P2P protocol is finalized
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Joey Hess
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[[!toc ]]
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## motivation
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## introduction
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The [[P2P protocol]] is a custom protocol that git-annex speaks over a ssh
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connection (mostly). This is a design working on supporting the P2P
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protocol over HTTP.
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connection (mostly). This is a translation of that protocol to HTTP.
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Upload of annex objects to git remotes that use http is currently not
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supported by git-annex, and this would be a generally very useful addition.
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## base64 encoding of keys, uuids, and filenames
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For use cases such as OpenNeuro's javascript client, ssh is too difficult
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to support, so they currently use a special remote that talks to a http
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endpoint in order to upload objects. Implementing this would let them
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talk to git-annex over http.
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A git-annex key can contain text in any encoding. So can a filename,
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and it's even possible, though unlikely, that the UUID of a git-annex
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repository might.
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With the [[passthrough_proxy]], this would let clients configure a single
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http remote that accesses a more complicated network of git-annex
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repositories.
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But this protocol requires that UTF-8 be used throughout, except
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where bodies use `Content-Type: application/octet-stream`.
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## integration with git
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So this protocol allows using
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[base64url](https://datatracker.ietf.org/doc/html/rfc4648#section-5)
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encoding for such values. Any key, filename, or UUID wrapped in square
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brackets is a base64url encoded value.
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For example, "[Zm9v]" is the same as "foo".
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A webserver that is configured to serve a git repository either serves the
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files in the repository with dumb http, or uses the git-http-backend CGI
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program for url paths under eg `/git/`.
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A filename like "[foo]" will need to itself be encoded that way: "[W2Zvb10=]"
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To integrate with that, git-annex would need a git-annex-http-backend CGI
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program, that the webserver is configured to run for url paths under
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`/git/.*/annex/`.
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## authentication
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So, for a remote with an url `http://example.com/git/foo`, git-annex would
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use paths under `http://example.com/git/foo/annex/` to run its CGI.
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Some requests need authentication. Which requests do depends on the
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configuration of the HTTP server. When a request needs authentication,
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it will fail with 401 Unauthorized.
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But, the CGI interface is a poor match for the P2P protocol.
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Authentication is done using HTTP basic auth. The realm to use when
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authenticating is "git-annex". The charset is UTF-8.
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A particular problem is that `LOCKCONTENT` would need to be in one CGI
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request, followed by another request to `UNLOCKCONTENT`. Unless
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git-annex-http-backend forked a daemon to keep the content locked, it would
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not be able to retain a file lock across the 2 requests. While the 10
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minute retention lock would paper over that, UNLOCKCONTENT would not be
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able to delete the retention lock, because there is no way to know if
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another LOCKCONTENT was received later. So LOCKCONTENT would always lock
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content for 10 minutes. Which would result in some undesirable behaviors.
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When authentication is successful but does not allow a request to be
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performed, it will fail with 403 Forbidden.
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Another problem is with proxies and clusters. The CGI would need to open
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ssh (or http) connections to the proxied repositories and cluster nodes
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each time it is run. That would add a lot of latency to every request.
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Note that HTTP basic auth is not encrypted so is only secure when used
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over HTTPS.
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And running a git-annex process once per CGI request also makes git-annex's
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own startup speed, which is ok but not great, add latency. And each time
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the CGI needed to change the git-annex branch, it would have to commit on
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shutdown. Lots of time and space optimisations would be prevented by using
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the CGI interface.
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## protocol version
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So, rather than having the CGI program do anything in the repository
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itself, have it pass each request through to a long-running server.
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(This does have the downside that files would get double-copied
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through the CGI, which adds some overhead.)
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A reasonable way to do that would be to have a webserver speaking a
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HTTP version of the git-annex P2P protocol and the CGI just talks to that.
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Requests are versioned. The versions correspond to
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P2P protocol versions. The version is part of the request path,
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eg "v3"
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The CGI program then becomes tiny, and just needs to know the url to
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connect to the git-annex HTTP server.
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If the server does not support a particular protocol version, the
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request will fail with a 404, and the client should fall
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back to an earlier protocol version.
