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bd4a3d61 JK |
1 | gitremote-helpers(1) |
2 | ==================== | |
6eb996b5 DB |
3 | |
4 | NAME | |
5 | ---- | |
bd4a3d61 | 6 | gitremote-helpers - Helper programs to interact with remote repositories |
6eb996b5 DB |
7 | |
8 | SYNOPSIS | |
9 | -------- | |
7791a1d9 | 10 | [verse] |
b6c8d2d6 | 11 | 'git remote-<transport>' <repository> [<URL>] |
6eb996b5 DB |
12 | |
13 | DESCRIPTION | |
14 | ----------- | |
15 | ||
00b84e9d | 16 | Remote helper programs are normally not used directly by end users, |
2de9b711 TA |
17 | but they are invoked by Git when it needs to interact with remote |
18 | repositories Git does not support natively. A given helper will | |
19 | implement a subset of the capabilities documented here. When Git | |
00b84e9d RR |
20 | needs to interact with a repository using a remote helper, it spawns |
21 | the helper as an independent process, sends commands to the helper's | |
22 | standard input, and expects results from the helper's standard | |
23 | output. Because a remote helper runs as an independent process from | |
2de9b711 TA |
24 | Git, there is no need to re-link Git to add a new helper, nor any |
25 | need to link the helper with the implementation of Git. | |
00b84e9d | 26 | |
2de9b711 | 27 | Every helper must support the "capabilities" command, which Git |
b4fc8d6a JN |
28 | uses to determine what other commands the helper will accept. Those |
29 | other commands can be used to discover and update remote refs, | |
30 | transport objects between the object database and the remote repository, | |
31 | and update the local object store. | |
00b84e9d RR |
32 | |
33 | Git comes with a "curl" family of remote helpers, that handle various | |
34 | transport protocols, such as 'git-remote-http', 'git-remote-https', | |
35 | 'git-remote-ftp' and 'git-remote-ftps'. They implement the capabilities | |
36 | 'fetch', 'option', and 'push'. | |
6eb996b5 | 37 | |
f829a9ea MH |
38 | INVOCATION |
39 | ---------- | |
40 | ||
41 | Remote helper programs are invoked with one or (optionally) two | |
2de9b711 | 42 | arguments. The first argument specifies a remote repository as in Git; |
f829a9ea MH |
43 | it is either the name of a configured remote or a URL. The second |
44 | argument specifies a URL; it is usually of the form | |
45 | '<transport>://<address>', but any arbitrary string is possible. | |
46 | The 'GIT_DIR' environment variable is set up for the remote helper | |
47 | and can be used to determine where to store additional data or from | |
2de9b711 | 48 | which directory to invoke auxiliary Git commands. |
f829a9ea | 49 | |
2de9b711 | 50 | When Git encounters a URL of the form '<transport>://<address>', where |
f829a9ea MH |
51 | '<transport>' is a protocol that it cannot handle natively, it |
52 | automatically invokes 'git remote-<transport>' with the full URL as | |
53 | the second argument. If such a URL is encountered directly on the | |
54 | command line, the first argument is the same as the second, and if it | |
55 | is encountered in a configured remote, the first argument is the name | |
56 | of that remote. | |
57 | ||
2de9b711 | 58 | A URL of the form '<transport>::<address>' explicitly instructs Git to |
f829a9ea MH |
59 | invoke 'git remote-<transport>' with '<address>' as the second |
60 | argument. If such a URL is encountered directly on the command line, | |
61 | the first argument is '<address>', and if it is encountered in a | |
62 | configured remote, the first argument is the name of that remote. | |
63 | ||
64 | Additionally, when a configured remote has 'remote.<name>.vcs' set to | |
2de9b711 | 65 | '<transport>', Git explicitly invokes 'git remote-<transport>' with |
f829a9ea MH |
66 | '<name>' as the first argument. If set, the second argument is |
67 | 'remote.<name>.url'; otherwise, the second argument is omitted. | |
68 | ||
b4fc8d6a JN |
69 | INPUT FORMAT |
