Documentation/git-http-backend.txt

   1 git-http-backend(1)
   2 ===================
   3
   4 NAME
   5 ----
   6 git-http-backend - Server side implementation of Git over HTTP
   7
   8 SYNOPSIS
   9 --------
  10 [verse]
  11 'git http-backend'
  12
  13 DESCRIPTION
  14 -----------
  15 A simple CGI program to serve the contents of a Git repository to Git
  16 clients accessing the repository over http:// and https:// protocols.
  17 The program supports clients fetching using both the smart HTTP protocol
  18 and the backwards-compatible dumb HTTP protocol, as well as clients
  19 pushing using the smart HTTP protocol. It also supports Git's
  20 more-efficient "v2" protocol if properly configured; see the
  21 discussion of `GIT_PROTOCOL` in the ENVIRONMENT section below.
  22
  23 It verifies that the directory has the magic file
  24 "git-daemon-export-ok", and it will refuse to export any Git directory
  25 that hasn't explicitly been marked for export this way (unless the
  26 `GIT_HTTP_EXPORT_ALL` environmental variable is set).
  27
  28 By default, only the `upload-pack` service is enabled, which serves
  29 'git fetch-pack' and 'git ls-remote' clients, which are invoked from
  30 'git fetch', 'git pull', and 'git clone'.  If the client is authenticated,
  31 the `receive-pack` service is enabled, which serves 'git send-pack'
  32 clients, which is invoked from 'git push'.
  33
  34 SERVICES
  35 --------
  36 These services can be enabled/disabled using the per-repository
  37 configuration file:
  38
  39 http.getanyfile::
  40         This serves Git clients older than version 1.6.6 that are unable to use the
  41         upload pack service.  When enabled, clients are able to read
  42         any file within the repository, including objects that are
  43         no longer reachable from a branch but are still present.
  44         It is enabled by default, but a repository can disable it
  45         by setting this configuration item to `false`.
  46
  47 http.uploadpack::
  48         This serves 'git fetch-pack' and 'git ls-remote' clients.
  49         It is enabled by default, but a repository can disable it
  50         by setting this configuration item to `false`.
  51
  52 http.receivepack::
  53         This serves 'git send-pack' clients, allowing push.  It is
  54         disabled by default for anonymous users, and enabled by
  55         default for users authenticated by the web server.  It can be
  56         disabled by setting this item to `false`, or enabled for all
  57         users, including anonymous users, by setting it to `true`.
  58
  59 URL TRANSLATION
  60 ---------------
  61 To determine the location of the repository on disk, 'git http-backend'
  62 concatenates the environment variables PATH_INFO, which is set
  63 automatically by the web server, and GIT_PROJECT_ROOT, which must be set
  64 manually in the web server configuration.  If GIT_PROJECT_ROOT is not
  65 set, 'git http-backend' reads PATH_TRANSLATED, which is also set
  66 automatically by the web server.
  67
  68 EXAMPLES
  69 --------
  70 All of the following examples map `http://$hostname/git/foo/bar.git`
  71 to `/var/www/git/foo/bar.git`.
  72
  73 Apache 2.x::
  74         Ensure mod_cgi, mod_alias, and mod_env are enabled, set
  75         GIT_PROJECT_ROOT (or DocumentRoot) appropriately, and
  76         create a ScriptAlias to the CGI:
  77 +
  78 ----------------------------------------------------------------
  79 SetEnv GIT_PROJECT_ROOT /var/www/git
  80 SetEnv GIT_HTTP_EXPORT_ALL
  81 ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
  82
  83 # This is not strictly necessary using Apache and a modern version of
  84 # git-http-backend, as the webserver will pass along the header in the
  85 # environment as HTTP_GIT_PROTOCOL, and http-backend will copy that into
  86 # GIT_PROTOCOL. But you may need this line (or something similar if you
  87 # are using a different webserver), or if you want to support older Git
  88 # versions that did not do that copying.
  89 #
  90 # Having the webserver set up GIT_PROTOCOL is perfectly fine even with
  91 # modern versions (and will take precedence over HTTP_GIT_PROTOCOL,
  92 # which means it can be used to override the client's request).
