Postgres launchd script suggestions

[Jyrki Wahlstedt]

On 7.6.2007, at 18.19, Christian Voelker wrote:

> Hello Markus and Jyrki,
>
> I am running PostgreSQL as built by macports since some time
> with great success (currently I have a little issue on a G5
> iMac, by I have to investigate that myself before screaming).
> Thank you for your porting efforts, package maintainance and
> fast response to updates!
>
Thanks!

> With every update, I have to replace one file manually with
> a slightly modified version though. I believe that my mods
> would not break anybodies installation but enhance the over-
> all experience in some cases. Thus, I have put together a
> little patch. Please discuss or integrate in case you decide
> that this is a good mod. Obviously, I myself would benefit
> the most from this ;-). the file in question is:
>
> /opt/local/etc/LaunchDaemons/org.macports.postgresql82-server/ 
> postgresql82-server.wrapper
>
> Here comes the patchfile. If the format does not fit your
> needs, please tell me how to do better or point me to a
> place telling how to do it.
>
> <postgresql82-server.wrapper.patch.unified>
>
The format is perfect.
>
> Some comments on the two issues I am addresing with my changes.
> First, the postgres user account. The Macs I am running Postgres
> on are also used interactively. The Login screen is set to list
> mode. Unlike other unix accounts created for use by daemons, the
> postgres account shows up in this list, which adds confusion to
> other users accessing this machine. This behaviour can be sup-
> pressed by setting the shell variable in the NetInfo database
> to /usr/bin/false as shown with many Apple supplied software.

The user account is something that needs some work. I agree that the  
user created here shouldn't be visible in different lists. However, I  
may be wrong, but I have thought that user visibility is governed by  
user ID that for most daemon users is less than 100 that is the  
horizon in this case. The id area below 100 is however Apple's area,  
so we can't create any id there.
I must admit that I use a slightly modified version of Portfile just  
to be sure that I don't create superfluous users. Maybe I am too  
cautious but I use a version that adds the user only if it does not  
exist already. This is not yet in the Portfile yet, maybe I have the  
wrong impression of how adduser command in Portfile works...
>
> The drawback of denying interactive login to such user accounts
> is in testing and boot scripts. A way around this is to call su
> with -m option which inherits the environment from root, which
> is the user account used by the invoking launchd service. I cant
> see this to be harmful unless you were used to setting environ-
> ment variables in another place then /etc/profile which I use for
> this purpose. Please note, that setting shell to /usr/bin/false
> could be done by your install scripts using niutil. This would
> be the next step in sophistication not shown in my patch.
>
>
> The other place of modification is a short hint to the user on
> how to set the environment variable POSTGRESQL82DATA to a value
> of their choice. I had to do this when I decided on my scheme for
> database backup. Actually, I keep the whole macports directory
> structure under /Library/Macports with fresh installs. I do this
> to avoid /opt showing up in the root directory. I feel in sync
> with Apples policy on places to install 3rd party software and
> with macports installing interactive apps such as Abiword in a
> folder called /Applications/Macports. I also keep working data
> of any installed additional services such as CVS in directories
> named /Library/Name_of_service to ease backup. Other users might
> decide to keep such data under /Users/Shared/ or wherever.
>
/opt is the place, I used /usr/local earlier, but changed that later.  
There is nothing wrong in creating subdirectories in /. Everybody has  
a way of work, and the tools should be adaptable.

> Lastly, I like to use Console.app to read Logfiles. Console.app
> comes prefconfigured with three directories in the side column,
> where to look for logfiles. These three folders seem to be hard
> wired, which might not be that smart from Apple, but which makes
> it barely usable for Logfiles burried deep inside the directory
> structure of macports. I feel users should be supported if they
> like to keep their Logfiles elsewhere. The three folders in the
> sidebar are (~)/Library/Logs and /var/log respectively. With the
> rationale mentioned above, I keep Logfiles under /Library/Logs/.
>
> I had to figure out myself, how to set POSTGRESQL82DATA without
> modifying the wrapper provided by you myself. I feel that every-
> body who tries to do so will come to this place and thus found
> this the right place for a comment. i also introduced a variable
> for the logging directory.
>
I use Console.app to read logfiles, too. There is no problem in  
making it read log files elsewhere in the system. I myself have  
Apache2 log files open from /opt/local/apache2/logs.
I am also not sure of copying a user's environment for port. This is  
perhaps a bit paranoid, but ports should reside in a totally  
controlled environment.

with best greetings,
Jyrki Wahlstedt