diff --git a/lib/ansible/module_utils/netscaler.py b/lib/ansible/module_utils/netscaler.py
index eaef706ddba..486cfbd9535 100644
--- a/lib/ansible/module_utils/netscaler.py
+++ b/lib/ansible/module_utils/netscaler.py
@@ -30,6 +30,7 @@
 
 import json
 import re
+import sys
 
 from ansible.module_utils.basic import env_fallback
 from ansible.module_utils.six import binary_type, text_type
@@ -57,12 +58,20 @@ class ConfigProxy(object):
 
         self.attribute_values_processed = {}
         for attribute, value in self.attribute_values_dict.items():
+            if value is None:
+                continue
             if attribute in transforms:
                 for transform in self.transforms[attribute]:
                     if transform == 'bool_yes_no':
-                        value = 'YES' if value is True else 'NO'
+                        if value is True:
+                            value = 'YES'
+                        elif value is False:
+                            value = 'NO'
                     elif transform == 'bool_on_off':
-                        value = 'ON' if value is True else 'OFF'
+                        if value is True:
+                            value = 'ON'
+                        elif value is False:
+                            value = 'OFF'
                     elif callable(transform):
                         value = transform(value)
                     else:
@@ -130,7 +139,7 @@ class ConfigProxy(object):
 
             # Compare values
             param_type = self.attribute_values_processed[attribute].__class__
-            if param_type(attribute_value) != self.attribute_values_processed[attribute]:
+            if attribute_value is None or param_type(attribute_value) != self.attribute_values_processed[attribute]:
                 str_tuple = (
                     type(self.attribute_values_processed[attribute]),
                     self.attribute_values_processed[attribute],
@@ -180,6 +189,10 @@ def get_immutables_intersection(config_proxy, keys):
 
 def ensure_feature_is_enabled(client, feature_str):
     enabled_features = client.get_enabled_features()
+
+    if enabled_features is None:
+        enabled_features = []
+
     if feature_str not in enabled_features:
         client.enable_features(feature_str)
         client.save_config()
@@ -257,6 +270,12 @@ def get_ns_version(client):
         return int(m.group(1)), int(m.group(2))
 
 
+def get_ns_hardware(client):
+    from nssrc.com.citrix.netscaler.nitro.resource.config.ns.nshardware import nshardware
+    result = nshardware.get(client)
+    return result
+
+
 def monkey_patch_nitro_api():
 
