From: Brandon Williams <bmwill@google.com>
To: git@vger.kernel.org
Cc: peff@peff.net, jrnieder@gmail.com, sbeller@google.com,
gitster@pobox.com, jonathantanmy@google.com,
Brandon Williams <bmwill@google.com>
Subject: [RFC 0/7] transitioning to protocol v2
Date: Thu, 24 Aug 2017 15:53:21 -0700 [thread overview]
Message-ID: <20170824225328.8174-1-bmwill@google.com> (raw)
Another version of Git's wire protocol is a topic that has been discussed and
attempted by many in the community over the years. The biggest challenge, as
far as I understand, has been coming up with a transition plan to using the new
server without breaking existing clients and servers. As such this RFC is
really only concerned with solidifying a transition plan. Once it has been
decided how we can transition to a new protocol we can get into decided what
this new protocol would look like (though it would obviously eliminate the ref
advertisement ;).
The best way to preserve functionality with old servers and clients would be to
communicate using the same end point but have the client send a bit of extra
information with its initial request. This extra information would need to be
sent in such a way that old servers ignore it and operate normally (using
protocol v1). The client would then need to be able to look at a server's
response to determine whether the server understands and is speaking v2 or has
ignored the clients request to use a newer protocol and is speaking v1.
Patches 1-5 enable a client to unconditionally send this back-channel
information to a server. This is done by sending a version number after a
second NUL byte in git://, in the envvar GIT_PROTOCOL in file:// and ssh://,
and in an http header in http://, https://. Patches 6-7 teach a client and
upload-pack to send and recognize a request to use protocol v2.
The biggest question I'm trying to answer is if these are reasonable ways with
which to communicate a request to a server to use a newer protocol, without
breaking current servers/clients. As far as I've tested, with patches 1-5
applied I can still communicate with current servers without causing any
problems.
Any comments/discussion is welcome!
Brandon Williams (7):
pkt-line: add packet_write function
pkt-line: add strbuf_packet_read
protocol: tell server that the client understands v2
t: fix ssh tests to cope with using '-o SendEnv=GIT_PROTOCOL'
http: send Git-Protocol-Version header
transport: teach client to recognize v2 server response
upload-pack: ack version 2
builtin/fetch-pack.c | 4 +-
builtin/send-pack.c | 5 +-
connect.c | 196 +++++++++++++++++++++++++++----------------
daemon.c | 28 ++++++-
http.c | 7 ++
pkt-line.c | 27 ++++++
pkt-line.h | 2 +
remote-curl.c | 7 +-
remote.h | 22 ++++-
t/lib-proto-disable.sh | 1 +
t/t5551-http-fetch-smart.sh | 2 +
t/t5601-clone.sh | 10 +--
t/t5602-clone-remote-exec.sh | 4 +-
transport.c | 60 +++++++++++--
upload-pack.c | 11 +++
15 files changed, 286 insertions(+), 100 deletions(-)
--
2.14.1.342.g6490525c54-goog
next reply other threads:[~2017-08-24 22:53 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-24 22:53 Brandon Williams [this message]
2017-08-24 22:53 ` [RFC 1/7] pkt-line: add packet_write function Brandon Williams
2017-08-24 22:53 ` [RFC 2/7] pkt-line: add strbuf_packet_read Brandon Williams
2017-08-24 22:53 ` [RFC 3/7] protocol: tell server that the client understands v2 Brandon Williams
2017-08-25 17:45 ` Junio C Hamano
2017-08-25 18:53 ` Brandon Williams
2017-08-25 18:55 ` Brandon Williams
2017-08-24 22:53 ` [RFC 4/7] t: fix ssh tests to cope with using '-o SendEnv=GIT_PROTOCOL' Brandon Williams
2017-08-24 22:53 ` [RFC 5/7] http: send Git-Protocol-Version header Brandon Williams
2017-08-30 10:55 ` Kevin Daudt
2017-08-24 22:53 ` [RFC 6/7] transport: teach client to recognize v2 server response Brandon Williams
2017-08-24 22:53 ` [RFC 7/7] upload-pack: ack version 2 Brandon Williams
2017-09-01 22:02 ` Bryan Turner
2017-09-01 23:20 ` Brandon Williams
2017-08-25 1:19 ` [RFC 0/7] transitioning to protocol v2 Junio C Hamano
2017-08-25 17:07 ` Stefan Beller
2017-08-25 17:14 ` Junio C Hamano
2017-08-25 17:36 ` Jeff King
2017-08-25 17:29 ` Jeff King
2017-08-25 17:35 ` Jonathan Nieder
2017-08-25 17:41 ` Jeff King
2017-08-25 18:50 ` Brandon Williams
2017-08-29 20:08 ` Jeff Hostetler
2017-08-29 21:10 ` Brandon Williams
2017-08-30 3:06 ` Jeff King
2017-08-30 13:30 ` Jeff Hostetler
2017-08-30 16:54 ` Brandon Williams
2017-08-25 17:48 ` Junio C Hamano
2017-08-30 20:38 ` Bryan Turner
2017-08-30 21:12 ` Brandon Williams
2017-09-01 23:06 ` Bryan Turner
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