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Alternatively, a remote's configuration could include that url, and
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then we don't need the complication and overhead of the CGI program at all.
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Eg:
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## common request parameters
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git config remote.origin.annex-url http://example.com:8080/
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Every request supports this parameter, and unless documented
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otherwise, it is required to be included.
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So, the rest of this design will focus on implementing that. The CGI
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program can be added later if desired, so avoid users needing to configure
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an additional thing.
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* `clientuuid`
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Note that, one nice benefit of having a separate annex-url is it allows
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having remote.origin.url on eg github, but with an annex-url configured
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that remote can also be used as a git-annex repository.
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The value is the UUID of the git-annex repository of the client.
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## approach 1: websockets
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Any request may also optionally include these parameters:
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The client connects to the server over a websocket. From there on,
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the protocol is encapsulated in websockets.
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* `bypass`
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This seems nice and simple to implement, but not very web native. Anyone
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wanting to talk to this web server would need to understand the P2P
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protocol. Just to upload a file would need to deal with AUTH,
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AUTH-SUCCESS, AUTH-FAILURE, VERSION, PUT, ALREADY-HAVE, PUT-FROM, DATA,
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INVALID, VALID, SUCCESS, and FAILURE messages. Seems like a lot.
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The value is the UUID of a cluster gateway, which the server should avoid
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connecting to when serving a cluster. This is the equivilant of the
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`BYPASS` message in the [[P2P_Protocol]].
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Some requests like `LOCKCONTENT` do need full duplex communication like
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websockets provide. But, it might be more web native to only use websockets
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for that request, and not for everything.
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This parameter can be given multiple times to list several cluster
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gateway UUIDs.
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## approach 2: web-native API
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This parameter is only available for v2 and above.
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Another approach is to define a web-native API with endpoints that
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correspond to each action in the P2P protocol.
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[Internally, git-annex can use these common parameters, plus the protocol
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version, and remote UUID, to create a P2P session. The P2P session is
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driven through the AUTH, VERSION, and BYPASS messages, leaving the session
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ready to service requests.]
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Something like this:
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## requests
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> POST /git-annex/v1/AUTH?clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.0
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< AUTH-SUCCESS ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6
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### GET /git-annex/$uuid/key/$key
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> POST /git-annex/v1/CHECKPRESENT?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925&serveruuid=ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6 HTTP/1.0
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> SUCCESS
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This is a simple, unversioned interface to get the content of a key
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from a repository.
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> POST /git-annex/v1/PUT-FROM?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925&serveruuid=ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6 HTTP/1.0
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< PUT-FROM 0
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It is not part of the P2P protocol per se, but is provided to let
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other clients than git-annex easily download the content of keys from the
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http server.
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> POST /git-annex/v1/PUT?key=SHA1--foo&associatedfile=bar&put-from=0&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925&serveruuid=ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6 HTTP/1.0
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> Content-Type: application/octet-stream
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> Content-Length: 20
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> foo
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> {"valid": true}
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< {"stored": true}
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When the key is not present on the server, it will respond
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with 404 Not Found.
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(In the last example above "foo" is the content, it is followed by a line of json.
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This seems better than needing an entire other request to indicate validitity.)
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### GET /git-annex/$uuid/v3/key/$key
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This needs a more complex spec. But it's easier for others to implement,
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especially since it does not need a session identifier, so the HTTP server can
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be stateless.
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Get the content of a key from the repository with the specified uuid.
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A full draft protocol for this is being developed at [[p2p_protocol_over_http/draft1]].
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Example:
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## HTTP GET
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It should be possible to support a regular HTTP get of a key, with
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no additional parameters, so that annex objects can be served to other clients
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from this web server.
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> GET /git-annex/key/SHA1--foo HTTP/1.0
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> GET /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/key/SHA1--foo&associatedfile=bar&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< X-git-annex-data-length: 3
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< Content-Type: application/octet-stream
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<
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< foo
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Although this would be a special case, not used by git-annex, because the P2P
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protocol's GET has the complication of offsets, and of the server sending
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VALID/INVALID after the content, and of needing to know the client's UUID in
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order to update the location log.
