gitolite/doc/http-backend.mkd

# F=http how to setup gitolite to use smart http mode

**Note**: "smart http" refers to the feature that came with git 1.6.6, late
2009 or so.  The base documentation for this is `man git-http-backend`.  Do
**NOT** read `Documentation/howto/setup-git-server-over-http.txt` and think
that is the same or even relevant -- that is from 2006 and is quite different
(and arguably obsolete).

## WARNINGS, plus stuff I need help with

  * I have NOT converted the test suite to use this mode.  Volunteers to
    convert it to http access are welcome :-)

  * I have no idea how to handle the password issue other than creating a
    `~/.netrc` file and making it `chmod 600`.  Anyway, http based access is
    inherently less secure than pubkeys so not much point worrying about it.

  * I have not tested any of the ancillary standalone programs (like
    gl-admin-push) in this mode.  They're most likely going to crash and burn
    because `$HOME` is not defined or in the wrong place; manually set
    `HOME=$GITOLITE_HTTP_HOME` and hope for the best.  Luckily most of them
    have to do with sshkeys so this may not matter.  YMMV.

  * tested on stock Fedora 14; if you test on other environments please let me
    know how it worked out and if we need to adjust this document

  * tested https with dummy certs and `GIT_SSL_NO_VERIFY`; no reason why it
    shouldn't work on a proper setup with everything in place

  * have not tried making repos available to both ssh *and* http mode clients;
    (I'd guess it ought to work fine if the "apache" user was made login-able
    and given a proper $HOME and `~/.ssh/authorized_keys` and all that).  If
    anyone has the energy to try that please let me know how that went.

## additional requirements

  * requires `GIT_PROJECT_ROOT` (see "man git-http-backend" for what this is)
    set explicitly (i.e., it is no longer optional).  Please set it to some
    place outside apache's `DOCUMENT_ROOT`.

## detailed instructions

I assume you've installed apache 2.x and git on the server.

I assume your httpd runs under the "apache" userid; adjust instructions below
if it does not.  Similarly for "/var/www" and other file names/locations.

I assume you have read the "[please read this first][insttrouble]" section of the
main install document to get an idea of the general concepts and terminology
(just ignore anything that is specific to ssh).

### install gitolite under "apache"

Follow the "non-root" method, but since you can't even "su - apache", make the
following variations when doing this as root:

  * `cd ~apache` first; this is `/var/www` on Fedora 14

  * do this in the shell

        mkdir gitolite-home
        export GITOLITE_HTTP_HOME
        GITOLITE_HTTP_HOME=/var/www/gitolite-home
        PATH=$PATH:$GITOLITE_HTTP_HOME/bin

  * now run the following commands.  These are really the first 3 steps of the
    "non-root" install (clone, mkdir, and gl-system-install), **except** you
    substitute `GITOLITE_HTTP_HOME` in place of `HOME`.  Note that you do NOT
    run the gl-setup step yet.

        cd gitolite-home
        git clone /tmp/gitolite.git gitolite-source
            # or wherever your local clone is, or directly from git://github.com/sitaramc/gitolite

        cd gitolite-source
        GHH=$GITOLITE_HTTP_HOME     # just for convenience in next 2 commands
        mkdir -p              $GHH/bin $GHH/share/gitolite/conf $GHH/share/gitolite/hooks
        src/gl-system-install $GHH/bin $GHH/share/gitolite/conf $GHH/share/gitolite/hooks

  * after the gl-system-install step, add these to the **top** of
    /var/www/gitolite-home/share/gitolite/conf/example.gitolite.rc

        $ENV{GIT_HTTP_BACKEND} = "/usr/libexec/git-core/git-http-backend";
            # or wherever you have that file; note: NO trailing slash
        $ENV{PATH} .= ":$ENV{GITOLITE_HTTP_HOME}/bin";
            # note the ".=" here, not "="

  * run gl-setup with the name of your admin user

        gl-setup sitaram

  * IMPORTANT: fix up ownerships

        chown -R apache.apache $GITOLITE_HTTP_HOME

### setup apache

You will need to setup certain values in the httpd conf, as given in `man
git-http-backend`.  You can put all them into, for instance,
`/etc/httpd/conf.d/gitolite.conf` and apache [at least on Fedora 14] will pick
it up.  These are the values to use; note that these are somewhat different
from those in the manpage cited above, plus we have one extra variable:

    SetEnv GIT_PROJECT_ROOT /var/www/gitolite-home/repositories
    SetEnv GIT_HTTP_EXPORT_ALL
        # please see notes below on ssh+http access
    ScriptAlias /git/ /var/www/gitolite-home/bin/gl-auth-command/
        # note trailing slash

    SetEnv GITOLITE_HTTP_HOME /var/www/gitolite-home

    <Location /git>
        AuthType Basic
        AuthName "Private Git Access"
        Require valid-user
        AuthUserFile /path/to/some/passwdfile
    </Location>

Now create/update the password file in `/path/to/some/passwdfile` using the
`htpasswd` command, and you're all done for the setup!

## usage

Git URLs look like `http://user:password@server/git/reponame.git`.

The custom commands, like "info", "expand" should be handled as follows.  The
command name will come just after the `/git/`, followed by a `?`, followed by
the arguments, with `+` representing a space.  Here are some examples:

    # ssh git@server info
    curl http://user:password@server/git/info
    # ssh git@server info repopatt
    curl http://user:password@server/git/info?repopatt
    # ssh git@server info repopatt user1 user2
    curl http://user:password@server/git/info?repopatt+user1+user2

It gets even more interesting for the `setperms` command, which expects STDIN.
I didn't want to get too much into the code here, so I found that the
following works and I'm leaving it at that:

    (echo R user1 user2; echo RW user3 user4) |
        curl --data-binary @- http://user:password@server/git/setperms?reponame.git

With a few nice shell aliases, you won't even notice the horrible convolutions
here ;-)

## allowing anonymous access

Like [mob branches][mob] with ssh, you can allow completely
**un**-authenticated users to still have some rights specified in gitolite.
Briefly, here's how:

  * specify a ScriptAlias in apache config for unauthenticated access also.  I
    prefer something like

        ScriptAlias /gitmob/ /var/www/gitolite-home/bin/gl-auth-command/

  * set `$GL_HTTP_ANON_USER` to some name, like 'mob' or 'anon' in the rc file

  * give rights to this user ('mob' or 'anon' or whatever you used) in the
    gitolite config file and push the change

URLs (in this example) will then look like `http://server/gitmob/reponame.git`
-- we lose the userid:passwd part and change 'git' to 'gitmob'.

## ssh + http access and the `GIT_HTTP_EXPORT_ALL` variable

This document only talks about setting up access to a set of git repositories
purely via smart http.  The `GIT_HTTP_EXPORT_ALL` variable must be set for
such environments.

However, it is possible to allow both ssh as well as http access, perhaps
using suexec to make the CGI run under the 'git' user [detailed documentation
patches welcome!]  For those environments, this variable is not mandatory.

If you omit that variable, you can decide which repo is accessible via http by
setting `R = daemon` just for those repos.

Please note that there is no way to use "deny" rules for *read* access.  Do
not try:

        repo gitolite-admin
            -   =   daemon

        repo @all
            R   =   daemon

to achieve the (possibly common) need for disallowing http access to the admin
repo.

----

Enjoy!