1Subject: [HOWTO] Using post-update hook 2Message-ID: <7vy86o6usx.fsf@assigned-by-dhcp.cox.net> 3From: Junio C Hamano <gitster@pobox.com> 4Date: Fri, 26 Aug 2005 18:19:10 -0700 5Abstract: In this how-to article, JC talks about how he 6 uses the post-update hook to automate Git documentation page 7 shown at http://www.kernel.org/pub/software/scm/git/docs/. 8Content-type: text/asciidoc 9 10How to rebuild from update hook 11=============================== 12 13The pages under http://www.kernel.org/pub/software/scm/git/docs/ 14are built from Documentation/ directory of the git.git project 15and needed to be kept up-to-date. The www.kernel.org/ servers 16are mirrored and I was told that the origin of the mirror is on 17the machine $some.kernel.org, on which I was given an account 18when I took over Git maintainership from Linus. 19 20The directories relevant to this how-to are these two: 21 22 /pub/scm/git/git.git/ The public Git repository. 23 /pub/software/scm/git/docs/ The HTML documentation page. 24 25So I made a repository to generate the documentation under my 26home directory over there. 27 28 $ cd 29 $ mkdir doc-git && cd doc-git 30 $ git clone /pub/scm/git/git.git/ docgen 31 32What needs to happen is to update the $HOME/doc-git/docgen/ 33working tree, build HTML docs there and install the result in 34/pub/software/scm/git/docs/ directory. So I wrote a little 35script: 36 37 $ cat >dododoc.sh <<\EOF 38 #!/bin/sh 39 cd $HOME/doc-git/docgen || exit 40 41 unset GIT_DIR 42 43 git pull /pub/scm/git/git.git/ master && 44 cd Documentation && 45 make install-webdoc 46 EOF 47 48Initially I used to run this by hand whenever I push into the 49public Git repository. Then I did a cron job that ran twice a 50day. The current round uses the post-update hook mechanism, 51like this: 52 53 $ cat >/pub/scm/git/git.git/hooks/post-update <<\EOF 54 #!/bin/sh 55 # 56 # An example hook script to prepare a packed repository for use over 57 # dumb transports. 58 # 59 # To enable this hook, make this file executable by "chmod +x post-update". 60 61 case " $* " in 62 *' refs/heads/master '*) 63 echo $HOME/doc-git/dododoc.sh | at now 64 ;; 65 esac 66 exec git-update-server-info 67 EOF 68 $ chmod +x /pub/scm/git/git.git/hooks/post-update 69 70There are four things worth mentioning: 71 72 - The update-hook is run after the repository accepts a "git 73 push", under my user privilege. It is given the full names 74 of refs that have been updated as arguments. My post-update 75 runs the dododoc.sh script only when the master head is 76 updated. 77 78 - When update-hook is run, GIT_DIR is set to '.' by the calling 79 receive-pack. This is inherited by the dododoc.sh run via 80 the "at" command, and needs to be unset; otherwise, "git 81 pull" it does into $HOME/doc-git/docgen/ repository would not 82 work correctly. 83 84 - The stdout of update hook script is not connected to git 85 push; I run the heavy part of the command inside "at", to 86 receive the execution report via e-mail. 87 88 - This is still crude and does not protect against simultaneous 89 make invocations stomping on each other. I would need to add 90 some locking mechanism for this.