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All parameters are optional, including the common parameters, and these:
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## Problem: CONNECT
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* `associatedfile`
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The CONNECT message allows both sides of the P2P protocol to send DATA
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messages in any order. This seems difficult to encapsulate in HTTP.
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The name of a file in the git repository, for informational purposes
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only.
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Probably this can be not implemented, it's probably not needed for a HTTP
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remote? This is used to tunnel git protocol over the P2P protocol, but for
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a HTTP remote the git repository can be accessed over HTTP as well.
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* `offset`
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## security
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Number of bytes to skip sending from the beginning of the file.
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Should support HTTPS and/or be limited to only HTTPS.
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Request headers are currently ignored, so eg Range requests are
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not supported. (This would be possible to implement, up to a point.)
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Authentication via http basic auth?
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The body of the request is empty.
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The server's response will have a `Content-Type` header of
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`application/octet-stream`.
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The server's response will have a `X-git-annex-data-length`
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header that indicates the number of bytes of content that are expected to
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be sent. Note that there is no Content-Length header.
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The body of the response is the content of the key.
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If the length of the body is different than what the the
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X-git-annex-data-length header indicated, then the data is invalid and
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should not be used. This can happen when eg, the data was being sent from
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an unlocked annexed file, which got modified while it was being sent.
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When the content is not present, the server will respond with
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422 Unprocessable Content.
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### GET /git-annex/$uuid/v2/key/$key
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Identical to v3.
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### GET /git-annex/$uuid/v1/key/$key
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Identical to v3.
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### GET /git-annex/$uuid/v0/key/$key
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Same as v3, except the X-git-annex-data-length header is not used.
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Additional checking client-side will be required to validate the data.
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### POST /git-annex/$uuid/v3/checkpresent
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Checks if a key is currently present on the server.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/checkpresent?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< {"present": true}
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There is one required additional parameter, `key`.
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The body of the request is empty.
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The server responds with a JSON object with a "present" field that is true
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if the key is present, or false if it is not present.
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### POST /git-annex/$uuid/v2/checkpresent
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Identical to v3.
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### POST /git-annex/$uuid/v1/checkpresent
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Identical to v3.
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### POST /git-annex/$uuid/v0/checkpresent
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Identical to v3.
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### POST /git-annex/$uuid/v3/lockcontent
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Locks the content of a key on the server, preventing it from being removed.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/lockcontent?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< {"locked": true, "lockid": "foo"}
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There is one required additional parameter, `key`.
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The server will reply with `{"locked": true}` if it was able
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to lock the key, or `{"locked": false}` if it was not.
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The key will remain locked for 10 minutes. But, usually `keeplocked`
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is used to control the lifetime of the lock, using the "lockid"
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parameter from the server's reply. (See below.)
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### POST /git-annex/$uuid/v2/lockcontent
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Identical to v3.
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### POST /git-annex/$uuid/v1/lockcontent
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Identical to v3.
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### POST /git-annex/$uuid/v0/lockcontent
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Identical to v3.
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### POST /git-annex/$uuid/v3/keeplocked
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Controls the lifetime of a lock on a key that was earlier obtained
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with `lockcontent`.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/keeplocked?lockid=foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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> Connection: Keep-Alive
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> Keep-Alive: timeout=1200
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[some time later]
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> {"unlock": true}
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< {"locked": false}
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There is one required additional parameter, `lockid`.
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This uses long polling. So it's important to use
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Connection and Keep-Alive headers.
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This keeps an active lock from expiring until the client sends
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`{"unlock": true}`, and then it immediately unlocks it.
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The client can send `{"unlock": false}` any number of times first.
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This has no effect, but may be useful to keep the connection alive.
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This must be called within ten minutes of `lockcontent`, otherwise
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the lock will have already expired when this runs. Note that this
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does not indicate if the lock expired, it always returns
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`{"locked": false}`.
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If the connection is closed before the client sends `{"unlock": true},
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or even if the web server gets shut down, the content will remain
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locked for 10 minutes from the time it was first locked.
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Note that the common parameters bypass and clientuuid, while
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accepted, have no effect.
