X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/582e52d3ca79d0d5d0335486718fe2167d6304cd..aa06b950eaa6bbdd20813ac08d4383219a09ab97:/doc/tips/Hosting_Ikiwiki_and_master_git_repository_on_different_machines.mdwn

diff --git a/doc/tips/Hosting_Ikiwiki_and_master_git_repository_on_different_machines.mdwn b/doc/tips/Hosting_Ikiwiki_and_master_git_repository_on_different_machines.mdwn
index e971a8339..6af4f9619 100644
--- a/doc/tips/Hosting_Ikiwiki_and_master_git_repository_on_different_machines.mdwn
+++ b/doc/tips/Hosting_Ikiwiki_and_master_git_repository_on_different_machines.mdwn
@@ -1,4 +1,5 @@
 [[!meta title="Hosting Ikiwiki with a master git repository on a remote machine"]]
+[[!meta date="2013-07-22 16:38:20 -0400"]]
 
 This tutorial explains how to set up a wiki such that:
 
@@ -17,6 +18,7 @@ I assume the [[rcs]] used is [[rcs/git]], but it might be done for other rcs.
 
 # Similar and related tips and problems
 
+- [[tips/distributed_wikis]] References different way of distributing wikis (including this one).
 - [[http://www.icanttype.org/blog/ikiwiki_git_remote_repo/]] Similar to what I
   am describing, excepted that you must be able to connect to the machine
   hosting Ikiwiki using ssh.
@@ -37,6 +39,8 @@ it on a remote machine, and tell Ikiwiki to use it instead of its local one. We
 will also ensure that the wiki is rendered whenever a commit is done to the git
 repository.
 
+[[!img separate-web-git-servers.svg size=400x]]
+
 # Conventions
 
 - We are building a wiki called *SITE*.
@@ -71,7 +75,7 @@ repository.
 ## Configuring the wiki on the wiki machine so that it uses the repository of the git machine
 
 - Configure ssh so that it uses the ssh key `id_SITE` to connect to the git
-  michine: add the following lines to file `~/.ssh/config` on the ikiwiki
+  machine: add the following lines to file `~/.ssh/config` on the ikiwiki
   machine:
 
         Host server.name.of.the.git.machine
@@ -119,21 +123,36 @@ repository.
 
 ## Configure the git repository (on the git machine) to update the wiki after a push
 
-- Add in the `post-receive` hook (file `SITE.git/hooks/post-receive`):
+Add in the `post-receive` hook (file `SITE.git/hooks/post-receive`):
+
+      git log -1 --format=format:%ae HEAD | grep -e '@web$' -e 'USER@HOST' ||  wget "http://WIKI-URL/ikiwiki.cgi?do=ping" -O /dev/stdout
 
-        wget "http://WIKI-URL/ikiwiki.cgi?do=ping" -O /dev/stdout
+If your wiki is password protected, use:
 
-  If your wiki is password protected, use:
+      git log -1 --format=format:%ae HEAD | grep -e '@web$' -e 'USER@HOST' ||  wget "http://LOGIN:PASSWORD@WIKI-URL/ikiwiki.cgi?do=ping" -O /dev/stdout
 
-        wget "http://LOGIN:PASSWORD@WIKI-URL/ikiwiki.cgi?do=ping" -O /dev/stdout
+The bit before `wget` is here to prevent updating the wiki while it is
+updating, which can lead to a deadlock. Indeed, when the wiki is edited via
+web, or a tag page is automatically added, IkiWiki pushes the changes to the
+Git machine. Then, the hook on this latter machine tries to pull changes from
+the IkiWiki machine, and here is the deadlock. Explanations of the command:
 
+* `git log -1 --format=format:%ae HEAD`: Looks for the user name of the
+  latest commit.
+* `grep -e '@web$' -e 'USER@HOST': Check whether this last commit was pushed
+  from the IkiWiki machine (change `USER@HOST` to the appropriate string).
+* `wget ...`: If the last commit does not come from the IkiWiki machine
+  (which means it comes from another machine), update the wiki.
 
 ## Going further
 
 - *Web server on a third machine* It should be possible to use a third machine
-  to host the web server. A hook might be used to export the rendered wiki on
-  this server, or use a nfs repository as the destination repository of
-  ikiwiki. However, allowing web modifications (using CGI) might be tricky…
+  to host the web server, using [[this documentation|tips/Git_repository_and_web_server_on_different_hosts/]].
 - *Using [[gitolite|https://github.com/sitaramc/gitolite]] to manage
   repositories on the git machine* Simply replace the manipulations of git on
   the git machine by the corresponding manipulations using gitolite.
+    * With gitolite, you can use this line in a `post-update` hook:
+
+        `[ x"$GL_USER" = x"`*`gitolite-user`*`" ] || wget ...` where *gitolite-user* is the name of the public key registered through gitolite.
+
+        Thus, you filter out precisely the events that originate from the server-to-be-pinged, no matter what the commit id says. (For example, if you push commits you created on a local CGI ikiwiki, they'd be called '@web' as well).