gitolite/doc/gitolite-gitweb-http-backend.mkd

how to set up gitolite+gitweb+ssh+http-backend

In this document:

• NAME
• DESCRIPTION
• EXAMPLE ENVIRONMENT
• GITOLITE SETUP
  • gitolite.rc
  • gitolite.conf
• APACHE SETUP
  • suexec
  • Gitweb
  • Virtual Host
• VALIDATION
• ADDITIONAL RESOURCES
• AUTHOR

NAME

gitolite-gitweb-http-backend

DESCRIPTION

You've been tasked with rolling out gitolite and git-web in your corporate environment and your requirements are as follows:

1. git access must be via both ssh and http[s]
2. browsable via git-web
3. your web server must run as a user different from that of the git user
4. The repository has its own virtual host

Note that these instructions are geared toward OpenSuSE 11.4. Feel free to modify the examples below to your environment.

EXAMPLE ENVIRONMENT

The following assumptions are made for the purposes of example:

• The server name will be git.example.com

• Repositories are located in /srv/git and are owned by the git user

• Apache 2.2.* running as wwwrun:www will be used as the web server

• gitolite has been installed via package management (yum, zypper, apt-get, etc)

• gitweb browsing is via http://git.example.com/

• The repositories can be cloned from the following URLs:

  • git@git.example.com:<repo-name>
  • http://git.example.com/<repo-name>.git

• HTTP authentication is handled via a local htpasswd file

• http://git.example.com will be a virtual host

• Two git repositories will be created:

  • engineering
  • operations

GITOLITE SETUP

Install gitolite via your package management tools. Under OpenSuSE, this will install repositories in /srv/git. Follow the instructions found here for initial set up.

gitolite.rc

You will need to tell gitolite.rc about some additional keys that will be needed for each repository. Make sure the following config option is set in /srv/git/.gitolite.rc:

$GL_GITCONFIG_KEYS = "gitweb.url receive.denyNonFastforwards receive.denyDeletes";

These options tell gitolite to allow the user to set these values in gitolite.conf, which in turn will be propagated to each repositories git config.

gitolite.conf

For the purposes of example, we assume that we have two groups accessing each repository: engineering and operations. So, our gitolite.conf file will look something like this:

#
# Group Definitions
#

@engineering  = daniel erik alex jose mark
@operations   = james chris long bora dmitriy
@gladmin      = james chris

#
# Repository Definitions
#

repo    gitolite-admin
        RW      =   @sysops daemon
        R       =   @all

repo    engineering
        RW      = @engineering @gladmin daemon
        R       = @all
        config  gitweb.url                  = git@git.example.com:engineering
        config  receive.denyNonFastforwards = true
        config  receive.denyDeletes         = true

repo    operations
        RW      = @operations @engineering @gladmin daemon
        R       = @all
        config  gitweb.url                  = git@git.example.com:engineering
        config  receive.denyNonFastforwards = true
        config  receive.denyDeletes         = true

repo    @all
        R       =   daemon gitweb

# additional configuration ...

Save, commit, and push your changes to the gitolite-admin repo as described here.

APACHE SETUP

Under OpenSuSE 11.4, Apache runs as user wwwrun group www (see /etc/apache2/uid.conf). But wait! How can Apache running as wwwrun commit to git repositories, which are owned by git?

suexec

Enter SuExec. This is an apache module that allows apache to run under the auspicious of a different user. For this to work, we need to do some setup ahead of time. First, we need to make sure the suexec program has the right permissions:

# OpenSuSE 11.4 puts the suexec program under /usr/sbin/suexec2
$ chgrp www /usr/sbin/suexec2
$ chmod 4750 /usr/sbin/suexec2

# Verify permissions
$ ls -al /usr/sbin/suexec2
-rwsr-x--- 1 root www 14944 Feb 18 20:53 /usr/sbin/suexec2

Next, we need to create a wrapper script for the suexec program and place that under the correct directory. To find out the where to place the wrapper script, do the following:

$ /usr/sbin/suexec2 -V
 -D AP_DOC_ROOT="/srv/www"
 -D AP_GID_MIN=96
 -D AP_HTTPD_USER="wwwrun"
 -D AP_LOG_EXEC="/var/log/apache2/suexec.log"
 -D AP_SAFE_PATH="/usr/local/bin:/usr/bin:/bin"
 -D AP_UID_MIN=96
 -D AP_USERDIR_SUFFIX="public_html"

The variable we are interested in is AP_DOC_ROOT which is /srv/www. So, we place the wrapper script in /srv/www/bin/gitolite-suexec-wrapper.sh with the following contents:

#!/bin/bash

#
# Wrapper for gl-auth-command
#

USER=$1

export GIT_PROJECT_ROOT="/srv/git/projects"
export GITOLITE_HTTP_HOME="/srv/git"

# OpenSuSE gitolite RPM places gl-auth-command in /usr/bin
exec /usr/bin/gl-auth-command $USER

# End

For security purposes, this file MUST exist under /srv/www!

Finally, make sure Apache loads the suexec module. Under OpenSuSE, this would mean adding "suexec" to APACHE_MODULES in /etc/sysconfig/apache2.

Gitweb

As gitweb will now be run under the git user, all files must be under /srv/www as well.

# Under OpenSuSe, git-web installs in /usr/share/gitweb
$ cp -r /usr/share/gitweb /srv/www
$ chown -R git.git /srv/www/gitweb

Do not forget to point $projectroot in /etc/gitweb.conf to /srv/git/projects!

Virtual Host

Configure your virtual host as follows:

<VirtualHost git.example.com:80>

    ServerName  git.example.com
    ServerAlias git

    # By default, use gitweb
    DocumentRoot /srv/www/gitweb

    # Suexec setup
    SuexecUserGroup git git

    # Set up appropriate GIT environments
    SetEnv GIT_PROJECT_ROOT /srv/git/projects
    SetEnv GIT_HTTP_EXPORT_ALL

    # Set up appropriate gitolite environment
    SetEnv GITOLITE_HTTP_HOME /srv/git

    # To serve gitweb at the same url, use a ScriptAliasMatch to
    # only those URLs that git http-backend can handle, and
    # forward the rest to gitweb:
    ScriptAliasMatch \
            "(?x)^/(.*/(HEAD | \
                            info/refs | \
                            objects/(info/[^/]+ | \
                                     [0-9a-f]{2}/[0-9a-f]{38} | \
                                     pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
                            git-(upload|receive)-pack))$" \
            /srv/www/bin/gitolite-suexec-wrapper.sh/$1

    # Make sure we can execute gitweb okay
    <Directory "/srv/www/gitweb">
            Options ExecCGI
            AllowOverride None
            AddHandler cgi-script .cgi
            DirectoryIndex gitweb.cgi
            Order allow,deny
            Allow from all
    </Directory>

    # We need gl-auth-command executable
    <Directory "/srv/www/gitbin">
            <Files "gitolite-suexec-wrapper.sh">
                    Order allow,deny
                    Allow from all
            </Files>
    </Directory>

    # Set up authentication to taste
    <Location />
               AuthType Basic
               AuthName "Private Git Access"
               Require valid-user
               AuthUserFile /srv/git/passfile
    </Location>

</VirtualHost>

VALIDATION

Once apache has been restarted, verify your configuration:

• Repository browsable via gitweb
• Check out repository via ssh
• Check out repository via http
• Commit over ssh git@git.example.com
• Commit over http

ADDITIONAL RESOURCES

• http://httpd.apache.org/docs/2.2/suexec.html Apache suexec documentation
• http://www.kernel.org/pub/software/scm/git/docs/git-http-backend.html git-http-backend(1) documentation
• https://git.wiki.kernel.org/index.php/Gitweb git-web documentaiton
• http://sitaramc.github.com/gitolite/doc/http-backend.html gitolite http backend documentation

AUTHOR

Christopher M. Fuhrman << cfuhrman at panix dot com >>