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### POST /git-annex/$uuid/v2/keeplocked
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Identical to v3.
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### POST /git-annex/$uuid/v1/keeplocked
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Identical to v3.
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### POST /git-annex/$uuid/v0/keeplocked
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Identical to v3.
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### POST /git-annex/$uuid/v3/remove
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Remove a key's content from the server.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/remove?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< {"removed": true}
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There is one required additional parameter, `key`.
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The body of the request is empty.
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The server responds with a JSON object with a "removed" field that is true
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if the key was removed (or was not present on the server),
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or false if the key was not able to be removed.
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The JSON object can have an additional field "plusuuids" that is a list of
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UUIDs of other repositories that the content was removed from.
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### POST /git-annex/$uuid/v2/remove
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Identical to v3.
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### POST /git-annex/$uuid/v1/remove
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Same as v3, except the JSON will not include "plusuuids".
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### POST /git-annex/$uuid/v0/remove
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Identical to v1.
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## POST /git-annex/$uuid/v3/remove-before
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Remove a key's content from the server, but only before a specified time.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/remove-before?timestamp=4949292929&key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< {"removed": true}
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This is the same as the `remove` request, but with an additional parameter,
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`timestamp`.
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If the server's monotonic clock is past the specified timestamp, the
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removal will fail and the server will respond with: `{"removed": false}`
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This is used to avoid removing content after a point in
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time where it is no longer locked in other repostitories.
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## POST /git-annex/$uuid/v3/gettimestamp
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Gets the current timestamp from the server.
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Example:
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> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/gettimestamp?clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
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< {"timestamp": 59459392}
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The body of the request is empty.
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The server responds with JSON object with a timestmap field that has the
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current value of its monotonic clock, as a number of seconds.
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Important: If multiple servers are serving this protocol for the same
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repository, they MUST all use the same monotonic clock.
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### POST /git-annex/$uuid/v3/put
|
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Store content on the server.
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Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/put?key=SHA1--foo&associatedfile=bar&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
> Content-Type: application/octet-stream
|
||||
> X-git-annex-data-length: 3
|
||||
>
|
||||
> foo
|
||||
< {"stored": true}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
There are are also these optional parameters:
|
||||
|
||||
* `associatedfile`
|
||||
|
||||
The name of a file in the git repository, for informational purposes
|
||||
only.
|
||||
|
||||
* `offset`
|
||||
|
||||
Number of bytes that have been omitted from the beginning of the file.
|
||||
Usually this will be determined by making a `putoffset` request.
|
||||
|
||||
The `Content-Type` header should be `application/octet-stream`.
|
||||
|
||||
The `X-git-annex-data-length` must be included. It indicates the number
|
||||
of bytes of content that are expected to be sent.
|
||||
Note that there is no need to send a Content-Length header.
|
||||
|
||||
If the length of the body is different than what the the
|
||||
X-git-annex-data-length header indicated, then the data is invalid and
|
||||
should not be used. This can happen when eg, the data was being sent from
|
||||
an unlocked annexed file, which got modified while it was being sent.
|
||||
|
||||
The server responds with a JSON object with a field "stored"
|
||||
that is true if it received the data and stored the content.
|
||||
|
||||
The JSON object can have an additional field "plusuuids" that is a list of
|
||||
UUIDs of other repositories that the content was stored to.
|
||||
|
||||
### POST /git-annex/$uuid/v2/put
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/put
|
||||
|
||||
Same as v3, except the JSON will not include "plusuuids".
|
||||
|
||||
### POST /git-annex/$uuid/v0/put
|
||||
|
||||
Same as v1, except additional checking is done to validate the data.
|
||||
|
||||
### POST /git-annex/$uuid/v3/putoffset
|
||||
|
||||
Asks the server what `offset` can be used in a `put` of a key.
|
||||
|
||||
This should usually be used right before sending a `put` request.
|
||||
The offset may not be valid after some point in time, which could result in
|
||||
the `put` request failing.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/putoffset?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"offset": 10}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server responds with a JSON object with an "offset" field that
|
||||
is the largest allowable offset.
