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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | SERVICES | URL TRANSLATION | EXAMPLES | ENVIRONMENT | GIT | COLOPHON |
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GIT-HTTP-BACKEND(1) Git Manual GIT-HTTP-BACKEND(1)
git-http-backend - Server side implementation of Git over HTTP
git http-backend
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 also supports Git’s more-efficient "v2" protocol if
properly configured; see the discussion of GIT_PROTOCOL in the
ENVIRONMENT section below.
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 environment 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.
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 value 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 value 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.
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.
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/
# This is not strictly necessary using Apache and a modern version of
# git-http-backend, as the webserver will pass along the header in the
# environment as HTTP_GIT_PROTOCOL, and http-backend will copy that into
# GIT_PROTOCOL. But you may need this line (or something similar if you
# are using a different webserver), or if you want to support older Git
# versions that did not do that copying.
#
# Having the webserver set up GIT_PROTOCOL is perfectly fine even with
# modern versions (and will take precedence over HTTP_GIT_PROTOCOL,
# which means it can be used to override the client's request).
SetEnvIf Git-Protocol ".*" GIT_PROTOCOL=$0
To enable anonymous read access but authenticated write
access, require authorization for both the initial ref
advertisement (which we detect as a push via the service
parameter in the query string), and the receive-pack
invocation itself:
RewriteCond %{QUERY_STRING} service=git-receive-pack [OR]
RewriteCond %{REQUEST_URI} /git-receive-pack$
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"
}
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 environment 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 option) 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.
Clients may probe for optional protocol capabilities (like the v2
protocol) using the Git-Protocol HTTP header. In order to support
these, the contents of that header must appear in the
GIT_PROTOCOL environment variable. Most webservers will pass this
header to the CGI via the HTTP_GIT_PROTOCOL variable, and
git-http-backend will automatically copy that to GIT_PROTOCOL.
However, some webservers may be more selective about which
headers they’ll pass, in which case they need to be configured
explicitly (see the mention of Git-Protocol in the Apache config
from the earlier EXAMPLES section).
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.
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2024-06-14. (At that time,
the date of the most recent commit that was found in the
repository was 2024-06-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Git 2.45.2.492.gd63586 2024-06-12 GIT-HTTP-BACKEND(1)
Pages that refer to this page: git(1), git-receive-pack(1), git-upload-pack(1), giteveryday(7), gitnamespaces(7)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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