view tests/test-push-checkheads-superceed-A5.t @ 37147:a2566597acb5

lfs: add basic routing for the server side wire protocol processing

The recent hgweb refactoring yielded a clean point to wrap a function that could
handle this, so I moved the routing for this out of the core.  While not an hg
wire protocol, this seems logically close enough.  For now, these handlers do
nothing other than check permissions.

The protocol requires support for PUT requests, so that has been added to the
core, and funnels into the same handler as GET and POST.  The permission
checking code was assuming that anything not checking 'pull' or None ops should
be using POST.  But that breaks the upload check if it checks 'push'.  So I
invented a new 'upload' permission, and used it to avoid the mandate to POST.  A
function wrap point could be added, but security code should probably stay
grouped together.  Given that anything not 'pull' or None was requiring POST,
the comment on hgweb.common.permhooks is probably wrong- there is no 'read'.

The rationale for the URIs is that the spec for the Batch API[1] defines the URL
as the LFS server url + '/objects/batch'.  The default git URLs are:

    Git remote: https://git-server.com/foo/bar
    LFS server: https://git-server.com/foo/bar.git/info/lfs
    Batch API: https://git-server.com/foo/bar.git/info/lfs/objects/batch

'.git/' seems like it's not something a user would normally track.  If we adhere
to how git defines the URLs, then the hg-git extension should be able to talk to
a git based server without any additional work.

The URI for the transfer requests starts with '.hg/' to ensure that there are no
conflicts with tracked files.  Since these are handed out by the Batch API, we
can change this at any point in the future.  (Specifically, it might be a good
idea to use something under the proposed /api/ namespace.)  In any case, no
files are stored at these locations in the repository directory.

I started a new module for this because it seems like a good idea to keep all of
the security sensitive server side code together.  There's also an issue with
`hg verify` in that it will want to download *all* blobs in order to run.
Sadly, there's no way in the protocol to ask the server to verify the content of
a blob it may have.  (The verify action is for storing files on a 3rd party
server, and then informing the LFS server when that completes.)  So we may end
up implementing a custom transfer adapter that simply indicates if the blobs are
valid, and fall back to basic transfers for non-hg servers.  In other words,
this code is likely to get bigger before this is made non-experimental.

[1] https://github.com/git-lfs/git-lfs/blob/master/docs/api/batch.md

====================================
Testing head checking code: Case A-5
====================================

Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.

This case is part of a series of tests checking this behavior.

Category A: simple case involving a branch being superceeded by another.
TestCase 5: New changeset as parent of the successor

.. old-state:
..
.. * 1-changeset branch
..
.. new-state:
..
.. * 2rchangeset branch, head is a successor, but other is new
..
.. expected-result:
..
.. * push allowed
..
.. graph-summary:
..
..   A ø⇠◔ A'
..     | |
..     | ◔ B
..     |/
..     ●

  $ . $TESTDIR/testlib/push-checkheads-util.sh

Test setup
----------

  $ mkdir A5
  $ cd A5
  $ setuprepos
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd client
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit B0
  created new head
  $ mkcommit A1
  $ hg debugobsolete `getid "desc(A0)" ` `getid "desc(A1)"`
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  ba93660aff8d (draft): A1
  |
  o  74ff5441d343 (draft): B0
  |
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

Actual testing
--------------

  $ hg push
  pushing to $TESTTMP/A5/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  1 new obsolescence markers
  obsoleted 1 changesets

  $ cd ../..