Most of the tests in this file require a Dulwich server, so let’s start one:
>>> from dulwich.repo import Repo
>>> from dulwich.server import DictBackend, TCPGitServer
>>> import threading
>>> repo = Repo.init("remote", mkdir=True)
>>> cid = repo.do_commit("message", committer="Jelmer <jelmer@samba.org>")
>>> backend = DictBackend({'/': repo})
>>> dul_server = TCPGitServer(backend, 'localhost', 0)
>>> threading.Thread(target=dul_server.serve).start()
>>> server_address, server_port = dul_server.socket.getsockname()
The interface for remote Git repositories is different from that for local repositories.
The Git smart server protocol provides three basic operations:
- upload-pack - provides a pack with objects requested by the client
- receive-pack - imports a pack with objects provided by the client
- upload-archive - provides a tarball with the contents of a specific revision
The smart server protocol can be accessed over either plain TCP (git://), SSH (git+ssh://) or tunneled over HTTP (http://).
Dulwich provides support for accessing remote repositories in dulwich.client. To create a new client, you can either construct one manually:
>>> from dulwich.client import TCPGitClient
>>> client = TCPGitClient(server_address, server_port)
The client object can then be used to retrieve a pack. The fetch_pack method takes a determine_wants callback argument, which allows the client to determine which objects it wants to end up with:
>>> def determine_wants(refs):
... # retrieve all objects
... return refs.values()
Another required object is a “graph walker”, which is used to determine which objects that the client already has should not be sent again by the server. Here in the tutorial we’ll just use a dummy graph walker which claims that the client doesn’t have any objects:
>>> class DummyGraphWalker(object):
... def ack(self, sha): pass
... def next(self): pass
With the determine_wants function in place, we can now fetch a pack, which we will write to a StringIO object:
>>> from cStringIO import StringIO
>>> f = StringIO()
>>> remote_refs = client.fetch_pack("/", determine_wants,
... DummyGraphWalker(), pack_data=f.write)
f will now contain a full pack file:
>>> f.getvalue()[:4]
'PACK'
It also possible to fetch from a remote repository into a local repository, in which case dulwich takes care of providing the right graph walker, and importing the received pack file into the local repository:
>>> from dulwich.repo import Repo
>>> local = Repo.init("local", mkdir=True)
>>> remote_refs = client.fetch("/", local)
Let’s show down the server now that all tests have been run:
>>> dul_server.shutdown()