  93 SetEnvIf Git-Protocol ".*" GIT_PROTOCOL=$0
  94 ----------------------------------------------------------------
  95 +
  96 To enable anonymous read access but authenticated write access,
  97 require authorization for both the initial ref advertisement (which we
  98 detect as a push via the service parameter in the query string), and the
  99 receive-pack invocation itself:
 100 +
 101 ----------------------------------------------------------------
 102 RewriteCond %{QUERY_STRING} service=git-receive-pack [OR]
 103 RewriteCond %{REQUEST_URI} /git-receive-pack$
 104 RewriteRule ^/git/ - [E=AUTHREQUIRED:yes]
 105
 106 <LocationMatch "^/git/">
 107         Order Deny,Allow
 108         Deny from env=AUTHREQUIRED
 109
 110         AuthType Basic
 111         AuthName "Git Access"
 112         Require group committers
 113         Satisfy Any
 114         ...
 115 </LocationMatch>
 116 ----------------------------------------------------------------
 117 +
 118 If you do not have `mod_rewrite` available to match against the query
 119 string, it is sufficient to just protect `git-receive-pack` itself,
 120 like:
 121 +
 122 ----------------------------------------------------------------
 123 <LocationMatch "^/git/.*/git-receive-pack$">
 124         AuthType Basic
 125         AuthName "Git Access"
 126         Require group committers
 127         ...
 128 </LocationMatch>
 129 ----------------------------------------------------------------
 130 +
 131 In this mode, the server will not request authentication until the
 132 client actually starts the object negotiation phase of the push, rather
 133 than during the initial contact.  For this reason, you must also enable
 134 the `http.receivepack` config option in any repositories that should
 135 accept a push. The default behavior, if `http.receivepack` is not set,
 136 is to reject any pushes by unauthenticated users; the initial request
 137 will therefore report `403 Forbidden` to the client, without even giving
 138 an opportunity for authentication.
 139 +
 140 To require authentication for both reads and writes, use a Location
 141 directive around the repository, or one of its parent directories:
 142 +
 143 ----------------------------------------------------------------
 144 <Location /git/private>
 145         AuthType Basic
 146         AuthName "Private Git Access"
 147         Require group committers
 148         ...
 149 </Location>
 150 ----------------------------------------------------------------
 151 +
 152 To serve gitweb at the same url, use a ScriptAliasMatch to only
 153 those URLs that 'git http-backend' can handle, and forward the
 154 rest to gitweb:
 155 +
 156 ----------------------------------------------------------------
 157 ScriptAliasMatch \
 158         "(?x)^/git/(.*/(HEAD | \
 159                         info/refs | \
 160                         objects/(info/[^/]+ | \
 161                                  [0-9a-f]{2}/[0-9a-f]{38} | \
 162                                  pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
 163                         git-(upload|receive)-pack))$" \
 164         /usr/libexec/git-core/git-http-backend/$1
 165
 166 ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
 167 ----------------------------------------------------------------
 168 +
 169 To serve multiple repositories from different linkgit:gitnamespaces[7] in a
 170 single repository:
 171 +
 172 ----------------------------------------------------------------
 173 SetEnvIf Request_URI "^/git/([^/]*)" GIT_NAMESPACE=$1
 174 ScriptAliasMatch ^/git/[^/]*(.*) /usr/libexec/git-core/git-http-backend/storage.git$1
 175 ----------------------------------------------------------------
 176
 177 Accelerated static Apache 2.x::
 178         Similar to the above, but Apache can be used to return static
 179         files that are stored on disk.  On many systems this may
 180         be more efficient as Apache can ask the kernel to copy the
 181         file contents from the file system directly to the network:
 182 +
 183 ----------------------------------------------------------------
 184 SetEnv GIT_PROJECT_ROOT /var/www/git
 185
 186 AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
 187 AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
 188 ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
 189 ----------------------------------------------------------------
 190 +
 191 This can be combined with the gitweb configuration:
 192 +
 193 ----------------------------------------------------------------
 194 SetEnv GIT_PROJECT_ROOT /var/www/git
