view tests/test-narrow-pull.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

  $ . "$TESTDIR/narrow-library.sh"

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [narrow]
  > serveellipses=True
  > EOF
  $ for x in `$TESTDIR/seq.py 10`
  > do
  >   echo $x > "f$x"
  >   hg add "f$x"
  >   hg commit -m "Commit f$x"
  > done
  $ cd ..

narrow clone a couple files, f2 and f8

  $ hg clone --narrow ssh://user@dummy/master narrow --include "f2" --include "f8"
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 2 changes to 2 files
  new changesets *:* (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow
  $ ls
  f2
  f8
  $ cat f2 f8
  2
  8

  $ cd ..

change every upstream file twice

  $ cd master
  $ for x in `$TESTDIR/seq.py 10`
  > do
  >   echo "update#1 $x" >> "f$x"
  >   hg commit -m "Update#1 to f$x" "f$x"
  > done
  $ for x in `$TESTDIR/seq.py 10`
  > do
  >   echo "update#2 $x" >> "f$x"
  >   hg commit -m "Update#2 to f$x" "f$x"
  > done
  $ cd ..

look for incoming changes

  $ cd narrow
  $ hg incoming --limit 3
  comparing with ssh://user@dummy/master
  searching for changes
  changeset:   5:ddc055582556
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Update#1 to f1
  
  changeset:   6:f66eb5ad621d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Update#1 to f2
  
  changeset:   7:c42ecff04e99
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Update#1 to f3
  

Interrupting the pull is safe
  $ hg --config hooks.pretxnchangegroup.bad=false pull -q
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.bad hook exited with status 1
  [255]
  $ hg id
  223311e70a6f tip

pull new changes down to the narrow clone. Should get 8 new changesets: 4
relevant to the narrow spec, and 4 ellipsis nodes gluing them all together.

  $ hg pull
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 4 changes to 2 files
  new changesets *:* (glob)
  (run 'hg update' to get a working copy)
  $ hg log -T '{rev}: {desc}\n'
  13: Update#2 to f10
  12: Update#2 to f8
  11: Update#2 to f7
  10: Update#2 to f2
  9: Update#2 to f1
  8: Update#1 to f8
  7: Update#1 to f7
  6: Update#1 to f2
  5: Update#1 to f1
  4: Commit f10
  3: Commit f8
  2: Commit f7
  1: Commit f2
  0: Commit f1
  $ hg update tip
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

add a change and push it

  $ echo "update#3 2" >> f2
  $ hg commit -m "Update#3 to f2" f2
  $ hg log f2 -T '{rev}: {desc}\n'
  14: Update#3 to f2
  10: Update#2 to f2
  6: Update#1 to f2
  1: Commit f2
  $ hg push
  pushing to ssh://user@dummy/master
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ cd ..

  $ cd master
  $ hg log f2 -T '{rev}: {desc}\n'
  30: Update#3 to f2
  21: Update#2 to f2
  11: Update#1 to f2
  1: Commit f2
  $ hg log -l 3 -T '{rev}: {desc}\n'
  30: Update#3 to f2
  29: Update#2 to f10
  28: Update#2 to f9

Can pull into repo with a single commit

  $ cd ..
  $ hg clone -q --narrow ssh://user@dummy/master narrow2 --include "f1" -r 0
  $ cd narrow2
  $ hg pull -q -r 1
  transaction abort!
  rollback completed
  abort: pull failed on remote
  [255]

Can use 'hg share':
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > share=
  > EOF

  $ cd ..
  $ hg share narrow2 narrow2-share
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow2-share
  $ hg status

We should also be able to unshare without breaking everything:
  $ hg unshare
  devel-warn: write with no wlock: "narrowspec" at: */hgext/narrow/narrowrepo.py:* (unsharenarrowspec) (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 1 changesets, 1 total revisions