annotate hgext/zeroconf/__init__.py @ 35506:fa865878a849

lfs: show a friendly message when pushing lfs to a server without lfs enabled

Upfront disclaimer: I don't know anything about the wire protocol, and this was
pretty much cargo-culted from largefiles, and then clonebundles, since it seems
more modern.  I was surprised that exchange.push() will ensure all of the proper
requirements when exchanging between two local repos, but doesn't care when one
is remote.

All this new capability marker does is inform the client that the extension is
enabled remotely.  It may or may not contain commits with external blobs.

Open issues:

  - largefiles uses 'largefiles=serve' for its capability.  Someday I hope to
    be able to push lfs blobs to an `hg serve` instance.  That will probably
    require a distinct capability.  Should it change to '=serve' then?  Or just
    add an 'lfs-serve' capability then?

  - The flip side of this is more complicated.  It looks like largefiles adds an
    'lheads' command for the client to signal to the server that the extension
    is loaded.  That is then converted to 'heads' and sent through the normal
    wire protocol plumbing.  A client using the 'heads' command directly is
    kicked out with a message indicating that the largefiles extension must be
    loaded.  We could do similar with 'lfsheads', but then a repo with both
    largefiles and lfs blobs can't be pushed over the wire.  Hopefully somebody
    with more wire protocol experience can think of something else.  I see
    'x-hgarg-1' on some commands in the tests, but not on heads, and didn't dig
    any further.

# zeroconf.py - zeroconf support for Mercurial
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''discover and advertise repositories on the local network

Zeroconf-enabled repositories will be announced in a network without
the need to configure a server or a service. They can be discovered
without knowing their actual IP address.

To allow other people to discover your repository using run
:hg:`serve` in your repository::

  $ cd test
  $ hg serve

You can discover Zeroconf-enabled repositories by running
:hg:`paths`::

  $ hg paths
  zc-test = http://example.com:8000/test
'''
from __future__ import absolute_import

import os
import socket
import time

from . import Zeroconf
from mercurial import (
    dispatch,
    encoding,
    extensions,
    hg,
    ui as uimod,
)
from mercurial.hgweb import (
    server as servermod
)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

# publish

server = None
localip = None

def getip():
    # finds external-facing interface without sending any packets (Linux)
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect(('1.0.0.1', 0))
        ip = s.getsockname()[0]
        return ip
    except socket.error:
        pass

    # Generic method, sometimes gives useless results
    try:
        dumbip = socket.gethostbyaddr(socket.gethostname())[2][0]
        if ':' in dumbip:
            dumbip = '127.0.0.1'
        if not dumbip.startswith('127.'):
            return dumbip
    except (socket.gaierror, socket.herror):
        dumbip = '127.0.0.1'

    # works elsewhere, but actually sends a packet
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect(('1.0.0.1', 1))
        ip = s.getsockname()[0]
        return ip
    except socket.error:
        pass

    return dumbip

def publish(name, desc, path, port):
    global server, localip
    if not server:
        ip = getip()
        if ip.startswith('127.'):
            # if we have no internet connection, this can happen.
            return
        localip = socket.inet_aton(ip)
        server = Zeroconf.Zeroconf(ip)

    hostname = socket.gethostname().split('.')[0]
    host = hostname + ".local"
    name = "%s-%s" % (hostname, name)

    # advertise to browsers
    svc = Zeroconf.ServiceInfo('_http._tcp.local.',
                               name + '._http._tcp.local.',
                               server = host,
                               port = port,
                               properties = {'description': desc,
                                             'path': "/" + path},
                               address = localip, weight = 0, priority = 0)
    server.registerService(svc)

    # advertise to Mercurial clients
    svc = Zeroconf.ServiceInfo('_hg._tcp.local.',
                               name + '._hg._tcp.local.',
                               server = host,
                               port = port,
                               properties = {'description': desc,
                                             'path': "/" + path},
                               address = localip, weight = 0, priority = 0)
    server.registerService(svc)

def zc_create_server(create_server, ui, app):
    httpd = create_server(ui, app)
    port = httpd.port

    try:
        repos = app.repos
    except AttributeError:
        # single repo
        with app._obtainrepo() as repo:
            name = app.reponame or os.path.basename(repo.root)
            path = repo.ui.config("web", "prefix", "").strip('/')
            desc = repo.ui.config("web", "description")
            if not desc:
                desc = name
        publish(name, desc, path, port)
    else:
        # webdir
        prefix = app.ui.config("web", "prefix", "").strip('/') + '/'
        for repo, path in repos:
            u = app.ui.copy()
            u.readconfig(os.path.join(path, '.hg', 'hgrc'))
            name = os.path.basename(repo)
            path = (prefix + repo).strip('/')
            desc = u.config('web', 'description')
            if not desc:
                desc = name
            publish(name, desc, path, port)
    return httpd

# listen

class listener(object):
    def __init__(self):
        self.found = {}
    def removeService(self, server, type, name):
        if repr(name) in self.found:
            del self.found[repr(name)]
    def addService(self, server, type, name):
        self.found[repr(name)] = server.getServiceInfo(type, name)

def getzcpaths():
    ip = getip()
    if ip.startswith('127.'):
        return
    server = Zeroconf.Zeroconf(ip)
    l = listener()
    Zeroconf.ServiceBrowser(server, "_hg._tcp.local.", l)
    time.sleep(1)
    server.close()
    for value in l.found.values():
        name = value.name[:value.name.index('.')]
        url = "http://%s:%s%s" % (socket.inet_ntoa(value.address), value.port,
                                  value.properties.get("path", "/"))
        yield "zc-" + name, url

def config(orig, self, section, key, *args, **kwargs):
    if section == "paths" and key.startswith("zc-"):
        for name, path in getzcpaths():
            if name == key:
                return path
    return orig(self, section, key, *args, **kwargs)

def configitems(orig, self, section, *args, **kwargs):
    repos = orig(self, section, *args, **kwargs)
    if section == "paths":
        repos += getzcpaths()
    return repos

def configsuboptions(orig, self, section, name, *args, **kwargs):
    opt, sub = orig(self, section, name, *args, **kwargs)
    if section == "paths" and name.startswith("zc-"):
        # We have to find the URL in the zeroconf paths.  We can't cons up any
        # suboptions, so we use any that we found in the original config.
        for zcname, zcurl in getzcpaths():
            if zcname == name:
                return zcurl, sub
    return opt, sub

def defaultdest(orig, source):
    for name, path in getzcpaths():
        if path == source:
            return name.encode(encoding.encoding)
    return orig(source)

def cleanupafterdispatch(orig, ui, options, cmd, cmdfunc):
    try:
        return orig(ui, options, cmd, cmdfunc)
    finally:
        # we need to call close() on the server to notify() the various
        # threading Conditions and allow the background threads to exit
        global server
        if server:
            server.close()

extensions.wrapfunction(dispatch, '_runcommand', cleanupafterdispatch)

extensions.wrapfunction(uimod.ui, 'config', config)
extensions.wrapfunction(uimod.ui, 'configitems', configitems)
extensions.wrapfunction(uimod.ui, 'configsuboptions', configsuboptions)
extensions.wrapfunction(hg, 'defaultdest', defaultdest)
extensions.wrapfunction(servermod, 'create_server', zc_create_server)