|
||||
|
||||
If the server already has the content of the key, it will respond instead
|
||||
with a JSON object with an "alreadyhave" field that is set to true. This JSON
|
||||
object may also have a field "plusuuids" that lists
|
||||
the UUIDs of other repositories where the content is stored, in addition to
|
||||
the serveruuid.
|
||||
|
||||
[Implementation note: This will be implemented by sending `PUT` and
|
||||
returning the `PUT-FROM` offset. To avoid leaving the P2P protocol stuck
|
||||
part way through a `PUT`, a synthetic empty `DATA` followed by `INVALID`
|
||||
will be used to get the P2P protocol back into a state where it will accept
|
||||
any request.]
|
||||
|
||||
### POST /git-annex/$uuid/v2/putoffset
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/putoffset
|
||||
|
||||
Same as v3, except the JSON will not include "plusuuids".
|
||||
|
||||
## parts of P2P protocol that are not supported over HTTP
|
||||
|
||||
`NOTIFYCHANGE` is not supported, but it would be possible to extend
|
||||
this HTTP protocol to support it.
|
||||
|
||||
`CONNECT` is not supported, and due to the bi-directional message passing
|
||||
nature of it, it cannot easily be done over HTTP (would need websockets).
|
||||
It should not be necessary anyway, because the git repository itself can be
|
||||
accessed over HTTP.
|
||||
|
|
|
|||
|
|
@ -1,423 +0,0 @@
|
|||
[[!toc ]]
|
||||
|
||||
Draft 1 of a complete [[P2P_protocol]] over HTTP.
|
||||
|
||||
## base64 encoding of keys, uuids, and filenames
|
||||
|
||||
A git-annex key can contain text in any encoding. So can a filename,
|
||||
and it's even possible, though unlikely, that the UUID of a git-annex
|
||||
repository might.
|
||||
|
||||
But this protocol requires that UTF-8 be used throughout, except
|
||||
where bodies use `Content-Type: application/octet-stream`.
|
||||
|
||||
So this protocol allows using
|
||||
[base64url](https://datatracker.ietf.org/doc/html/rfc4648#section-5)
|
||||
encoding for such values. Any key, filename, or UUID wrapped in square
|
||||
brackets is a base64url encoded value.
|
||||
For example, "[Zm9v]" is the same as "foo".
|
||||
|
||||
A filename like "[foo]" will need to itself be encoded that way: "[W2Zvb10=]"
|
||||
|
||||
## authentication
|
||||
|
||||
Some requests need authentication. Which requests do depends on the
|
||||
configuration of the HTTP server. When a request needs authentication,
|
||||
it will fail with 401 Unauthorized.
|
||||
|
||||
Authentication is done using HTTP basic auth. The realm to use when
|
||||
authenticating is "git-annex". The charset is UTF-8.
|
||||
|
||||
When authentication is successful but does not allow a request to be
|
||||
performed, it will fail with 403 Forbidden.
|
||||
|
||||
Note that HTTP basic auth is not encrypted so is only secure when used
|
||||
over HTTPS.
|
||||
|
||||
## protocol version
|
||||
|
||||
Each request in the protocol is versioned. The versions correspond
|
||||
to P2P protocol versions.
|
||||
|
||||
If the server does not support a particular protocol version, the
|
||||
request will fail with a 400 Bad Request, and the client should fall
|
||||
back to an earlier protocol version.
|
||||
|
||||
## common request parameters
|
||||
|
||||
Every request supports this parameter, and unless documented
|
||||
otherwise, a request it to be included.
|
||||
|
||||
* `clientuuid`
|
||||
|
||||
The value is the UUID of the git-annex repository of the client.
|
||||
|
||||
Any request may also optionally include these parameters:
|
||||
|
||||
* `bypass`
|
||||
|
||||
The value is the UUID of a cluster gateway, which the server should avoid
|
||||
connecting to when serving a cluster. This is the equivilant of the
|
||||
`BYPASS` message in the [[P2P_Protocol]].
|
||||
|
||||
This parameter can be given multiple times to list several cluster
|
||||
gateway UUIDs.
|
||||
|
||||
This parameter is only available for v2 and above.
