On 10/1/07, Ryan Schmidt <ryandesign@macports.org> wrote:
On Oct 1, 2007, at 17:52, paul beard wrote:

> On 10/1/07, Ryan Schmidt wrote:
>

Yes, we do want MacPorts to install as much as possible inside $
{prefix}. But currently some things do get installed outside of the
prefix. But IMHO the current uninstall instructions adequately
address this issue. BTW, "rm -rf /opt/local" is not the extent of the
uninstall instructions:

Um, yes, I realize that. Allow the possibility that someone will just do rm -rf /opt/local when they get stuck without realizing that they are leaving some cruft behind.  

> And as for invoking launchct load statements, how is this different?
>
> launchctl  load /opt/local/etc/LaunchDaemons/org.macports.dbus/
> org.macports.dbus.plist
> launchctl  load /opt/local/etc/LaunchDaemons /org.macports.apache2/
> org.macports.apache2.plist
> launchctl  load /opt/local/etc/LaunchDaemons/org.macports.mysql5/
> org.macports.mysql5.plist
>
> from putting the plists in launchd's default search path? As
> configured, launchctl looks in two places for plists: in /System/
> Library/LaunchDaemons, for Apple-owned stuff, in /Library/
> LaunchDaemons for user-installed/third-party stuff. I don't see a
> big deal about another repository for plists. Maybe in future
> releases launchd will allow additional directories to be added
> instead of individual lines.
>
>> Your way would require someone to manually edit the file /etc/
>> launchd.conf, at least to remove a line from it. That's more
>> complicated than the current way, where a single launchctl line
>> starts or stops the service. Also, with your way, the service
>> wouldn't start or stop until the next startup. That's worse than what
>> we have now, where the service starts or stops immediately.
>
> see above: if launchctl works as it says on the tin, there is not
> different between symlinks that point to /Library/LaunchDaemons and
> the lines I have in /etc/launchd.conf.

Wait. Currently, MacPorts automatically puts the symlinks in /Library/
LaunchDaemons, then instructs you how to load (start) and unload
(stop) as needed. Your proposition as I understood it was that the
user would manually add and remove lines in /etc/launchd.conf. Are
you now suggesting instead that MacPorts would automatically put the
lines in /etc/launchd.conf? If so, why is that preferable to the
current way? Currently, we add symlinks in /Library/LaunchDaemons,
which is outside of ${prefix}. You propose modifying /etc/
launchd.conf, which is also outside of ${prefix}. At least the
symlinks in /Library/LaunchDaemons have "macports" in the filenames
so they're easier to find, and getting rid of them is as simple as a
single "rm" command. Getting rid of a line in a conf file is more
involved.

 
Easy to find if someone knows to look for them. 

Also, since I'm not familiar with /etc/launchd.conf, I assume that
the file is only scanned at system startup. Is that the case? If so,
then adding to that file is worse than what we have now, where
"launchctl load" will load the service immediately, and cause it to
start at every subsequent system startup. Unless you're suggesting
that the user should modify /etc/launchd.conf, and then also use the
launchctl command to start the service now. If so, you've just added
an extra step for the user, again for no apparent benefit.

man launchd.conf? 

if you understand how launchd/launchctl works, you would know that a launchctl load statement means "load this plist file and do what it says until instructed otherwise." It doesn't matter if it's loaded on the command line or at boot time: once the instructions are loaded, they stay there. 

>> Running a single launchctl command to start or stop a service is
>> easy. Conversely, adding a line to a file is easy, as you showed, but
>> removing a line from a file requires a more elaborate script. So why
>> change it to make it more difficult?
>
> I'm not arguing in favor of it. I'm just explaining it.  I have a
> hard time believing that, given the power on tap, that there is no
> way to add a commented line to /etc/launchd.conf
>
> launchctl  load /opt/local/etc/LaunchDaemons/org.macports.dbus/
> org.macports.dbus.plist # installed by macports
>
>
> and add a # character to the beginning of the line containing the
> comment:
>
> sed -e s/^launchctl/#&/g <-  yes, I know that won't work, but you
> get the idea: sed is not my native language.

Yes, of course it's possible to write something with sed or similar
that adds or removes a specific line from a file. My point is that
it's more difficult than executing a single launchctl statement. And
since the current way works, I didn't understand why you think it's
better to complicate things.

Perhaps I don't think it's complicated. It's not clear that the other way works optimally.  The process of starting up daemons since Tiger is a departure and for a lot of people it doesn't always work properly (check the subject line of this thread and see if there are any others similarly named in the archives). 

What I'm hearing is "this way works because I understand it, and I don't understand your way. Different == bad." I really don't care what anyone uses. I found a way that works for me, even if it repeats steps that MacPorts already does. 

>> There's a slight problem with the current way. If the service is
>> running at the time that you uninstall the port, the software stays
>> running. And if the service is running at the time that you upgrade
>> the port, the old version stays running and the new version's plist
>> says the software isn't running and it's inconvenient to fix that
>> (manually edit the plist to show that the software is running,
>> launchctl unload the software, launchctl load it again). Would your
>> new way solve either of these problems? (I haven't tried so I don't
>> know.)
>
> Is there no pre-install step that could stop the service with the
> existing plist, install, restart?

I don't think MacPorts should be stopping or starting any services
automatically. That could be unexpected and bad.

Hmm. Sounds like that was what you were asking for. I think upgrading a process and having it stopped and *not* restarted is worse. I have my FreeBSD installation set to restart any process for which an rc script is installed.  

So at upgrade time, stop the process with its plist file, do the upgrade, then let the administrator know that the port is upgraded and not running, with the requisite launchctl instruction to start it. Conversely, I would make automatically starting upgraded daemons an option for people in high-availability environments. 

I've been meaning to submit bug reports about these situations but
hadn't gotten around to it yet.

> Again, I'm not arguing in favor of doing it this way, I'm just
> explaining it. Perhaps if it's more clearly understood, a
> comparison can be made.

Ok. Then I'll say that I acknowledge that MacPorts could do it your
way instead of how it does it now, but I don't see any advantage to
making that change at this point, rather I currently see
disadvantages, so I don't think MacPorts should change this right
now, until someone shows why it's better.

Again, I simply offer this an alternative way that leverages the launchd/launchctl infrastructure. 

I'm done with this thread. It's diverged quite a bit and not very productively. 

 
--
Paul Beard / www.paulbeard.org/
< paulbeard@gmail.com/paulbeard@mac.com>