     from nssrc.com.citrix.netscaler.nitro.resource.base.Json import Json
diff --git a/lib/ansible/modules/network/netscaler/netscaler_ssl_certkey.py b/lib/ansible/modules/network/netscaler/netscaler_ssl_certkey.py
new file mode 100644
index 00000000000..006208ac015
--- /dev/null
+++ b/lib/ansible/modules/network/netscaler/netscaler_ssl_certkey.py
@@ -0,0 +1,370 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+#  Copyright (c) 2017 Citrix Systems
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+ANSIBLE_METADATA = {'status': ['preview'],
+                    'supported_by': 'community',
+                    'metadata_version': '1.0'}
+
+
+DOCUMENTATION = '''
+---
+module: netscaler_ssl_certkey
+short_description: Manage ssl cerificate keys.
+description:
+    - Manage ssl cerificate keys.
+
+version_added: "2.4.0"
+
+author: George Nikolopoulos (@giorgos-nikolopoulos)
+
+options:
+
+    certkey:
+        description:
+            - >-
+                Name for the certificate and private-key pair. Must begin with an ASCII alphanumeric or underscore
+                C(_) character, and must contain only ASCII alphanumeric, underscore C(_), hash C(#), period C(.), space C( ),
+                colon C(:), at C(@), equals C(=), and hyphen C(-) characters. Cannot be changed after the certificate-key
+                pair is created.
+            - "The following requirement applies only to the NetScaler CLI:"
+            - >-
+                If the name includes one or more spaces, enclose the name in double or single quotation marks (for
+                example, "my cert" or 'my cert').
+            - "Minimum length = 1"
+
+    cert:
+        description:
+            - >-
+                Name of and, optionally, path to the X509 certificate file that is used to form the certificate-key
+                pair. The certificate file should be present on the appliance's hard-disk drive or solid-state drive.
+                Storing a certificate in any location other than the default might cause inconsistency in a high
+                availability setup. /nsconfig/ssl/ is the default path.
+            - "Minimum length = 1"
+
+    key:
+        description:
+            - >-
+                Name of and, optionally, path to the private-key file that is used to form the certificate-key pair.
+                The certificate file should be present on the appliance's hard-disk drive or solid-state drive.
+                Storing a certificate in any location other than the default might cause inconsistency in a high
+                availability setup. /nsconfig/ssl/ is the default path.
+            - "Minimum length = 1"
+
+    password:
+        description:
+            - >-
+                Passphrase that was used to encrypt the private-key. Use this option to load encrypted private-keys
+                in PEM format.
+
+    inform:
+        choices:
+            - 'DER'
+            - 'PEM'
+            - 'PFX'
+        description:
+            - >-
+                Input format of the certificate and the private-key files. The three formats supported by the
+                appliance are:
+            - "PEM - Privacy Enhanced Mail"
+            - "DER - Distinguished Encoding Rule"
+            - "PFX - Personal Information Exchange."
+
+    passplain:
+        description:
+            - >-
+                Pass phrase used to encrypt the private-key. Required when adding an encrypted private-key in PEM
+                format.
+            - "Minimum length = 1"
+
+    expirymonitor:
+        choices:
+            - 'enabled'
+            - 'disabled'
+        description:
+            - "Issue an alert when the certificate is about to expire."
+
+    notificationperiod:
+        description:
+            - >-
+                Time, in number of days, before certificate expiration, at which to generate an alert that the
+                certificate is about to expire.
+            - "Minimum value = C(10)"
+            - "Maximum value = C(100)"
+
+
+extends_documentation_fragment: netscaler
+requirements:
+    - nitro python sdk
+'''
+
+EXAMPLES = '''
+
+- name: Setup ssl certkey
+  delegate_to: localhost
+  netscaler_ssl_certkey:
+    nitro_user: nsroot
+    nitro_pass: nsroot
+    nsip: 172.18.0.2
+
+    certkey: certirificate_1
+    cert: server.crt
+    key: server.key
+    expirymonitor: enabled
+    notificationperiod: 30
+    inform: PEM
+    password: False
+    passplain: somesecret
+'''
+
+RETURN = '''
+loglines:
+    description: list of logged messages by the module
+    returned: always
+    type: list
+    sample: "['message 1', 'message 2']"
+
+msg:
+    description: Message detailing the failure reason
+    returned: failure
+    type: string
+    sample: "Action does not exist"
+
+diff:
+    description: List of differences between the actual configured object and the configuration specified in the module
+    returned: failure
+    type: dictionary
+    sample: "{ 'targetlbvserver': 'difference. ours: (str) server1 other: (str) server2' }"
+'''
+
+try:
+    from nssrc.com.citrix.netscaler.nitro.resource.config.ssl.sslcertkey import sslcertkey
+    from nssrc.com.citrix.netscaler.nitro.exception.nitro_exception import nitro_exception
+    PYTHON_SDK_IMPORTED = True
+except ImportError as e:
+    PYTHON_SDK_IMPORTED = False
+
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.netscaler import ConfigProxy, get_nitro_client, netscaler_common_arguments, log, loglines, get_immutables_intersection
+
+
+def key_exists(client, module):
+    log('Checking if key exists')
+    log('certkey is %s' % module.params['certkey'])
+    all_certificates = sslcertkey.get(client)
+    certkeys = [item.certkey for item in all_certificates]
+    if module.params['certkey'] in certkeys:
+        return True
+    else:
+        return False
+
+
+def key_identical(client, module, sslcertkey_proxy):
+    log('Checking if configured key is identical')
+    sslcertkey_list = sslcertkey.get_filtered(client, 'certkey:%s' % module.params['certkey'])
+    diff_dict = sslcertkey_proxy.diff_object(sslcertkey_list[0])