|
||||
|
||||
[Internally, git-annex can use these common parameters, plus the protocol
|
||||
version, and remote UUID, to create a P2P session. The P2P session is
|
||||
driven through the AUTH, VERSION, and BYPASS messages, leaving the session
|
||||
ready to service requests.]
|
||||
|
||||
## requests
|
||||
|
||||
### GET /git-annex/$uuid/key/$key
|
||||
|
||||
This is a simple, unversioned interface to get the content of a key
|
||||
from a repository.
|
||||
|
||||
It is not part of the P2P protocol per se, but is provided to let
|
||||
other clients than git-annex easily download the content of keys from the
|
||||
http server.
|
||||
|
||||
When the key is not present on the server, it will respond
|
||||
with 404 Not Found.
|
||||
|
||||
### GET /git-annex/$uuid/v3/key/$key
|
||||
|
||||
Get the content of a key from the repository with the specified uuid.
|
||||
|
||||
Example:
|
||||
|
||||
> GET /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/key/SHA1--foo&associatedfile=bar&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< X-git-annex-data-length: 3
|
||||
< Content-Type: application/octet-stream
|
||||
<
|
||||
< foo
|
||||
|
||||
All parameters are optional, including the common parameters, and these:
|
||||
|
||||
* `associatedfile`
|
||||
|
||||
The name of a file in the git repository, for informational purposes
|
||||
only.
|
||||
|
||||
* `offset`
|
||||
|
||||
Number of bytes to skip sending from the beginning of the file.
|
||||
|
||||
Request headers are currently ignored, so eg Range requests are
|
||||
not supported. (This would be possible to implement, up to a point.)
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server's response will have a `Content-Type` header of
|
||||
`application/octet-stream`.
|
||||
|
||||
The server's response will have a `X-git-annex-data-length`
|
||||
header that indicates the number of bytes of content that are expected to
|
||||
be sent. Note that there is no Content-Length header.
|
||||
|
||||
The body of the response is the content of the key.
|
||||
|
||||
If the length of the body is different than what the the
|
||||
X-git-annex-data-length header indicated, then the data is invalid and
|
||||
should not be used. This can happen when eg, the data was being sent from
|
||||
an unlocked annexed file, which got modified while it was being sent.
|
||||
|
||||
When the content is not present, the server will respond with
|
||||
422 Unprocessable Content.
|
||||
|
||||
### GET /git-annex/$uuid/v2/key/$key
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### GET /git-annex/$uuid/v1/key/$key
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### GET /git-annex/$uuid/v0/key/$key
|
||||
|
||||
Same as v3, except the X-git-annex-data-length header is not used.
|
||||
Additional checking client-side will be required to validate the data.
|
||||
|
||||
### POST /git-annex/$uuid/v3/checkpresent
|
||||
|
||||
Checks if a key is currently present on the server.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/checkpresent?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"present": true}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server responds with a JSON object with a "present" field that is true
|
||||
if the key is present, or false if it is not present.
|
||||
|
||||
### POST /git-annex/$uuid/v2/checkpresent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/checkpresent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v0/checkpresent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v3/lockcontent
|
||||
|
||||
Locks the content of a key on the server, preventing it from being removed.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/lockcontent?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"locked": true, "lockid": "foo"}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
The server will reply with `{"locked": true}` if it was able
|
||||
to lock the key, or `{"locked": false}` if it was not.
|
||||
|
||||
The key will remain locked for 10 minutes. But, usually `keeplocked`
|
||||
is used to control the lifetime of the lock, using the "lockid"
|
||||
parameter from the server's reply. (See below.)
|
||||
|
||||
### POST /git-annex/$uuid/v2/lockcontent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/lockcontent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v0/lockcontent
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v3/keeplocked
|
||||
|
||||
Controls the lifetime of a lock on a key that was earlier obtained
|
||||
with `lockcontent`.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/keeplocked?lockid=foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
> Connection: Keep-Alive
|
||||
> Keep-Alive: timeout=1200
|
||||
[some time later]
|
||||
> {"unlock": true}
|
||||
< {"locked": false}
|
||||
|
||||
There is one required additional parameter, `lockid`.
