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

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

In this document:

  * <a href="#_NAME">NAME</a>
  * <a href="#_DESCRIPTION">DESCRIPTION</a>
  * <a href="#_EXAMPLE_ENVIRONMENT">EXAMPLE ENVIRONMENT</a>
  * <a href="#_GITOLITE_SETUP">GITOLITE SETUP</a>
      * <a href="#_gitolite_rc">gitolite.rc</a>
      * <a href="#_gitolite_conf">gitolite.conf</a>
  * <a href="#_APACHE_SETUP">APACHE SETUP</a>
      * <a href="#_suexec">suexec</a>
      * <a href="#_Gitweb">Gitweb</a>
      * <a href="#_Virtual_Host">Virtual Host</a>
  * <a href="#_VALIDATION">VALIDATION</a>
  * <a href="#_ADDITIONAL_RESOURCES">ADDITIONAL RESOURCES</a>
  * <a href="#_AUTHOR">AUTHOR</a>

<a name="_NAME"></a>

### NAME

gitolite-gitweb-http-backend

<a name="_DESCRIPTION"></a>

### 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.

<a name="_EXAMPLE_ENVIRONMENT"></a>

### 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:&lt;repo-name&gt;
      * http://git.example.com/&lt;repo-name&gt;.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

<a name="_GITOLITE_SETUP"></a>

### GITOLITE SETUP

Install gitolite via your package management tools.  Under OpenSuSE, this will
install repositories in `/srv/git`.  Follow the instructions found [here][1in]
for initial set up.

[1in]: http://sitaramc.github.com/gitolite/doc/1-INSTALL.html

<a name="_gitolite_rc"></a>

#### 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.

<a name="_gitolite_conf"></a>

#### 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][conf].

[conf]: http://sitaramc.github.com/gitolite/doc/gitolite.conf.html

<a name="_APACHE_SETUP"></a>

### 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`?

<a name="_suexec"></a>

#### 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`.

<a name="_Gitweb"></a>

#### 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`!

<a name="_Virtual_Host"></a>

#### 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>

<a name="_VALIDATION"></a>

### 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

<a name="_ADDITIONAL_RESOURCES"></a>

### ADDITIONAL RESOURCES

- [http://httpd.apache.org/docs/2.2/suexec.html](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](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](https://git.wiki.kernel.org/index.php/Gitweb) git-web documentaiton
- [http://sitaramc.github.com/gitolite/doc/http-backend.html](http://sitaramc.github.com/gitolite/doc/http-backend.html) gitolite http backend documentation

<a name="_AUTHOR"></a>

### AUTHOR

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