view tests/test-convert-tla.t @ 37048:fc5e261915b9

wireproto: require POST for all HTTPv2 requests

Wire protocol version 1 transfers argument data via request
headers by default. This has historically caused problems because
servers institute limits on the length of individual HTTP headers
as well as the total size of all request headers. Mercurial servers
can advertise the maximum length of an individual header. But
there's no guarantee any intermediate HTTP agents will accept
headers up to that length.

In the existing wire protocol, server operators typically also
key off the HTTP request method to implement authentication.
For example, GET requests translate to read-only requests and
can be allowed. But read-write commands must use POST and require
authentication. This has typically worked because the only wire
protocol commands that use POST modify the repo (e.g. the
"unbundle" command).

There is an experimental feature to enable clients to transmit
argument data via POST request bodies. This is technically a
better and more robust solution. But we can't enable it by default
because of servers assuming POST means write access.

In version 2 of the wire protocol, the permissions of a request
are encoded in the URL. And with it being a new protocol in a new
URL space, we're not constrained by backwards compatibility
requirements.

This commit adopts the technically superior mechanism of using
HTTP request bodies to send argument data by requiring POST for
all commands. Strictly speaking, it may be possible to send
request bodies on GET requests. But my experience is that not all
HTTP stacks support this. POST pretty much always works. Using POST
for read-only operations does sacrifice some RESTful design
purity. But this API cares about practicality, not about being
in Roy T. Fielding's REST ivory tower.

There's a chance we may relax this restriction in the future. But
for now, I want to see how far we can get with a POST only API.

Differential Revision: https://phab.mercurial-scm.org/D2837

#require tla symlink

  $ tla my-id "mercurial <[e-mail]>"
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH

create tla archive

  $ tla make-archive tla@mercurial--convert `pwd`/hg-test-convert-tla

initialize tla repo

  $ mkdir tla-repo
  $ cd tla-repo/
  $ tla init-tree tla@mercurial--convert/tla--test--0
  $ tla import
  * creating version tla@mercurial--convert/tla--test--0
  * imported tla@mercurial--convert/tla--test--0

create initial files

  $ echo 'this is a file' > a
  $ tla add a
  $ mkdir src
  $ tla add src
  $ cd src
  $ dd count=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla add b
  $ tla commit -s "added a file, src and src/b (binary)"
  A/ .arch-ids
  A/ src
  A/ src/.arch-ids
  A  .arch-ids/a.id
  A  a
  A  src/.arch-ids/=id
  A  src/.arch-ids/b.id
  A  src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--base-0 => tla--test--0--patch-1)
  * committed tla@mercurial--convert/tla--test--0--patch-1

create link file and modify a

  $ ln -s ../a a-link
  $ tla add a-link
  $ echo 'this a modification to a' >> ../a
  $ tla commit -s "added link to a and modify a"
  A  src/.arch-ids/a-link.id
  A  src/a-link
  M  a
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-1 => tla--test--0--patch-2)
  * committed tla@mercurial--convert/tla--test--0--patch-2

create second link and modify b

  $ ln -s ../a a-link-2
  $ tla add a-link-2
  $ dd count=1 seek=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla commit -s "added second link and modify b"
  A  src/.arch-ids/a-link-2.id
  A  src/a-link-2
  Mb src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-2 => tla--test--0--patch-3)
  * committed tla@mercurial--convert/tla--test--0--patch-3

b file to link and a-link-2 to regular file

  $ rm -f a-link-2
  $ echo 'this is now a regular file' > a-link-2
  $ ln -sf ../a b
  $ tla commit -s "file to link and link to file test"
  fl src/b
  lf src/a-link-2
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-3 => tla--test--0--patch-4)
  * committed tla@mercurial--convert/tla--test--0--patch-4

move a-link-2 file and src directory

  $ cd ..
  $ tla mv src/a-link-2 c
  $ tla mv src test
  $ tla commit -s "move and rename a-link-2 file and src directory"
  D/ src/.arch-ids
  A/ test/.arch-ids
  /> src	test
  => src/.arch-ids/a-link-2.id	.arch-ids/c.id
  => src/a-link-2	c
  => src/.arch-ids/=id	test/.arch-ids/=id
  => src/.arch-ids/a-link.id	test/.arch-ids/a-link.id
  => src/.arch-ids/b.id	test/.arch-ids/b.id
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-4 => tla--test--0--patch-5)
  * committed tla@mercurial--convert/tla--test--0--patch-5
  $ cd ..

converting tla repo to Mercurial

  $ hg convert tla-repo tla-repo-hg
  initializing destination tla-repo-hg repository
  analyzing tree version tla@mercurial--convert/tla--test--0...
  scanning source...
  sorting...
  converting...
  5 initial import
  4 added a file, src and src/b (binary)
  3 added link to a and modify a
  2 added second link and modify b
  1 file to link and link to file test
  0 move and rename a-link-2 file and src directory
  $ tla register-archive -d tla@mercurial--convert
  $ glog()
  > {
  >     hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
  > }

show graph log

  $ glog -R tla-repo-hg
  o  5 "move and rename a-link-2 file and src directory" files: c src/a-link src/a-link-2 src/b test/a-link test/b
  |
  o  4 "file to link and link to file test" files: src/a-link-2 src/b
  |
  o  3 "added second link and modify b" files: src/a-link-2 src/b
  |
  o  2 "added link to a and modify a" files: a src/a-link
  |
  o  1 "added a file, src and src/b (binary)" files: a src/b
  |
  o  0 "initial import" files:
  
  $ hg up -q -R tla-repo-hg
  $ hg -R tla-repo-hg manifest --debug
  c4072c4b72e1cabace081888efa148ee80ca3cbb 644   a
  0201ac32a3a8e86e303dff60366382a54b48a72e 644   c
  c0067ba5ff0b7c9a3eb17270839d04614c435623 644 @ test/a-link
  375f4263d86feacdea7e3c27100abd1560f2a973 644 @ test/b