git-http-backend(1)
NAME
git-http-backend - Server side implementation of Git over HTTP
SYNOPSIS
git http-backend
DESCRIPTION
A simple CGI program to serve the contents of a Git repository to Git clients accessing the repository over http:// and https:// protocols. The program supports clients fetching using both the smart HTTP protocol and the backwards-compatible dumb HTTP protocol, as well as clients pushing using the smart HTTP protocol. It verifies that the directory has the magic file "git-daemon-export-ok", and it will refuse to export any Git directory that hasn't explicitly been marked for export this way (unless the GIT_HTTP_EXPORT_ALL environmental variable is set). By default, only the upload-pack service is enabled, which serves git fetch-pack and git ls-remote clients, which are invoked from git fetch, git pull, and git clone. If the client is authenticated, the receive-pack service is enabled, which serves git send-pack clients, which is invoked from git push.
SERVICES
These services can be enabled/disabled using the per-repository
configuration file:
http.getanyfile
This serves Git clients older than version 1.6.6 that are unable to
use the upload pack service. When enabled, clients are able to read
any file within the repository, including objects that are no
longer reachable from a branch but are still present. It is enabled
by default, but a repository can disable it by setting this
configuration item to false.
http.uploadpack
This serves git fetch-pack and git ls-remote clients. It is enabled
by default, but a repository can disable it by setting this
configuration item to false.
http.receivepack
This serves git send-pack clients, allowing push. It is disabled by
default for anonymous users, and enabled by default for users
authenticated by the web server. It can be disabled by setting this
item to false, or enabled for all users, including anonymous users,
by setting it to true.
URL TRANSLATION
To determine the location of the repository on disk, git http-backend concatenates the environment variables PATH_INFO, which is set automatically by the web server, and GIT_PROJECT_ROOT, which must be set manually in the web server configuration. If GIT_PROJECT_ROOT is not set, git http-backend reads PATH_TRANSLATED, which is also set automatically by the web server.
EXAMPLES
All of the following examples map http://$hostname/git/foo/bar.git to
/var/www/git/foo/bar.git.
Apache 2.x
Ensure mod_cgi, mod_alias, and mod_env are enabled, set
GIT_PROJECT_ROOT (or DocumentRoot) appropriately, and create a
ScriptAlias to the CGI:
SetEnv GIT_PROJECT_ROOT /var/www/git
SetEnv GIT_HTTP_EXPORT_ALL
ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
To enable anonymous read access but authenticated write access,
require authorization for both the initial ref advertisement (which
we detect as a push via the service parameter in the query string),
and the receive-pack invocation itself:
RewriteCond %{QUERY_STRING} service=git-receive-pack [OR]
RewriteCond %{REQUEST_URI} /git-receive-pack$
RewriteRule ^/git/ - [E=AUTHREQUIRED:yes]
<LocationMatch "^/git/">
Order Deny,Allow
Deny from env=AUTHREQUIRED
AuthType Basic
AuthName "Git Access"
Require group committers
Satisfy Any
...
</LocationMatch>
If you do not have mod_rewrite available to match against the query
string, it is sufficient to just protect git-receive-pack itself,
like:
<LocationMatch "^/git/.*/git-receive-pack$">
AuthType Basic
AuthName "Git Access"
Require group committers
...
</LocationMatch>
In this mode, the server will not request authentication until the
client actually starts the object negotiation phase of the push,
rather than during the initial contact. For this reason, you must
also enable the http.receivepack config option in any repositories
that should accept a push. The default behavior, if
http.receivepack is not set, is to reject any pushes by
unauthenticated users; the initial request will therefore report
403 Forbidden to the client, without even giving an opportunity for
authentication.
To require authentication for both reads and writes, use a Location
directive around the repository, or one of its parent directories:
<Location /git/private>
AuthType Basic
AuthName "Private Git Access"
Require group committers
...
