view hgext/zeroconf/__init__.py @ 44682:9ce613d648de

rust-chg: add config validation and process returned instructions

This is the reimplementation of runinstructions() and main() in chg.c.

In Rust version, we only pass in early arguments to the server as the locator
doesn't know the full arguments. This should be fine since these arguments
are just passed in to _earlyparseopts() and _parseconfig(), which means the
server doesn't need full arguments.

Another difference is the handling of the "exit <code>" instruction. In Rust
version, we can simply reuse the connection instead of "exit(code)" as the
command error isn't displayed yet. That's because the client-side stdio is not
attached until the connection is validated. This behavior is cleaner than C,
but it also means that the early server exception wouldn't be propagated to
client because stderr isn't attached. So we might have to reconsider when to
attach/detach the server stdio.

Differential Revision: https://phab.mercurial-scm.org/D8381

# 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

The zeroconf extension will advertise :hg:`serve` instances over
DNS-SD so that they can be discovered using the :hg:`paths` command
without knowing the server's 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,
    pycompat,
    rcutil,
    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 = b'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(
        b'_http._tcp.local.',
        pycompat.bytestr(name + '._http._tcp.local.'),
        server=host,
        port=port,
        properties={b'description': desc, b'path': b"/" + path},
        address=localip,
        weight=0,
        priority=0,
    )
    server.registerService(svc)

    # advertise to Mercurial clients
    svc = Zeroconf.ServiceInfo(
        b'_hg._tcp.local.',
        pycompat.bytestr(name + '._hg._tcp.local.'),
        server=host,
        port=port,
        properties={b'description': desc, b'path': b"/" + 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(b"web", b"prefix", b"").strip(b'/')
            desc = repo.ui.config(b"web", b"description")
            if not desc:
                desc = name
        publish(name, desc, path, port)
    else:
        # webdir
        prefix = app.ui.config(b"web", b"prefix", b"").strip(b'/') + b'/'
        for repo, path in repos:
            u = app.ui.copy()
            if rcutil.use_repo_hgrc():
                u.readconfig(os.path.join(path, b'.hg', b'hgrc'))
            name = os.path.basename(repo)
            path = (prefix + repo).strip(b'/')
            desc = u.config(b'web', b'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, b"_hg._tcp.local.", l)
    time.sleep(1)
    server.close()
    for value in l.found.values():
        name = value.name[: value.name.index(b'.')]
        url = "http://%s:%s%s" % (
            socket.inet_ntoa(value.address),
            value.port,
            value.properties.get("path", "/"),
        )
        yield b"zc-" + name, pycompat.bytestr(url)


def config(orig, self, section, key, *args, **kwargs):
    if section == b"paths" and key.startswith(b"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 == b"paths":
        repos += getzcpaths()
    return repos


def configsuboptions(orig, self, section, name, *args, **kwargs):
    opt, sub = orig(self, section, name, *args, **kwargs)
    if section == b"paths" and name.startswith(b"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, b'_runcommand', cleanupafterdispatch)

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