ikiwiki/doc/post-commit/discussion.mdwn

Hi Joey and many thanks for your work on ikiwiki, as usual you give us a very good soft...

I want to be able to edit my website from a navigator (with the CGI) and
from my favorite editor on my laptop. I have managed to use the subversion wrapper
so I have write a post-commit hook with : 

    cd /~/wikisrc/ 
    svn up
    /usr/bin/ikiwiki --setup ../ikiwiki.setup

at the end.

This configuration works for me, the svn wrapper doesn't seems to
do the svn up stuff so I wonder if I've missed something...

Regards.

> Well, you've created a post-commit script that runs ikiwiki in setup mode.
> That's not how it's generally done, instead you generally configure
> ikiwiki to generate a post-commit _binary_ that runs ikiwiki in update
> mode. That binary can be installed directly as the post-commit hook, or
> called from an existing post-commit hook script, and it will handle the
> necessary svn up, and will update the wiki much quicker than your --setup
> command above (which rebuilds the entire wiki and all wrappers each
> commit)!
>
> In this wiki's setup file, I configure ikiwiki to generate a post-commit
> wrapper binary like so:
> 
> 	wrappers => [
> 	{
> 		wrapper => "/srv/svn/ikiwiki/hooks/post-commit",
> 		wrappermode => "04755",
> 		notify => 1,
> 	}
>	],


Hello, I've setup ikiwiki with subversion. I can edit pages from web browser using CGI and, when I go to recentchanges, it shows that modification with "web" word. But, if I modify any .mdwn file, it gets updated in website but it doesn't show in recentchanges entry with "svn" word. If I run "svn ci -m changes", it shows in recentchanges correctly.

So, I think I miss something, because I don't think I must run "svn add" or "svn commit" anytime I modify or create a wiki file.

Thanks

> Yes, ikiwiki does expect you to use your revision control system to check
> in changes. Otherwise, recentchanges cannot work right, since it uses the
> commit history from your revision control system. --[[Joey]]

-----

I'm working on an [[rcs]] plugin for CVS, adapted from `svn.pm`, in order
to integrate ikiwiki at sites where that's all they've got. What's working
so far: web commit (post-commit hook and all), diff, add (under certain
conditions), and remove. What's not working: with rcs_add(), iff any of the
new page's parent dirs aren't already under CVS control and the post-commit
hook is enabled, the browser and ikiwiki stall for several seconds trying
to add it, then time out. (If I kill ikiwiki when this is happening, it cvs
adds the topmost parent that needed adding; if I wait for timeout, it
doesn't. I think.) If I disable the post-commit hook and do the same kind
of thing, the page is created and saved.

In case you're lucky enough not to know, cvs adds on directories are weird
-- they operate immediately against the repository, unlike file adds:

    $ cvs add randomdir
    Directory /Users/schmonz/Documents/cvswiki/repository/ikiwiki/randomdir added to the repository

I was able to work out that when I'm seeing this page save misbehavior, my
plugin is somewhere inside `system("cvs", "-Q", "add", "$file")`, which was
never returning. If I changed it to anything other than cvs it iterated
correctly over all the parent dirs which needed to be added to CVS, in the
proper order. (cvs add isn't recursive, sadly.)

Can you offer an educated guess what's going wrong here? --[[Schmonz]]

> Got `rcs_recentchanges` working, believe it or not, thanks to [cvsps](http://www.cobite.com/cvsps/). If I can figure out this interaction between the post-commit hook and `cvs add` on directories, the CVS plugin is mostly done. Could it be a locking issue? Where should I be looking? Any suggestions appreciated. --[[Schmonz]]

>> Okay, it is definitely a locking issue. First, on the conjecture that
>> `cvs add <directory>` was triggering the post-commit hook and confusing
>> ikiwiki, I wrapped the ikiwiki post-commit binary with a shell script
>> that exited 0 if the triggering file was a directory. The first half of
>> the conjecture was correct -- my wrapper got triggered -- but the web
>> add of `one/two/three.mdwn` (where `one` and `two` weren't existing
>> CVS-controlled dirs) remained hung as before. There were two ikiwiki
>> processes running. On a whim, I killed the one with the higher PID; `cvs
>> add one` immediately completed successfully, then back to a hang and two
>> ikiwiki processes. I killed the newer one again and then `cvs add
>> one/two` and `cvs add one/two/three.mdwn` completed and the web add was
>> successful. --[[Schmonz]]

>>> Aaaaaand I was wrong about the second half of the conjecture being
>>> wrong. The wrapper script wasn't correctly identifying directories;
>>> with that fixed, everything works. I've created a
>>> [[plugins/contrib/cvs]] plugin page. Thanks for listening. :-)
>>> --[[Schmonz]]

>> Here is a comment I committed to my laptop from Madrid Airport before
>> your most recent updates, in case it's still useful:
>>
>> Locking certianly seems likely to be a problem. ikiwiki calls `rcs_add`
>> *before* disabling the post-commit plugin, since all over VCS allow
>> adding something in a staged manner. You can see this in, for example,
>> `editpage.pm` lines 391+.
>> 
>> So I guess what happens is that ikiwiki has taken the wiki lock, calls
>> `rcs_add`, which does a `cvs add`, which runs the post commit hook,
>> since it is not disabled -- which blocks waiting for the wiki lock.
>>
>> I guess you can fix this in either of three ways: Modify lots of places
>> in ikiwiki to disable the post commit hook before calling `rcs_add`,
>> or make cvs's `rcs_add` temporarily disable the commit hook and
>> re-enable it (but only if it was not already disabled, somehow),
>> or make cvs's `rcs_add` only make note that it needs to call `cvs add`
>> later, and do so at `rcs_commit`. The last of these seems easist,
>> especially since ikiwiki always commits after an add, in the same
>> process, so you could just use a temporary list of things to add.
>> --[[Joey]]