wireproto: define and implement HTTP handshake to upgrade protocol
When clients connect to repositories over HTTP, they issue a request
to the well-known URL "?cmd=capabilities" to fetch the repository
capabilities. This is the handshake portion of the HTTP protocol.
This commit defines a mechanism to use that HTTP request to return
information about modern server features.
If a client sends an X-HgUpgrade-* header containing a list of
client-supported API names, the server responds with a response
containing information about available services. This includes
the normal capabilities string. So if the server doesn't support
any newer services, the client can easily fall back.
By advertising supported services from clients, server operators
can see and log what client support exists in the wild. This will
also help with debugging.
The response contains the base path to API services. We know there
are potential issues with the <repo>/api/ URL space conflicting with
hgwebdir and subrepos. By making the API URL dynamic from the
perspective of the client, the URL for APIs is not subject to backwards
compatibility concerns - at least as long as a ?cmd=capabilities request
is made.
We've also defined the ``cbor`` client capability for the X-HgProto-*
header. This MUST be sent in order to get the modern response from
"?cmd=capabilities". During implementation, I initially always sent
an application/mercurial-cbor response. However, the handshake
mechanism will be more future compatible if the client is in charge
of which formats to request. We already perform content negotiation
from X-HgProto-*, so keying off this for the capabilities response
feels appropriate.
In addition, I initially used application/cbor. However, it is
conceivable that a non-Mercurial server could serve application/cbor.
To rule out this possibility, I've invented a new media type that
is Mercurial specific and can't be confused for generic CBOR.
Differential Revision: https://phab.mercurial-scm.org/D3242
#require killdaemons no-reposimplestore
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[255]
$ test -d copy
[1]
This server doesn't do range requests so it's basically only good for
one pull
$ $PYTHON "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid \
> --logfile server.log
$ cat dumb.pid >> $DAEMON_PIDS
$ hg init remote
$ cd remote
$ echo foo > bar
$ echo c2 > '.dotfile with spaces'
$ hg add
adding .dotfile with spaces
adding bar
$ hg commit -m"test"
$ hg tip
changeset: 0:02770d679fb8
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: test
$ cd ..
$ hg clone static-http://localhost:$HGPORT/remote local
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 2 changes to 2 files
new changesets 02770d679fb8
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 1 changesets, 2 total revisions
$ cat bar
foo
$ cd ../remote
$ echo baz > quux
$ hg commit -A -mtest2
adding quux
check for HTTP opener failures when cachefile does not exist
$ rm .hg/cache/*
$ cd ../local
$ cat >> .hg/hgrc <<EOF
> [hooks]
> changegroup = sh -c "printenv.py changegroup"
> EOF
$ hg pull
pulling from static-http://localhost:$HGPORT/remote
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 4ac2e3648604
changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_NODE_LAST=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=http://localhost:$HGPORT/remote
(run 'hg update' to get a working copy)
trying to push
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo more foo >> bar
$ hg commit -m"test"
$ hg push
pushing to static-http://localhost:$HGPORT/remote
abort: destination does not support push
[255]
trying clone -r
$ cd ..
$ hg clone -r doesnotexist static-http://localhost:$HGPORT/remote local0
abort: unknown revision 'doesnotexist'!
[255]
$ hg clone -r 0 static-http://localhost:$HGPORT/remote local0
adding changesets
adding manifests
adding file changes
added 1 changesets with 2 changes to 2 files
new changesets 02770d679fb8
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
test with "/" URI (issue747) and subrepo
$ hg init
$ hg init sub
$ touch sub/test
$ hg -R sub commit -A -m "test"
adding test
$ hg -R sub tag not-empty
$ echo sub=sub > .hgsub
$ echo a > a
$ hg add a .hgsub
$ hg -q ci -ma
$ hg clone static-http://localhost:$HGPORT/ local2
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 3 changes to 3 files
new changesets a9ebfbe8e587
updating to branch default
cloning subrepo sub from static-http://localhost:$HGPORT/sub
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
new changesets be090ea66256:322ea90975df
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local2
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 1 changesets, 3 total revisions
checking subrepo links
$ cat a
a
$ hg paths
default = static-http://localhost:$HGPORT/
test with empty repo (issue965)
$ cd ..