|
||||
|
||||
This uses long polling. So it's important to use
|
||||
Connection and Keep-Alive headers.
|
||||
|
||||
This keeps an active lock from expiring until the client sends
|
||||
`{"unlock": true}`, and then it immediately unlocks it.
|
||||
|
||||
The client can send `{"unlock": false}` any number of times first.
|
||||
This has no effect, but may be useful to keep the connection alive.
|
||||
|
||||
This must be called within ten minutes of `lockcontent`, otherwise
|
||||
the lock will have already expired when this runs. Note that this
|
||||
does not indicate if the lock expired, it always returns
|
||||
`{"locked": false}`.
|
||||
|
||||
If the connection is closed before the client sends `{"unlock": true},
|
||||
or even if the web server gets shut down, the content will remain
|
||||
locked for 10 minutes from the time it was first locked.
|
||||
|
||||
Note that the common parameters bypass and clientuuid, while
|
||||
accepted, have no effect.
|
||||
|
||||
### POST /git-annex/$uuid/v2/keeplocked
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/keeplocked
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v0/keeplocked
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v3/remove
|
||||
|
||||
Remove a key's content from the server.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/remove?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"removed": true}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server responds with a JSON object with a "removed" field that is true
|
||||
if the key was removed (or was not present on the server),
|
||||
or false if the key was not able to be removed.
|
||||
|
||||
The JSON object can have an additional field "plusuuids" that is a list of
|
||||
UUIDs of other repositories that the content was removed from.
|
||||
|
||||
### POST /git-annex/$uuid/v2/remove
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/remove
|
||||
|
||||
Same as v3, except the JSON will not include "plusuuids".
|
||||
|
||||
### POST /git-annex/$uuid/v0/remove
|
||||
|
||||
Identical to v1.
|
||||
|
||||
## POST /git-annex/$uuid/v3/remove-before
|
||||
|
||||
Remove a key's content from the server, but only before a specified time.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/remove-before?timestamp=4949292929&key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"removed": true}
|
||||
|
||||
This is the same as the `remove` request, but with an additional parameter,
|
||||
`timestamp`.
|
||||
|
||||
If the server's monotonic clock is past the specified timestamp, the
|
||||
removal will fail and the server will respond with: `{"removed": false}`
|
||||
|
||||
This is used to avoid removing content after a point in
|
||||
time where it is no longer locked in other repostitories.
|
||||
|
||||
## POST /git-annex/$uuid/v3/gettimestamp
|
||||
|
||||
Gets the current timestamp from the server.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/gettimestamp?clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"timestamp": 59459392}
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server responds with JSON object with a timestmap field that has the
|
||||
current value of its monotonic clock, as a number of seconds.
|
||||
|
||||
Important: If multiple servers are serving this protocol for the same
|
||||
repository, they MUST all use the same monotonic clock.
|
||||
|
||||
### POST /git-annex/$uuid/v3/put
|
||||
|
||||
Store content on the server.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/put?key=SHA1--foo&associatedfile=bar&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
> Content-Type: application/octet-stream
|
||||
> X-git-annex-data-length: 3
|
||||
>
|
||||
> foo
|
||||
< {"stored": true}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
There are are also these optional parameters:
|
||||
|
||||
* `associatedfile`
|
||||
|
||||
The name of a file in the git repository, for informational purposes
|
||||
only.
|
||||
|
||||
* `offset`
|
||||
|
||||
Number of bytes that have been omitted from the beginning of the file.
|
||||
Usually this will be determined by making a `putoffset` request.
|
||||
|
||||
The `Content-Type` header should be `application/octet-stream`.
|
||||
|
||||
The `X-git-annex-data-length` must be included. It indicates the number
|
||||
of bytes of content that are expected to be sent.
|
||||
Note that there is no need to send a Content-Length header.
|
||||
|
||||
If the length of the body is different than what the the
|
||||
X-git-annex-data-length header indicated, then the data is invalid and
|
||||
should not be used. This can happen when eg, the data was being sent from
|
||||
an unlocked annexed file, which got modified while it was being sent.