 195
 196 AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
 197 AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
 198 ScriptAliasMatch \
 199         "(?x)^/git/(.*/(HEAD | \
 200                         info/refs | \
 201                         objects/info/[^/]+ | \
 202                         git-(upload|receive)-pack))$" \
 203         /usr/libexec/git-core/git-http-backend/$1
 204 ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
 205 ----------------------------------------------------------------
 206
 207 Lighttpd::
 208         Ensure that `mod_cgi`, `mod_alias`, `mod_auth`, `mod_setenv` are
 209         loaded, then set `GIT_PROJECT_ROOT` appropriately and redirect
 210         all requests to the CGI:
 211 +
 212 ----------------------------------------------------------------
 213 alias.url += ( "/git" => "/usr/lib/git-core/git-http-backend" )
 214 $HTTP["url"] =~ "^/git" {
 215         cgi.assign = ("" => "")
 216         setenv.add-environment = (
 217                 "GIT_PROJECT_ROOT" => "/var/www/git",
 218                 "GIT_HTTP_EXPORT_ALL" => ""
 219         )
 220 }
 221 ----------------------------------------------------------------
 222 +
 223 To enable anonymous read access but authenticated write access:
 224 +
 225 ----------------------------------------------------------------
 226 $HTTP["querystring"] =~ "service=git-receive-pack" {
 227         include "git-auth.conf"
 228 }
 229 $HTTP["url"] =~ "^/git/.*/git-receive-pack$" {
 230         include "git-auth.conf"
 231 }
 232 ----------------------------------------------------------------
 233 +
 234 where `git-auth.conf` looks something like:
 235 +
 236 ----------------------------------------------------------------
 237 auth.require = (
 238         "/" => (
 239                 "method" => "basic",
 240                 "realm" => "Git Access",
 241                 "require" => "valid-user"
 242                )
 243 )
 244 # ...and set up auth.backend here
 245 ----------------------------------------------------------------
 246 +
 247 To require authentication for both reads and writes:
 248 +
 249 ----------------------------------------------------------------
 250 $HTTP["url"] =~ "^/git/private" {
 251         include "git-auth.conf"
 252 }
 253 ----------------------------------------------------------------
 254
 255
 256 ENVIRONMENT
 257 -----------
 258 'git http-backend' relies upon the `CGI` environment variables set
 259 by the invoking web server, including:
 260
 261 * PATH_INFO (if GIT_PROJECT_ROOT is set, otherwise PATH_TRANSLATED)
 262 * REMOTE_USER
 263 * REMOTE_ADDR
 264 * CONTENT_TYPE
 265 * QUERY_STRING
 266 * REQUEST_METHOD
 267
 268 The `GIT_HTTP_EXPORT_ALL` environmental variable may be passed to
 269 'git-http-backend' to bypass the check for the "git-daemon-export-ok"
 270 file in each repository before allowing export of that repository.
 271
 272 The `GIT_HTTP_MAX_REQUEST_BUFFER` environment variable (or the
 273 `http.maxRequestBuffer` config variable) may be set to change the
 274 largest ref negotiation request that git will handle during a fetch; any
 275 fetch requiring a larger buffer will not succeed.  This value should not
 276 normally need to be changed, but may be helpful if you are fetching from
 277 a repository with an extremely large number of refs.  The value can be
 278 specified with a unit (e.g., `100M` for 100 megabytes). The default is
 279 10 megabytes.
 280
 281 Clients may probe for optional protocol capabilities (like the v2
 282 protocol) using the `Git-Protocol` HTTP header. In order to support
 283 these, the contents of that header must appear in the `GIT_PROTOCOL`
 284 environment variable. Most webservers will pass this header to the CGI
 285 via the `HTTP_GIT_PROTOCOL` variable, and `git-http-backend` will
 286 automatically copy that to `GIT_PROTOCOL`. However, some webservers may
 287 be more selective about which headers they'll pass, in which case they
 288 need to be configured explicitly (see the mention of `Git-Protocol` in
 289 the Apache config from the earlier EXAMPLES section).
 290
 291 The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and
 292 GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}',
 293 ensuring that any reflogs created by 'git-receive-pack' contain some
 294 identifying information of the remote user who performed the push.
 295
 296 All `CGI` environment variables are available to each of the hooks
 297 invoked by the 'git-receive-pack'.
 298
 299 GIT
 300 ---
 301 Part of the linkgit:git[1] suite