Add httpng.py state

This patch adds new httpng.py which is a copy of http.py
from Salt 2017. It contains wait_for_successful_query method which
is needed in order to wait for init of OpenStack API interfaces
like Cinder API, Designate API, etc.

Change-Id: I5b4e526392df6dc0b9103a203937dbab31e0d301
Related-Prod: PROD-17170

_states/httpng.py

@@ -0,0 +1,172 @@
+# -*- coding: utf-8 -*-
+'''
+HTTP monitoring states
+
+Perform an HTTP query and statefully return the result
+
+TODO: This is a copy of upstream state file: https://github.com/saltstack/salt/blob/2017.7.3/salt/states/http.py.
+It have to be removed when MCP Salt will be upgreaded up to 2017 or higher.
+
+.. versionadded:: 2015.5.0
+'''
+
+# Import python libs
+from __future__ import absolute_import
+import re
+import logging
+import time
+
+__monitor__ = [
+        'query',
+        ]
+
+log = logging.getLogger(__name__)
+
+
+def query(name, match=None, match_type='string', status=None, wait_for=None, **kwargs):
+    '''
+    Perform an HTTP query and statefully return the result
+
+    .. versionadded:: 2015.5.0
+
+    name
+        The name of the query.
+
+    match
+        Specifies a pattern to look for in the return text. By default, this will
+        perform a string comparison of looking for the value of match in the return
+        text.
+
+    match_type
+        Specifies the type of pattern matching to use. Default is ``string``, but
+        can also be set to ``pcre`` to use regular expression matching if a more
+        complex pattern matching is required.
+
+        .. note::
+
+            Despite the name of ``match_type`` for this argument, this setting
+            actually uses Python's ``re.search()`` function rather than Python's
+            ``re.match()`` function.
+
+    status
+        The status code for a URL for which to be checked. Can be used instead of
+        or in addition to the ``match`` setting.
+
+    If both ``match`` and ``status`` options are set, both settings will be checked.
+    However, note that if only one option is ``True`` and the other is ``False``,
+    then ``False`` will be returned. If this case is reached, the comments in the
+    return data will contain troubleshooting information.
+
+    For more information about the ``http.query`` state, refer to the
+    :ref:`HTTP Tutorial <tutorial-http>`.
+
+    .. code-block:: yaml
+
+        query_example:
+          http.query:
+            - name: 'http://example.com/'
+            - status: 200
+
+    '''
+    # Monitoring state, but changes may be made over HTTP
+    ret = {'name': name,
+           'result': None,
+           'comment': '',
+           'changes': {},
+           'data': {}}  # Data field for monitoring state
+
+    if match is None and status is None:
+        ret['result'] = False
+        ret['comment'] += (
+            ' Either match text (match) or a status code (status) is required.'
+        )
+        return ret
+
+    if 'decode' not in kwargs:
+        kwargs['decode'] = False
+    kwargs['text'] = True
+    kwargs['status'] = True
+    if __opts__['test']:
+        kwargs['test'] = True
+
+    if wait_for:
+        data = __salt__['http.wait_for_successful_query'](name, wait_for=wait_for, **kwargs)
+    else:
+        data = __salt__['http.query'](name, **kwargs)
+
+    if match is not None:
+        if match_type == 'string':
+            if match in data.get('text', ''):
+                ret['result'] = True
+                ret['comment'] += ' Match text "{0}" was found.'.format(match)
+            else:
+                ret['result'] = False
+                ret['comment'] += ' Match text "{0}" was not found.'.format(match)
+        elif match_type == 'pcre':
+            if re.search(match, data.get('text', '')):
+                ret['result'] = True
+                ret['comment'] += ' Match pattern "{0}" was found.'.format(match)
+            else:
+                ret['result'] = False
+                ret['comment'] += ' Match pattern "{0}" was not found.'.format(match)
+
+    if status is not None:
+        if data.get('status', '') == status:
+            ret['comment'] += 'Status {0} was found, as specified.'.format(status)
+            if ret['result'] is None:
+                ret['result'] = True
+        else:
+            ret['comment'] += 'Status {0} was not found, as specified.'.format(status)
+            ret['result'] = False
+
+    if __opts__['test'] is True:
+        ret['result'] = None
+        ret['comment'] += ' (TEST MODE'
+        if 'test_url' in kwargs:
+            ret['comment'] += ', TEST URL WAS: {0}'.format(kwargs['test_url'])
+        ret['comment'] += ')'
+
+    ret['data'] = data
+    return ret
+
+
+def wait_for_successful_query(name, wait_for=300, **kwargs):
+    '''
+    Like query but, repeat and wait until match/match_type or status is fulfilled. State returns result from last
+    query state in case of success or if no successful query was made within wait_for timeout.
+
+    name
+        The name of the query.
+
+    wait_for
+        Total time to wait for requests that succeed.
+
+    request_interval
+        Optional interval to delay requests by N seconds to reduce the number of requests sent.
+
+    .. note::
+
+        All other arguements are passed to the http.query state.
+    '''
+    starttime = time.time()
+
+    while True:
+        caught_exception = None
+        ret = None
+        try:
+            ret = query(name, **kwargs)
+            if ret['result']:
+                return ret
+        except Exception as exc:
+            caught_exception = exc
+
+        if time.time() > starttime + wait_for:
+            if not ret and caught_exception:
+                # workaround pylint bug https://www.logilab.org/ticket/3207
+                raise caught_exception  # pylint: disable=E0702
+            return ret
+        else:
+            # Space requests out by delaying for an interval
+            if 'request_interval' in kwargs:
+                log.debug("delaying query for {0} seconds.".format(kwargs['request_interval']))
+                time.sleep(kwargs['request_interval'])