|
||||
|
||||
The server responds with a JSON object with a field "stored"
|
||||
that is true if it received the data and stored the content.
|
||||
|
||||
The JSON object can have an additional field "plusuuids" that is a list of
|
||||
UUIDs of other repositories that the content was stored to.
|
||||
|
||||
### POST /git-annex/$uuid/v2/put
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/put
|
||||
|
||||
Same as v3, except the JSON will not include "plusuuids".
|
||||
|
||||
### POST /git-annex/$uuid/v0/put
|
||||
|
||||
Same as v1, except additional checking is done to validate the data.
|
||||
|
||||
### POST /git-annex/$uuid/v3/putoffset
|
||||
|
||||
Asks the server what `offset` can be used in a `put` of a key.
|
||||
|
||||
This should usually be used right before sending a `put` request.
|
||||
The offset may not be valid after some point in time, which could result in
|
||||
the `put` request failing.
|
||||
|
||||
Example:
|
||||
|
||||
> POST /git-annex/ecf6d4ca-07e8-11ef-8990-9b8c1f696bf6/v3/putoffset?key=SHA1--foo&clientuuid=79a5a1f4-07e8-11ef-873d-97f93ca91925 HTTP/1.1
|
||||
< {"offset": 10}
|
||||
|
||||
There is one required additional parameter, `key`.
|
||||
|
||||
The body of the request is empty.
|
||||
|
||||
The server responds with a JSON object with an "offset" field that
|
||||
is the largest allowable offset.
|
||||
|
||||
If the server already has the content of the key, it will respond instead
|
||||
with a JSON object with an "alreadyhave" field that is set to true. This JSON
|
||||
object may also have a field "plusuuids" that lists
|
||||
the UUIDs of other repositories where the content is stored, in addition to
|
||||
the serveruuid.
|
||||
|
||||
[Implementation note: This will be implemented by sending `PUT` and
|
||||
returning the `PUT-FROM` offset. To avoid leaving the P2P protocol stuck
|
||||
part way through a `PUT`, a synthetic empty `DATA` followed by `INVALID`
|
||||
will be used to get the P2P protocol back into a state where it will accept
|
||||
any request.]
|
||||
|
||||
### POST /git-annex/$uuid/v2/putoffset
|
||||
|
||||
Identical to v3.
|
||||
|
||||
### POST /git-annex/$uuid/v1/putoffset
|
||||
|
||||
Same as v3, except the JSON will not include "plusuuids".
|
||||
|
||||
## parts of P2P protocol that are not supported over HTTP
|
||||
|
||||
`NOTIFYCHANGE` is not supported, but it would be possible to extend
|
||||
this HTTP protocol to support it.
|
||||
|
||||
`CONNECT` is not supported, and due to the bi-directional message passing
|
||||
nature of it, it cannot easily be done over HTTP (would need websockets).
|
||||
It should not be necessary anyway, because the git repository itself can be
|
||||
accessed over HTTP.
|
||||
|
|
@ -28,9 +28,9 @@ Planned schedule of work:
|
|||
|
||||
## work notes
|
||||
|
||||
* Test serveLockContent
|
||||
|
||||
* A Locker should expire the lock on its own after 10 minutes initially.
|
||||
* A Locker should expire the lock on its own after 10 minutes,
|
||||
initially. Once keeplocked is called, the expiry should end with the end
|
||||
of that call.
|
||||
|
||||
* Make Remote.Git use http client when remote.name.annex-url is configured.
|
||||
|
||||
|
|
@ -41,10 +41,9 @@ Planned schedule of work:
|
|||
|
||||
## completed items for July's work on p2p protocol over http
|
||||
|
||||
* addressed [[doc/todo/P2P_locking_connection_drop_safety]]
|
||||
* HTTP P2P protocol document [[design/p2p_protocol_over_http]].
|
||||
|
||||
* finalized HTTP P2P protocol draft 1,
|
||||
[[design/p2p_protocol_over_http/draft1]]
|
||||
* addressed [[doc/todo/P2P_locking_connection_drop_safety]]
|
||||
|
||||
* implemented server and client for HTTP P2P protocol
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue