bundle dnspython in support/; resolving is always green

Fixes installation issue when older dnspython is present in system packages
#341

.travis.yml

@@ -6,29 +6,24 @@ env:
     - TOX_ENV=py26-epolls
     - TOX_ENV=py26-poll
     - TOX_ENV=py26-selects
-    - TOX_ENV=py27-dns
     - TOX_ENV=py27-epolls
     - TOX_ENV=py27-poll
     - TOX_ENV=py27-selects
     - TOX_ENV=py33-epolls
     - TOX_ENV=py33-poll
     - TOX_ENV=py33-selects
-    - TOX_ENV=py34-dns
     - TOX_ENV=py34-epolls
     - TOX_ENV=py34-poll
     - TOX_ENV=py34-selects
-    - TOX_ENV=py35-dns
     - TOX_ENV=py35-epolls
     - TOX_ENV=py35-poll
     - TOX_ENV=py35-selects
-    - TOX_ENV=pypy-dns
     - TOX_ENV=pypy-epolls
     - TOX_ENV=pypy-poll
     - TOX_ENV=pypy-selects
 matrix:
   fast_finish: true
   allow_failures:
-    - env: TOX_ENV=pypy-dns
     - env: TOX_ENV=pypy-epolls
     - env: TOX_ENV=pypy-poll
     - env: TOX_ENV=pypy-selects

bin/pull-dnspython

@@ -0,0 +1,13 @@
+#!/bin/bash -eux
+cd "$( dirname "${BASH_SOURCE[0]}" )/.."
+version=${1-188aa701a6826c607da0624e31a8c4618d0a8017}
+upstream_path=./dnspython-${version}
+if [[ ! -d "${upstream_path}" ]]; then
+  curl -L -odnspython.zip "https://github.com/rthalley/dnspython/archive/${version}.zip"
+  unzip dnspython.zip
+  rm dnspython.zip
+fi
+rm -rf eventlet/support/dns
+# patch --directory=eventlet/support -p1 --normal --forward -r/dev/null <./dns.patch
+mv ${upstream_path}/dns eventlet/support/
+rm -rf ${upstream_path}

eventlet/green/socket.py

@@ -1,38 +1,30 @@
 import os
 import sys
+import warnings
 
 __import__('eventlet.green._socket_nodns')
 __socket = sys.modules['eventlet.green._socket_nodns']
 
 __all__ = __socket.__all__
-__patched__ = __socket.__patched__ + ['gethostbyname', 'getaddrinfo', 'create_connection', ]
+__patched__ = __socket.__patched__ + ['gethostbyname', 'getaddrinfo', 'create_connection']
 
 from eventlet.patcher import slurp_properties
 slurp_properties(__socket, globals(), srckeys=dir(__socket))
 
 
-greendns = None
-if os.environ.get("EVENTLET_NO_GREENDNS", '').lower() != "yes":
-    try:
-        from eventlet.support import greendns
-    except ImportError as ex:
-        try:
-            import dns
-        except ImportError:
-            # greendns import failed because we don't have dnspython - all is well,
-            # that's why we have the conditional import
-            pass
-        else:
-            # If, however, dnspython is importable yet greendns can't be imported
-            # this suggests there's another issue (like an import cycle)
-            raise
+if os.environ.get("EVENTLET_NO_GREENDNS", '').lower() == "yes":
+    warnings.warn(
+        'EVENTLET_NO_GREENDNS is noop, dnspython is bundled and DNS resolution is always green',
+        DeprecationWarning,
+        stacklevel=2,
+    )
 
-if greendns:
-    gethostbyname = greendns.gethostbyname
-    getaddrinfo = greendns.getaddrinfo
-    gethostbyname_ex = greendns.gethostbyname_ex
-    getnameinfo = greendns.getnameinfo
-    __patched__ = __patched__ + ['gethostbyname_ex', 'getnameinfo']
+from eventlet.support import greendns
+gethostbyname = greendns.gethostbyname
+getaddrinfo = greendns.getaddrinfo
+gethostbyname_ex = greendns.gethostbyname_ex
+getnameinfo = greendns.getnameinfo
+__patched__ = __patched__ + ['gethostbyname_ex', 'getnameinfo']
 
 
 def create_connection(address,

eventlet/support/dns/__init__.py

@@ -0,0 +1,54 @@
+# Copyright (C) 2003-2007, 2009, 2011 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""dnspython DNS toolkit"""
+
+__all__ = [
+    'dnssec',
+    'e164',
+    'edns',
+    'entropy',
+    'exception',
+    'flags',
+    'hash',
+    'inet',
+    'ipv4',
+    'ipv6',
+    'message',
+    'name',
+    'namedict',
+    'node',
+    'opcode',
+    'query',
+    'rcode',
+    'rdata',
+    'rdataclass',
+    'rdataset',
+    'rdatatype',
+    'renderer',
+    'resolver',
+    'reversename',
+    'rrset',
+    'set',
+    'tokenizer',
+    'tsig',
+    'tsigkeyring',
+    'ttl',
+    'rdtypes',
+    'update',
+    'version',
+    'wiredata',
+    'zone',
+]

eventlet/support/dns/_compat.py

@@ -0,0 +1,47 @@
+import sys
+import decimal
+from decimal import Context
+
+if sys.version_info > (3,):
+    long = int
+    xrange = range
+else:
+    long = long  # pylint: disable=long-builtin
+    xrange = xrange  # pylint: disable=xrange-builtin
+
+# unicode / binary types
+if sys.version_info > (3,):
+    text_type = str
+    binary_type = bytes
+    string_types = (str,)
+    unichr = chr
+    def maybe_decode(x):
+        return x.decode()
+    def maybe_encode(x):
+        return x.encode()
+else:
+    text_type = unicode  # pylint: disable=unicode-builtin, undefined-variable
+    binary_type = str
+    string_types = (
+        basestring,  # pylint: disable=basestring-builtin, undefined-variable
+    )
+    unichr = unichr  # pylint: disable=unichr-builtin
+    def maybe_decode(x):
+        return x
+    def maybe_encode(x):
+        return x
+
+
+def round_py2_compat(what):
+    """
+    Python 2 and Python 3 use different rounding strategies in round(). This
+    function ensures that results are python2/3 compatible and backward
+    compatible with previous py2 releases
+    :param what: float
+    :return: rounded long
+    """
+    d = Context(
+        prec=len(str(long(what))),  # round to integer with max precision
+        rounding=decimal.ROUND_HALF_UP
+    ).create_decimal(str(what))  # str(): python 2.6 compat
+    return long(d)