Add junos_system declartive module and other related change (#25859)

* Add junos_system declartive module and other related change

*  junos_system declartive module
*  integration test for junos_system
*  integration test for net_system (junos platform)
*  pep8 fixes for junos modules
*  move to lxml from elementree for xml parsing as it support
   complete set of xpath api's
*  other minor changes

* Fix CI and doc changes

* Fix unit test failures

* Fix typo in import

* Fix import issue for py2.6

* Add missed Element in import

lib/ansible/modules/network/junos/junos_command.py

@@ -104,6 +104,10 @@ options:
     version_added: "2.3"
 requirements:
   - jxmlease
+  - ncclient (>=v0.5.2)
+notes:
+  - This module requires the netconf system service be enabled on
+    the remote device being managed
 """
 
 EXAMPLES = """
@@ -163,17 +167,17 @@ import time
 import re
 import shlex
 
-from functools import partial
-from xml.etree import ElementTree as etree
-from xml.etree.ElementTree import Element, SubElement, tostring
-
 from ansible.module_utils.junos import junos_argument_spec, check_args
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.netcli import Conditional, FailedConditionalError
 from ansible.module_utils.netconf import send_request
-from ansible.module_utils.network_common import ComplexList, to_list
 from ansible.module_utils.six import string_types, iteritems
 
+try:
+    from lxml.etree import Element, SubElement, tostring
+except ImportError:
+    from xml.etree.ElementTree import Element, SubElement, tostring
+
 try:
     import jxmlease
     HAS_JXMLEASE = True
@@ -182,6 +186,7 @@ except ImportError:
 
 USE_PERSISTENT_CONNECTION = True
 
+
 def to_lines(stdout):
     lines = list()
     for item in stdout:
@@ -190,6 +195,7 @@ def to_lines(stdout):
         lines.append(item)
     return lines
 
+
 def rpc(module, items):
 
     responses = list()
@@ -238,6 +244,7 @@ def rpc(module, items):
 
     return responses
 
+
 def split(value):
     lex = shlex.shlex(value)
     lex.quotes = '"'
@@ -245,6 +252,7 @@ def split(value):
     lex.commenters = ''
     return list(lex)
 
+
 def parse_rpcs(module):
     items = list()
 
@@ -270,6 +278,7 @@ def parse_rpcs(module):
 
     return items
 
+
 def parse_commands(module, warnings):
     items = list()
 
@@ -329,7 +338,6 @@ def main():
     items.extend(parse_rpcs(module))
 
     wait_for = module.params['wait_for'] or list()
-    display = module.params['display']
     conditionals = [Conditional(c) for c in wait_for]
 
     retries = module.params['retries']
@@ -344,8 +352,8 @@ def main():
         for item, resp in zip(items, responses):
             if item['xattrs']['format'] == 'xml':
                 if not HAS_JXMLEASE:
-                    module.fail_json(msg='jxmlease is required but does not appear to '
-                        'be installed.  It can be installed using `pip install jxmlease`')
+                    module.fail_json(msg='jxmlease is required but does not appear to be installed. '
+                                         'It can be installed using `pip install jxmlease`')
 
                 try:
                     transformed.append(jxmlease.parse(resp))
@@ -382,9 +390,7 @@ def main():
         'stdout_lines': to_lines(responses)
     }
 
-
     module.exit_json(**result)
 
-
 if __name__ == '__main__':
     main()