[Twisted-Python] untwisting twistd
glyph at divmod.com
glyph at divmod.com
Mon Jun 22 17:38:54 EDT 2009
On 09:06 pm, phil at bubblehouse.org wrote:
>On Jun 22, 2009, at 4:30 PM, Jared Gisin wrote:
>>Which is iditic as my application may not even expose a 13pidfile or
>>a 13logfile and it 19s definatley not called twistd. The platform
>>specific application runners need to be more generalized so users
>>can write their own twistd equivalent to include only what they want.
>Look at the init script used to start MySQL sometime, particularly
>when installed from a package on a finicky distro like debian. Or
>Apache. Or bind. Or any one of a number of other complex daemons --
>you'll find that it's not usually advisable (or possible) to launch
>any of these daemons without an endless list of command-line options.
Sure, but we should be able to do better than that, right? :)
>You said yourself that you should be able to write a python script
>that functions in a certain way, but what makes you think it should be
>integrated into twistd? You could write a wrapper that made use of the
>many other convenient scripting features Twisted provides (such as
>twisted.python.usage.Options) and which would then in turn launch the
>twistd process with the arguments you require, much like MySQL's
>mysqld_safe bootstrap utility.
Actually, it's even simpler than that. The script is itself a function,
which you can just call as a function without starting a separate
process. Axiom had requirements like Mr. Gisin: we wanted to put the
.pid file and log files inside the database directory, which is a
location that obviously has to be computed.
I wouldn't object to a more graceful and structured way to do this, but
the approach "axiomatic" uses is pretty simple: provide a twistd plugin
that does the meat of the work, then have a small wrapper script that
builds a command line that includes the plugin and the appropriate
options, such as logfile and pidfile.
You can see that code here:
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