</Location>
To serve gitweb at the same url, use a ScriptAliasMatch to only
those URLs that git http-backend can handle, and forward the rest
to gitweb:
ScriptAliasMatch \
"(?x)^/git/(.*/(HEAD | \
info/refs | \
objects/(info/[^/]+ | \
[0-9a-f]{2}/[0-9a-f]{38} | \
pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
git-(upload|receive)-pack))$" \
/usr/libexec/git-core/git-http-backend/$1
ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
To serve multiple repositories from different gitnamespaces(7) in a
single repository:
SetEnvIf Request_URI "^/git/([^/]*)" GIT_NAMESPACE=$1
ScriptAliasMatch ^/git/[^/]*(.*) /usr/libexec/git-core/git-http-backend/storage.git$1
Accelerated static Apache 2.x
Similar to the above, but Apache can be used to return static files
that are stored on disk. On many systems this may be more efficient
as Apache can ask the kernel to copy the file contents from the
file system directly to the network:
SetEnv GIT_PROJECT_ROOT /var/www/git
AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$ /var/www/git/$1
AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
This can be combined with the gitweb configuration:
SetEnv GIT_PROJECT_ROOT /var/www/git
AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$ /var/www/git/$1
AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
ScriptAliasMatch \
"(?x)^/git/(.*/(HEAD | \
info/refs | \
objects/info/[^/]+ | \
git-(upload|receive)-pack))$" \
/usr/libexec/git-core/git-http-backend/$1
ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
Lighttpd
Ensure that mod_cgi, mod_alias, mod_auth, mod_setenv are loaded,
then set GIT_PROJECT_ROOT appropriately and redirect all requests
to the CGI:
alias.url += ( "/git" => "/usr/lib/git-core/git-http-backend" )
$HTTP["url"] =~ "^/git" {
cgi.assign = ("" => "")
setenv.add-environment = (
"GIT_PROJECT_ROOT" => "/var/www/git",
"GIT_HTTP_EXPORT_ALL" => ""
)
}
To enable anonymous read access but authenticated write access:
$HTTP["querystring"] =~ "service=git-receive-pack" {
include "git-auth.conf"
}
$HTTP["url"] =~ "^/git/.*/git-receive-pack$" {
include "git-auth.conf"
}
where git-auth.conf looks something like:
auth.require = (
"/" => (
"method" => "basic",
"realm" => "Git Access",
"require" => "valid-user"
)
)
# ...and set up auth.backend here
To require authentication for both reads and writes:
$HTTP["url"] =~ "^/git/private" {
include "git-auth.conf"
}
ENVIRONMENT
git http-backend relies upon the CGI environment variables set by the
invoking web server, including:
* PATH_INFO (if GIT_PROJECT_ROOT is set, otherwise PATH_TRANSLATED)
* REMOTE_USER
* REMOTE_ADDR
* CONTENT_TYPE
* QUERY_STRING
* REQUEST_METHOD
The GIT_HTTP_EXPORT_ALL environmental variable may be passed to
git-http-backend to bypass the check for the "git-daemon-export-ok"
file in each repository before allowing export of that repository.
The GIT_HTTP_MAX_REQUEST_BUFFER environment variable (or the
http.maxRequestBuffer config variable) may be set to change the largest
ref negotiation request that git will handle during a fetch; any fetch
requiring a larger buffer will not succeed. This value should not
normally need to be changed, but may be helpful if you are fetching
from a repository with an extremely large number of refs. The value can
be specified with a unit (e.g., 100M for 100 megabytes). The default is
10 megabytes.
The backend process sets GIT_COMMITTER_NAME to $REMOTE_USER and
GIT_COMMITTER_EMAIL to ${REMOTE_USER}@http.${REMOTE_ADDR}, ensuring
that any reflogs created by git-receive-pack contain some identifying
information of the remote user who performed the push.
All CGI environment variables are available to each of the hooks
invoked by the git-receive-pack.
GIT
Part of the git(1) suite
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