70 | ------------ | |
71 | ||
72 | Git sends the remote helper a list of commands on standard input, one | |
73 | per line. The first command is always the 'capabilities' command, in | |
74 | response to which the remote helper must print a list of the | |
75 | capabilities it supports (see below) followed by a blank line. The | |
76 | response to the capabilities command determines what commands Git uses | |
77 | in the remainder of the command stream. | |
78 | ||
79 | The command stream is terminated by a blank line. In some cases | |
80 | (indicated in the documentation of the relevant commands), this blank | |
81 | line is followed by a payload in some other protocol (e.g., the pack | |
82 | protocol), while in others it indicates the end of input. | |
83 | ||
84 | Capabilities | |
85 | ~~~~~~~~~~~~ | |
86 | ||
87 | Each remote helper is expected to support only a subset of commands. | |
2de9b711 | 88 | The operations a helper supports are declared to Git in the response |
b4fc8d6a JN |
89 | to the `capabilities` command (see COMMANDS, below). |
90 | ||
0673bb28 MH |
91 | In the following, we list all defined capabilities and for |
92 | each we list which commands a helper with that capability | |
93 | must provide. | |
b4b106e5 | 94 | |
b4fc8d6a | 95 | Capabilities for Pushing |
0673bb28 | 96 | ^^^^^^^^^^^^^^^^^^^^^^^^ |
b4fc8d6a JN |
97 | 'connect':: |
98 | Can attempt to connect to 'git receive-pack' (for pushing), | |
0673bb28 MH |
99 | 'git upload-pack', etc for communication using |
100 | git's native packfile protocol. This | |
101 | requires a bidirectional, full-duplex connection. | |
b4fc8d6a JN |
102 | + |
103 | Supported commands: 'connect'. | |
104 | ||
105 | 'push':: | |
106 | Can discover remote refs and push local commits and the | |
107 | history leading up to them to new or existing remote refs. | |
108 | + | |
109 | Supported commands: 'list for-push', 'push'. | |
110 | ||
b4b106e5 MH |
111 | 'export':: |
112 | Can discover remote refs and push specified objects from a | |
113 | fast-import stream to remote refs. | |
114 | + | |
115 | Supported commands: 'list for-push', 'export'. | |
116 | ||
2de9b711 | 117 | If a helper advertises 'connect', Git will use it if possible and |
b4b106e5 MH |
118 | fall back to another capability if the helper requests so when |
119 | connecting (see the 'connect' command under COMMANDS). | |
2de9b711 | 120 | When choosing between 'push' and 'export', Git prefers 'push'. |
b4b106e5 MH |
121 | Other frontends may have some other order of preference. |
122 | ||
597b831a MM |
123 | 'no-private-update':: |
124 | When using the 'refspec' capability, git normally updates the | |
125 | private ref on successful push. This update is disabled when | |
126 | the remote-helper declares the capability 'no-private-update'. | |
127 | ||
b4fc8d6a JN |
128 | |
129 | Capabilities for Fetching | |
0673bb28 | 130 | ^^^^^^^^^^^^^^^^^^^^^^^^^ |
b4fc8d6a JN |
131 | 'connect':: |
132 | Can try to connect to 'git upload-pack' (for fetching), | |
133 | 'git receive-pack', etc for communication using the | |
2de9b711 | 134 | Git's native packfile protocol. This |
0673bb28 | 135 | requires a bidirectional, full-duplex connection. |
b4fc8d6a JN |
136 | + |
137 | Supported commands: 'connect'. | |
138 | ||
139 | 'fetch':: | |
140 | Can discover remote refs and transfer objects reachable from | |
141 | them to the local object store. | |
142 | + | |
143 | Supported commands: 'list', 'fetch'. | |
144 | ||
145 | 'import':: | |
146 | Can discover remote refs and output objects reachable from | |
147 | them as a stream in fast-import format. | |
148 | + | |
149 | Supported commands: 'list', 'import'. | |
150 | ||
9ba38048 NTND |
151 | 'check-connectivity':: |
152 | Can guarantee that when a clone is requested, the received | |
153 | pack is self contained and is connected. | |
154 | ||
2de9b711 | 155 | If a helper advertises 'connect', Git will use it if possible and |
b4fc8d6a JN |
156 | fall back to another capability if the helper requests so when |
157 | connecting (see the 'connect' command under COMMANDS). | |
2de9b711 | 158 | When choosing between 'fetch' and 'import', Git prefers 'fetch'. |
b4fc8d6a JN |
159 | Other frontends may have some other order of preference. |
160 | ||
0673bb28 MH |
161 | Miscellaneous capabilities |
162 | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
163 | ||
164 | 'option':: | |
165 | For specifying settings like `verbosity` (how much output to | |
166 | write to stderr) and `depth` (how much history is wanted in the | |
167 | case of a shallow clone) that affect how other commands are | |
168 | carried out. | |
169 | ||
b4fc8d6a | 170 | 'refspec' <refspec>:: |
bb0a5cc9 FC |
171 | For remote helpers that implement 'import' or 'export', this capability |
172 | allows the refs to be constrained to a private namespace, instead of | |
173 | writing to refs/heads or refs/remotes directly. | |
0673bb28 | 174 | It is recommended that all importers providing the 'import' |
21610d82 | 175 | capability use this. It's mandatory for 'export'. |
b4fc8d6a | 176 | + |
0673bb28 | 177 | A helper advertising the capability |
6cf378f0 | 178 | `refspec refs/heads/*:refs/svn/origin/branches/*` |
0673bb28 MH |
179 | is saying that, when it is asked to `import refs/heads/topic`, the |
180 | stream it outputs will update the `refs/svn/origin/branches/topic` | |
181 | ref. | |
b4fc8d6a JN |
182 | + |
183 | This capability can be advertised multiple times. The first | |
184 | applicable refspec takes precedence. The left-hand of refspecs | |
185 | advertised with this capability must cover all refs reported by | |
7a43c554 FC |
186 | the list command. If no 'refspec' capability is advertised, |
187 | there is an implied `refspec *:*`. | |
3f36eb43 MM |
188 | + |
189 | When writing remote-helpers for decentralized version control | |
190 | systems, it is advised to keep a local copy of the repository to | |
191 | interact with, and to let the private namespace refs point to this | |
192 | local repository, while the refs/remotes namespace is used to track | |
193 | the remote repository. | |
b4fc8d6a | 194 | |
0673bb28 MH |
195 | 'bidi-import':: |
196 | This modifies the 'import' capability. | |
197 | The fast-import commands 'cat-blob' and 'ls' can be used by remote-helpers | |
198 | to retrieve information about blobs and trees that already exist in | |
199 | fast-import's memory. This requires a channel from fast-import to the | |
200 | remote-helper. | |
2de9b711 | 201 | If it is advertised in addition to "import", Git establishes a pipe from |
0673bb28 | 202 | fast-import to the remote-helper's stdin. |
2de9b711 TA |
203 | It follows that Git and fast-import are both connected to the |
204 | remote-helper's stdin. Because Git can send multiple commands to | |
0673bb28 MH |
205 | the remote-helper it is required that helpers that use 'bidi-import' |
206 | buffer all 'import' commands of a batch before sending data to fast-import. | |
207 | This is to prevent mixing commands and fast-import responses on the | |
208 | helper's stdin. | |
209 | ||
210 | 'export-marks' <file>:: | |
2de9b711 | 211 | This modifies the 'export' capability, instructing Git to dump the |
0673bb28 MH |
212 | internal marks table to <file> when complete. For details, |
213 | read up on '--export-marks=<file>' in linkgit:git-fast-export[1]. | |
214 | ||
215 | 'import-marks' <file>:: | |
2de9b711 | 216 | This modifies the 'export' capability, instructing Git to load the |
0673bb28 MH |
217 | marks specified in <file> before processing any input. For details, |
218 | read up on '--import-marks=<file>' in linkgit:git-fast-export[1]. | |
219 | ||
0d957a4d JK |
220 | 'signed-tags':: |
221 | This modifies the 'export' capability, instructing Git to pass | |
222 | '--signed-tags=verbatim' to linkgit:git-fast-export[1]. In the | |
223 | absence of this capability, Git will use '--signed-tags=warn-strip'. | |
0673bb28 MH |
224 | |
225 | ||
226 | ||
6eb996b5 DB |
227 | COMMANDS |
228 | -------- | |
229 | ||
230 | Commands are given by the caller on the helper's standard input, one per line. | |
231 | ||
232 | 'capabilities':: | |
233 | Lists the capabilities of the helper, one per line, ending | |
d43427d3 | 234 | with a blank line. Each capability may be preceded with '*', |
2de9b711 | 235 | which marks them mandatory for Git versions using the remote |
b20c457a MH |
236 | helper to understand. Any unknown mandatory capability is a |
237 | fatal error. | |
754cb1ae MH |
238 | + |
239 | Support for this command is mandatory. | |
6eb996b5 DB |
240 | |
241 | 'list':: | |
242 | Lists the refs, one per line, in the format "<value> <name> | |
243 | [<attr> ...]". The value may be a hex sha1 hash, "@<dest>" for | |
244 | a symref, or "?" to indicate that the helper could not get the | |
245 | value of the ref. A space-separated list of attributes follows | |
d43427d3 RR |
246 | the name; unrecognized attributes are ignored. The list ends |
247 | with a blank line. | |
ae4efe19 | 248 | + |
9ec8bcda MH |
249 | See REF LIST ATTRIBUTES for a list of currently defined attributes. |
250 | + | |
754cb1ae MH |
251 | Supported if the helper has the "fetch" or "import" capability. |
252 | ||
253 | 'list for-push':: | |
254 | Similar to 'list', except that it is used if and only if | |
255 | the caller wants to the resulting ref list to prepare | |
256 | push commands. | |
257 | A helper supporting both push and fetch can use this | |
258 | to distinguish for which operation the output of 'list' | |
259 | is going to be used, possibly reducing the amount | |
260 | of work that needs to be performed. | |
261 | + | |
262 | Supported if the helper has the "push" or "export" capability. | |
6eb996b5 | 263 | |
ef08ef9e | 264 | 'option' <name> <value>:: |
d43427d3 | 265 | Sets the transport helper option <name> to <value>. Outputs a |
ef08ef9e SP |
266 | single line containing one of 'ok' (option successfully set), |
267 | 'unsupported' (option not recognized) or 'error <msg>' | |
d43427d3 | 268 | (option <name> is supported but <value> is not valid |
ef08ef9e | 269 | for it). Options should be set before other commands, |
d43427d3 | 270 | and may influence the behavior of those commands. |
ef08ef9e | 271 | + |
9ec8bcda MH |
272 | See OPTIONS for a list of currently defined options. |
273 | + | |
ef08ef9e | 274 | Supported if the helper has the "option" capability. |
6eb996b5 DB |
275 | |
276 | 'fetch' <sha1> <name>:: | |
292ce46b SP |
277 | Fetches the given object, writing the necessary objects |
278 | to the database. Fetch commands are sent in a batch, one | |
d43427d3 | 279 | per line, terminated with a blank line. |
292ce46b SP |
280 | Outputs a single blank line when all fetch commands in the |
281 | same batch are complete. Only objects which were reported | |
9ec8bcda | 282 | in the output of 'list' with a sha1 may be fetched this way. |
292ce46b SP |
283 | + |
284 | Optionally may output a 'lock <file>' line indicating a file under | |
285 | GIT_DIR/objects/pack which is keeping a pack until refs can be | |
286 | suitably updated. | |
6eb996b5 | 287 | + |
9ba38048 NTND |
288 | If option 'check-connectivity' is requested, the helper must output |
289 | 'connectivity-ok' if the clone is self-contained and connected. | |
290 | + | |
6eb996b5 DB |
291 | Supported if the helper has the "fetch" capability. |
292 | ||
ae4efe19 | 293 | 'push' +<src>:<dst>:: |
d43427d3 | 294 | Pushes the given local <src> commit or branch to the |
ae4efe19 | 295 | remote branch described by <dst>. A batch sequence of |
960e3114 MM |
296 | one or more 'push' commands is terminated with a blank line |
297 | (if there is only one reference to push, a single 'push' command | |
298 | is followed by a blank line). For example, the following would | |
299 | be two batches of 'push', the first asking the remote-helper | |
300 | to push the local ref 'master' to the remote ref 'master' and | |
301 | the local 'HEAD' to the remote 'branch', and the second | |
302 | asking to push ref 'foo' to ref 'bar' (forced update requested | |
303 | by the '+'). | |
304 | + | |
305 | ------------ | |
306 | push refs/heads/master:refs/heads/master | |
307 | push HEAD:refs/heads/branch | |
308 | \n | |
309 | push +refs/heads/foo:refs/heads/bar | |
310 | \n | |
311 | ------------ | |
ae4efe19 SP |
312 | + |
313 | Zero or more protocol options may be entered after the last 'push' | |
314 | command, before the batch's terminating blank line. | |
315 | + | |
316 | When the push is complete, outputs one or more 'ok <dst>' or | |
317 | 'error <dst> <why>?' lines to indicate success or failure of | |
318 | each pushed ref. The status report output is terminated by | |
319 | a blank line. The option field <why> may be quoted in a C | |
320 | style string if it contains an LF. | |
321 | + | |
322 | Supported if the helper has the "push" capability. | |
323 | ||
e65e91ed DB |
324 | 'import' <name>:: |
325 | Produces a fast-import stream which imports the current value | |
326 | of the named ref. It may additionally import other refs as | |
72ff8943 DB |
327 | needed to construct the history efficiently. The script writes |
328 | to a helper-specific private namespace. The value of the named | |
329 | ref should be written to a location in this namespace derived | |
330 | by applying the refspecs from the "refspec" capability to the | |
331 | name of the ref. | |
e65e91ed | 332 | + |
d43427d3 RR |
333 | Especially useful for interoperability with a foreign versioning |
334 | system. | |
335 | + | |
960e3114 MM |
336 | Just like 'push', a batch sequence of one or more 'import' is |
337 | terminated with a blank line. For each batch of 'import', the remote | |
338 | helper should produce a fast-import stream terminated by a 'done' | |
339 | command. | |
340 | + | |
271bfd67 FA |
341 | Note that if the 'bidi-import' capability is used the complete batch |
342 | sequence has to be buffered before starting to send data to fast-import | |
343 | to prevent mixing of commands and fast-import responses on the helper's | |
344 | stdin. | |
345 | + | |
754cb1ae | 346 | Supported if the helper has the "import" capability. |
e65e91ed | 347 | |
b4b106e5 MH |
348 | 'export':: |
349 | Instructs the remote helper that any subsequent input is | |
350 | part of a fast-import stream (generated by 'git fast-export') | |
351 | containing objects which should be pushed to the remote. | |
352 | + | |
353 | Especially useful for interoperability with a foreign versioning | |
354 | system. | |
355 | + | |
356 | The 'export-marks' and 'import-marks' capabilities, if specified, | |
357 | affect this command in so far as they are passed on to 'git | |
358 | fast-export', which then will load/store a table of marks for | |
359 | local objects. This can be used to implement for incremental | |
360 | operations. | |
361 | + | |
754cb1ae | 362 | Supported if the helper has the "export" capability. |
b4b106e5 | 363 | |
fa8c097c IL |
364 | 'connect' <service>:: |
365 | Connects to given service. Standard input and standard output | |
366 | of helper are connected to specified service (git prefix is | |
367 | included in service name so e.g. fetching uses 'git-upload-pack' | |
368 | as service) on remote side. Valid replies to this command are | |
369 | empty line (connection established), 'fallback' (no smart | |
370 | transport support, fall back to dumb transports) and just | |
371 | exiting with error message printed (can't connect, don't | |
372 | bother trying to fall back). After line feed terminating the | |
373 | positive (empty) response, the output of service starts. After | |
374 | the connection ends, the remote helper exits. | |
375 | + | |
376 | Supported if the helper has the "connect" capability. | |
377 | ||
6eb996b5 DB |
378 | If a fatal error occurs, the program writes the error message to |
379 | stderr and exits. The caller should expect that a suitable error | |
380 | message has been printed if the child closes the connection without | |
381 | completing a valid response for the current command. | |
382 | ||
383 | Additional commands may be supported, as may be determined from | |
384 | capabilities reported by the helper. | |
385 | ||
6eb996b5 DB |
386 | REF LIST ATTRIBUTES |
387 | ------------------- | |
388 | ||
9ec8bcda MH |
389 | The 'list' command produces a list of refs in which each ref |
390 | may be followed by a list of attributes. The following ref list | |
391 | attributes are defined. | |
6eb996b5 | 392 | |
f8ec9167 DB |
393 | 'unchanged':: |
394 | This ref is unchanged since the last import or fetch, although | |
395 | the helper cannot necessarily determine what value that produced. | |
6eb996b5 | 396 | |
ef08ef9e SP |
397 | OPTIONS |
398 | ------- | |
9ec8bcda MH |
399 | |
400 | The following options are defined and (under suitable circumstances) | |
2de9b711 | 401 | set by Git if the remote helper has the 'option' capability. |
9ec8bcda | 402 | |
3b0d2405 | 403 | 'option verbosity' <n>:: |
d43427d3 | 404 | Changes the verbosity of messages displayed by the helper. |
3b0d2405 | 405 | A value of 0 for <n> means that processes operate |
d43427d3 RR |
406 | quietly, and the helper produces only error output. |
407 | 1 is the default level of verbosity, and higher values | |
3b0d2405 | 408 | of <n> correspond to the number of -v flags passed on the |
ef08ef9e SP |
409 | command line. |
410 | ||
411 | 'option progress' \{'true'|'false'\}:: | |
d43427d3 | 412 | Enables (or disables) progress messages displayed by the |
ef08ef9e SP |
413 | transport helper during a command. |
414 | ||
415 | 'option depth' <depth>:: | |
d43427d3 | 416 | Deepens the history of a shallow repository. |
ef08ef9e SP |
417 | |
418 | 'option followtags' \{'true'|'false'\}:: | |
419 | If enabled the helper should automatically fetch annotated | |
420 | tag objects if the object the tag points at was transferred | |
421 | during the fetch command. If the tag is not fetched by | |
422 | the helper a second fetch command will usually be sent to | |
423 | ask for the tag specifically. Some helpers may be able to | |
424 | use this option to avoid a second network connection. | |
425 | ||
ae4efe19 SP |
426 | 'option dry-run' \{'true'|'false'\}: |
427 | If true, pretend the operation completed successfully, | |
428 | but don't actually change any repository data. For most | |
429 | helpers this only applies to the 'push', if supported. | |
430 | ||
fa8c097c | 431 | 'option servpath <c-style-quoted-path>':: |
d43427d3 RR |
432 | Sets service path (--upload-pack, --receive-pack etc.) for |
433 | next connect. Remote helper may support this option, but | |
434 | must not rely on this option being set before | |
fa8c097c IL |
435 | connect request occurs. |
436 | ||
9ba38048 NTND |
437 | 'option check-connectivity' \{'true'|'false'\}:: |
438 | Request the helper to check connectivity of a clone. | |
439 | ||
510fa6f5 FC |
440 | 'option force' \{'true'|'false'\}:: |
441 | Request the helper to perform a force update. Defaults to | |
442 | 'false'. | |
443 | ||
16094885 NTND |
444 | 'option cloning \{'true'|'false'\}:: |
445 | Notify the helper this is a clone request (i.e. the current | |
446 | repository is guaranteed empty). | |
447 | ||
448 | 'option update-shallow \{'true'|'false'\}:: | |
449 | Allow to extend .git/shallow if the new refs require it. | |
450 | ||
b6c8d2d6 RR |
451 | SEE ALSO |
452 | -------- | |
453 | linkgit:git-remote[1] | |
454 | ||
9609dc9d MM |
455 | linkgit:git-remote-testgit[1] |
456 | ||
6eb996b5 DB |
457 | GIT |
458 | --- | |
459 | Part of the linkgit:git[1] suite |