> """
>
> http://www.pathname.com/fhs/pub/fhs-2.3.html#OPTADDONAPPLICATIONSOFTWAREPACKAGES
>
> As stated in my Filesystem Location Part 2 email:
> https://lists.fedoraproject.org/pipermail/packaging/2013-November/009717.html
>
> "we also noted that no matter whether /usr or /opt was used, config files
> would still need to be placed somewhere under /etc and state files somewhere
> under /var."
Correct - What is you problem with this?

Ralf