$ hg init remotempty
$ hg clone static-http://localhost:$HGPORT/remotempty local3
no changes found
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local3
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
0 files, 0 changesets, 0 total revisions
$ hg paths
default = static-http://localhost:$HGPORT/remotempty
test with non-repo
$ cd ..
$ mkdir notarepo
$ hg clone static-http://localhost:$HGPORT/notarepo local3
abort: 'http://localhost:$HGPORT/notarepo' does not appear to be an hg repository!
[255]
Clone with tags and branches works
$ hg init remote-with-names
$ cd remote-with-names
$ echo 0 > foo
$ hg -q commit -A -m initial
$ echo 1 > foo
$ hg commit -m 'commit 1'
$ hg -q up 0
$ hg branch mybranch
marked working directory as branch mybranch
(branches are permanent and global, did you want a bookmark?)
$ echo 2 > foo
$ hg commit -m 'commit 2 (mybranch)'
$ hg tag -r 1 'default-tag'
$ hg tag -r 2 'branch-tag'
$ cd ..
$ hg clone static-http://localhost:$HGPORT/remote-with-names local-with-names
requesting all changes
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files (+1 heads)
new changesets 68986213bd44:0c325bd2b5a7
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Clone a specific branch works
$ hg clone -r mybranch static-http://localhost:$HGPORT/remote-with-names local-with-names-branch
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 2 files
new changesets 68986213bd44:0c325bd2b5a7
updating to branch mybranch
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
Clone a specific tag works
$ hg clone -r default-tag static-http://localhost:$HGPORT/remote-with-names local-with-names-tag
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets 68986213bd44:4ee3fcef1c80
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ killdaemons.py
List of files accessed over HTTP:
$ cat server.log | sed -n -e 's|.*GET \(/[^ ]*\).*|\1|p' | sort -u
/.hg/bookmarks
/.hg/bookmarks.current
/.hg/cache/hgtagsfnodes1
/.hg/cache/rbc-names-v1
/.hg/cache/rbc-revs-v1
/.hg/requires
/.hg/store/00changelog.i
/.hg/store/00manifest.i
/.hg/store/data/%7E2ehgsub.i
/.hg/store/data/%7E2ehgsubstate.i
/.hg/store/data/a.i
/notarepo/.hg/00changelog.i
/notarepo/.hg/requires
/remote-with-names/.hg/bookmarks
/remote-with-names/.hg/bookmarks.current
/remote-with-names/.hg/cache/branch2-served
/remote-with-names/.hg/cache/hgtagsfnodes1
/remote-with-names/.hg/cache/rbc-names-v1
/remote-with-names/.hg/cache/rbc-revs-v1
/remote-with-names/.hg/cache/tags2-served
/remote-with-names/.hg/localtags
/remote-with-names/.hg/requires
/remote-with-names/.hg/store/00changelog.i
/remote-with-names/.hg/store/00manifest.i
/remote-with-names/.hg/store/data/%7E2ehgtags.i
/remote-with-names/.hg/store/data/foo.i
/remote/.hg/bookmarks
/remote/.hg/bookmarks.current
/remote/.hg/cache/branch2-base
/remote/.hg/cache/branch2-immutable
/remote/.hg/cache/branch2-served
/remote/.hg/cache/hgtagsfnodes1
/remote/.hg/cache/rbc-names-v1
/remote/.hg/cache/rbc-revs-v1
/remote/.hg/cache/tags2-served
/remote/.hg/localtags
/remote/.hg/requires
/remote/.hg/store/00changelog.i
/remote/.hg/store/00manifest.i
/remote/.hg/store/data/%7E2edotfile%20with%20spaces.i
/remote/.hg/store/data/%7E2ehgtags.i
/remote/.hg/store/data/bar.i
/remote/.hg/store/data/quux.i
/remotempty/.hg/bookmarks
/remotempty/.hg/bookmarks.current
/remotempty/.hg/requires
/remotempty/.hg/store/00changelog.i
/remotempty/.hg/store/00manifest.i
/sub/.hg/bookmarks
/sub/.hg/bookmarks.current
/sub/.hg/cache/hgtagsfnodes1
/sub/.hg/cache/rbc-names-v1
/sub/.hg/cache/rbc-revs-v1
/sub/.hg/requires
/sub/.hg/store/00changelog.i
/sub/.hg/store/00manifest.i
/sub/.hg/store/data/%7E2ehgtags.i
/sub/.hg/store/data/test.i