Documentation: document Extra Parameters
Document the server support for Extra Parameters, additional information that the client can send in its first message to the server during a Git client-server interaction. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Tan committed
Oct 16, 2017 at 10:55 UTC
6464679d9620d91b639e2681b9cc6473f3856d09
2 files changed
+44
-7
Documentation/technical/http-protocol.txt
+8
@@ -219,6 +219,10 @@ smart server reply:
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S: 003c2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0\n
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S: 003fa3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}\n
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+The client may send Extra Parameters (see
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+Documentation/technical/pack-protocol.txt) as a colon-separated string
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+in the Git-Protocol HTTP header.
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+
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Dumb Server Response
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^^^^^^^^^^^^^^^^^^^^
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Dumb servers MUST respond with the dumb server reply format.
@@ -269,7 +273,11 @@ the C locale ordering. The stream SHOULD include the default ref
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named `HEAD` as the first ref. The stream MUST include capability
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declarations behind a NUL on the first ref.
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+The returned response contains "version 1" if "version=1" was sent as an
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+Extra Parameter.
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+
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smart_reply = PKT-LINE("# service=$servicename" LF)
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+ *1("version 1")
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ref_list
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"0000"
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ref_list = empty_list / non_empty_list
Documentation/technical/pack-protocol.txt
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-7
@@ -39,6 +39,19 @@ communicates with that invoked process over the SSH connection.
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The file:// transport runs the 'upload-pack' or 'receive-pack'
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process locally and communicates with it over a pipe.
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+Extra Parameters
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+----------------
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+
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+The protocol provides a mechanism in which clients can send additional
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+information in its first message to the server. These are called "Extra
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+Parameters", and are supported by the Git, SSH, and HTTP protocols.
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+
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+Each Extra Parameter takes the form of `<key>=<value>` or `<key>`.
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+
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+Servers that receive any such Extra Parameters MUST ignore all
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+unrecognized keys. Currently, the only Extra Parameter recognized is
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+"version=1".
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+
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Git Transport
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-------------
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@@ -46,18 +59,25 @@ The Git transport starts off by sending the command and repository
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on the wire using the pkt-line format, followed by a NUL byte and a
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hostname parameter, terminated by a NUL byte.
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- 0032git-upload-pack /project.git\0host=myserver.com\0
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+ 0033git-upload-pack /project.git\0host=myserver.com\0
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+
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+The transport may send Extra Parameters by adding an additional NUL
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+byte, and then adding one or more NUL-terminated strings:
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+
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+ 003egit-upload-pack /project.git\0host=myserver.com\0\0version=1\0
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--
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- git-proto-request = request-command SP pathname NUL [ host-parameter NUL ]
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+ git-proto-request = request-command SP pathname NUL
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+ [ host-parameter NUL ] [ NUL extra-parameters ]
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request-command = "git-upload-pack" / "git-receive-pack" /
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"git-upload-archive" ; case sensitive
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pathname = *( %x01-ff ) ; exclude NUL
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host-parameter = "host=" hostname [ ":" port ]
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+ extra-parameters = 1*extra-parameter
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+ extra-parameter = 1*( %x01-ff ) NUL
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--
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-Only host-parameter is allowed in the git-proto-request. Clients
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-MUST NOT attempt to send additional parameters. It is used for the
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+host-parameter is used for the
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git-daemon name based virtual hosting. See --interpolated-path
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option to git daemon, with the %H/%CH format characters.
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@@ -117,6 +137,12 @@ we execute it without the leading '/'.
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v
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ssh user@example.com "git-upload-pack '~alice/project.git'"
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+Depending on the value of the `protocol.version` configuration variable,
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+Git may attempt to send Extra Parameters as a colon-separated string in
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+the GIT_PROTOCOL environment variable. This is done only if
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+the `ssh.variant` configuration variable indicates that the ssh command
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+supports passing environment variables as an argument.
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+
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A few things to remember here:
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- The "command name" is spelled with dash (e.g. git-upload-pack), but
@@ -137,11 +163,13 @@ Reference Discovery
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-------------------
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When the client initially connects the server will immediately respond
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-with a listing of each reference it has (all branches and tags) along
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+with a version number (if "version=1" is sent as an Extra Parameter),
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+and a listing of each reference it has (all branches and tags) along
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with the object name that each reference currently points to.
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- $ echo -e -n "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" |
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+ $ echo -e -n "0044git-upload-pack /schacon/gitbook.git\0host=example.com\0\0version=1\0" |
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nc -v example.com 9418
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+ 000aversion 1
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00887217a7c7e582c46cec22a130adf4b9d7d950fba0 HEAD\0multi_ack thin-pack
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side-band side-band-64k ofs-delta shallow no-progress include-tag
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00441d3fcd5ced445d1abc402225c0b8a1299641f497 refs/heads/integration
@@ -165,7 +193,8 @@ immediately after the ref itself, if presented. A conforming server
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MUST peel the ref if it's an annotated tag.
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----
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- advertised-refs = (no-refs / list-of-refs)
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+ advertised-refs = *1("version 1")
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+ (no-refs / list-of-refs)
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*shallow
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flush-pkt
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