git-http-backend manpage

Search topic Section


       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 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.

       These services can be enabled/disabled using the per-repository
       configuration file:

	   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.

	   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.

	   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

       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
	       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

	   If you do not have mod_rewrite available to match against the query
	   string, it is sufficient to just protect git-receive-pack itself,

	       <LocationMatch "^/git/.*/git-receive-pack$">
		       AuthType Basic
		       AuthName "Git Access"
		       Require group committers

	   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

	   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

	   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))$" \

	       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/$1
	       ScriptAliasMatch \
		       "(?x)^/git/(.*/(HEAD | \
				       info/refs | \
				       objects/info/[^/]+ | \
				       git-(upload|receive)-pack))$" \
	       ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/

	   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:

       o   PATH_INFO (if GIT_PROJECT_ROOT is set, otherwise PATH_TRANSLATED)

       o   REMOTE_USER

       o   REMOTE_ADDR

       o   CONTENT_TYPE

       o   QUERY_STRING


       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.

       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

Git 2.38.4			  05/16/2024		   GIT-HTTP-BACKEND(1)