Re: Adding operating-system field for a custom /etc/profile.

[Alex Kost]

宋文武 (2015-11-24 18:22 +0300) wrote:

> On 2015-11-24 04:07, Alex Kost wrote:
>> This is a continuation of the discussion beginning here:
>> <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=20255#44>.
>>
>> To sum up: I would like to have a possibility to use my own
>> /etc/profile
>> instead of the default one, but Ludovic doesn't want to provide me this
>> freedom :-(
> Well, every comment in /etc/profile came with a hack which make
> something work.  but it's becomming big and hard to understand every
> line.

Sorry, I don't understand what you want to say.  I'm able to make my own
/etc/profile based on the default one, and I just want to have an option
to do it.

>> Ludovic Courtès (2015-11-23 17:31 +0300) wrote:
>>
>>> Hmm, I’m not sure if we want to give direct access to /etc/profile
>>> like
>>> this.
>>
>> Oh, no!  If there is one person (me) who wants to have a full control
>> on
>> his /etc/profile, there may be the others with the same wish.
> Sure, I think we all want (and should have) a full control.

Yes, unluckily GuixSD does not provide such control currently.

[...]
>>> The risk I see with adding a raw ‘profile-file’ option is that
>>> newcomers
>>> may end up getting rid of such things without really noticing, and
>>> then
>>> getting a broken system.
>>
>> But a newcomer will learn about this option only if (s)he reads the
>> manual with the warning I've mentioned.  For me, your phrase sounds
>> like: «We will not provide "rm" command, because a newcomer may
>> accidentally run "rm -rf ~"».  Please give me an opportunity to shoot
>> myself in the foot!
>>
>> Besides will the system really be broken?  What do you mean?  Even if
>> /etc/profile is empty, the system will boot successfully and a user
>> could login, no?
> Yes, login works, but then /run/current-system/profile/bin isn't in
> PATH, and some system configurations (eg: locale, timezone) are ignored.

Yes, but we are talking about an optional thing, that should be
explicitly set by a user, so I don't really understand concerns about
the potential risk, as a user will learn about this option at first
before using it.

>>> What about instead giving a way to populate the top and/or bottom of
>>> this file?  Controversial parts, if any, could still be turned on and
>>> off by adding or removing services that add these lines?
>>
>> It is better than nothing, but it is not sufficient IMO.  Any part of
>> /etc/profile can be controversial (you'll never know what a user would
>> like to change), so I think providing an option to change this file
>> completely is essential.
> To be clear, /etc/profile contains 3 parts:
>
>  1. variables from configuration of the operating-system (LANG, TZ,
> etc.)
>  2. environment setup for system and user profiles
>     (source .guix-profile/etc/profile)
>  3. hacks for making sensible defaults (LINUX_MODULE_DIRECTORY,
>     ASPELL_CONF, etc).
>
> And it's only effective for POSIX login shells (bash and zsh).
>
> For 1, maybe the most important one, it's already managed, but doesn't
> work for fish and rc.  We need to move these into /etc/environment,
> which work for all shells (even emacs? :-)

I didn't know about /etc/environment.  So IIUC it is used for VAR=VALUE
pairs, right?  If so and if it is supported by all shells (I don't see a
mention of it in the bash manual though), I agree with you to move these
things, great idea!

> For 2, we had build a etc/profile file for each profile's search-paths,
> here source both system and user to make most things work
> out-of-the-box.
>
> I think this is the real purpose for our /etc/profile.
> Technical, if we remove those, the result system will be the same as
> guix on foreign distros.  So, it's ok to completely replace it.
>
> (some variables (eg: MANPATH, INFOPATH, XDG_DATA_DIRS) can be set in
> each profile, and mergerd well).

IIUC invoking "guix package --search-paths" on both system and user
profiles sets all required environment variables, so sourcing
/run/current-system/profile/etc/profile and ~/.guix-profile/etc/profile
is not needed, right?

> And 3, IMO is the controversial parts.
>
> the one don't related to profiles can go into /etc/environment
> (eg: LINUX_MODULE_DIRECTORY, SSL_CERT_DIR, DBUS_FATAL_WARNINGS),
> these need to be addressing by adding services?

I agree that it's better to put plain VAR=VAL to /etc/environment.

> and others may go into profile (eg: ASPELL_CONF, GST_PLUGIN_PATH).

Yes.  And this is another example of the thing I want to change: I don't
like to have any mention of "$HOME/.guix-profile" in /etc/profile, so I
would remove these things it if had a chance.

> So, the plan is add /etc/environment and only use /etc/profile for 2.
> then, a sh-profile file-like configuration can be added.  WDYT?

I like the idea of separating /etc/environment and /etc/profile, but my
main concern is to have a possibility to change /etc files the way I
want, as I explained in the reply to Ludovic.

-- 
Alex