Export-to-branch script fails on lp-hosted protocol

[Jeroen T. Vermeulen]

The translations-export-to-branch.py script fails while trying to access a branch.

The message is: Failure: Unsupported protocol for url "lp-hosted:///~jtv/+junk/test"

Full output: https://pastebin.canonical.com/19744/

[Jeroen T. Vermeulen (jtv)]

Notes from call with mwhudson:
 * This may be the first LP script that writes to branches. As if DirectBranchCommit wasn't breaking enough new ground...
 * lp-hosted is acessible only from the code-hosting server, so that's where the script must run.
 * The script may need to call requestMirror (sp?) after writing to a hosted branch.
 * Need to set up a server created by get_multi_server(write_hosted=True). Tear it down after use.
 * There may be problems with stacked branches, which will become a lot more popular with bzr 2.0.
 * Instead of BzrBranch.open(self.db_branch.getPullURL()), say BranchMirrorer(HostedBranchPolicy(), None, None).open(self.db_branch.getPullURL())
 * Various parts of the codehosting stuff we use here need refactoring.

[Jeroen T. Vermeulen (jtv)]

HostedBranchPolicy is internal to the puller worker, so currently I can't get at it. Also, the BranchMirrorer and its policy classes are in the puller, when here I'm trying to use them for very different purposes.

So I propose to build a BranchMirrorer factory that takes a BranchType (plus BranchMirrorer constructor arguments) and returns a BranchMirrorer with the right policy. The policy classes can live inside the factory's module. It's to be based on PullerWorker._checkerForBranchType but also let me do what I need here.

jml says to build it in branchfs.py, and reexport it from vfs/__init__.py.

[Данило Шеган (danilo)]

Landed in devel/8939.

[Jeroen T. Vermeulen (jtv)]

Merged into db-devel 8289. Not on staging yet.