+    if 'password' in diff_dict:
+        del diff_dict['password']
+    if 'passplain' in diff_dict:
+        del diff_dict['passplain']
+    if len(diff_dict) == 0:
+        return True
+    else:
+        return False
+
+
+def diff_list(client, module, sslcertkey_proxy):
+    sslcertkey_list = sslcertkey.get_filtered(client, 'certkey:%s' % module.params['certkey'])
+    return sslcertkey_proxy.diff_object(sslcertkey_list[0])
+
+
+def main():
+
+    module_specific_arguments = dict(
+        certkey=dict(type='str'),
+        cert=dict(type='str'),
+        key=dict(type='str'),
+        password=dict(type='bool'),
+        inform=dict(
+            type='str',
+            choices=[
+                'DER',
+                'PEM',
+                'PFX',
+            ]
+        ),
+        passplain=dict(
+            type='str',
+            no_log=True,
+        ),
+        expirymonitor=dict(
+            type='str',
+            choices=[
+                'enabled',
+                'disabled',
+            ]
+        ),
+        notificationperiod=dict(type='float'),
+    )
+
+    argument_spec = dict()
+
+    argument_spec.update(netscaler_common_arguments)
+
+    argument_spec.update(module_specific_arguments)
+
+    module = AnsibleModule(
+        argument_spec=argument_spec,
+        supports_check_mode=True,
+    )
+    module_result = dict(
+        changed=False,
+        failed=False,
+        loglines=loglines,
+    )
+
+    # Fail the module if imports failed
+    if not PYTHON_SDK_IMPORTED:
+        module.fail_json(msg='Could not load nitro python sdk')
+
+    # Fallthrough to rest of execution
+    client = get_nitro_client(module)
+
+    try:
+        client.login()
+    except nitro_exception as e:
+        msg = "nitro exception during login. errorcode=%s, message=%s" % (str(e.errorcode), e.message)
+        module.fail_json(msg=msg)
+    except Exception as e:
+        if str(type(e)) == "<class 'requests.exceptions.ConnectionError'>":
+            module.fail_json(msg='Connection error %s' % str(e))
+        elif str(type(e)) == "<class 'requests.exceptions.SSLError'>":
+            module.fail_json(msg='SSL Error %s' % str(e))
+        else:
+            module.fail_json(msg='Unexpected error during login %s' % str(e))
+
+    readwrite_attrs = [
+        'certkey',
+        'cert',
+        'key',
+        'password',
+        'inform',
+        'passplain',
+        'expirymonitor',
+        'notificationperiod',
+    ]
+
+    readonly_attrs = [
+        'signaturealg',
+        'certificatetype',
+        'serial',
+        'issuer',
+        'clientcertnotbefore',
+        'clientcertnotafter',
+        'daystoexpiration',
+        'subject',
+        'publickey',
+        'publickeysize',
+        'version',
+        'priority',
+        'status',
+        'passcrypt',
+        'data',
+        'servicename',
+    ]
+
+    immutable_attrs = [
+        'certkey',
+        'cert',
+        'key',
+        'password',
+        'inform',
+        'passplain',
+    ]
+
+    transforms = {
+        'expirymonitor': [lambda v: v.upper()],
+    }
+
+    # Instantiate config proxy
+    sslcertkey_proxy = ConfigProxy(
+        actual=sslcertkey(),
+        client=client,
+        attribute_values_dict=module.params,
+        readwrite_attrs=readwrite_attrs,
+        readonly_attrs=readonly_attrs,
+        immutable_attrs=immutable_attrs,
+        transforms=transforms,
+    )
+
+    try:
+
+        if module.params['state'] == 'present':
+            log('Applying actions for state present')
+            if not key_exists(client, module):
+                if not module.check_mode:
+                    log('Adding certificate key')
+                    sslcertkey_proxy.add()
+                    if module.params['save_config']:
+                        client.save_config()
+                module_result['changed'] = True
+            elif not key_identical(client, module, sslcertkey_proxy):
+
+                # Check if we try to change value of immutable attributes
+                immutables_changed = get_immutables_intersection(sslcertkey_proxy, diff_list(client, module, sslcertkey_proxy).keys())
+                if immutables_changed != []:
+                    module.fail_json(
+                        msg='Cannot update immutable attributes %s' % (immutables_changed,),
+                        diff=diff_list(client, module, sslcertkey_proxy),
+                        **module_result
+                    )
+
+                if not module.check_mode:
+                    sslcertkey_proxy.update()
+                    if module.params['save_config']:
+                        client.save_config()
+                module_result['changed'] = True
+            else:
+                module_result['changed'] = False
+
+            # Sanity check for state
+            if not module.check_mode:
+                log('Sanity checks for state present')
+                if not key_exists(client, module):
+                    module.fail_json(msg='SSL certkey does not exist')
+                if not key_identical(client, module, sslcertkey_proxy):
+                    module.fail_json(msg='SSL certkey differs from configured', diff=diff_list(client, module, sslcertkey_proxy))
+
+        elif module.params['state'] == 'absent':
+            log('Applying actions for state absent')
+            if key_exists(client, module):
+                if not module.check_mode:
+                    sslcertkey_proxy.delete()
+                    if module.params['save_config']:
+                        client.save_config()
+                module_result['changed'] = True
+            else:
+                module_result['changed'] = False
+
+            # Sanity check for state
+            if not module.check_mode:
+                log('Sanity checks for state absent')
+                if key_exists(client, module):
+                    module.fail_json(msg='SSL certkey still exists')
+
+    except nitro_exception as e:
+        msg = "nitro exception errorcode=%s, message=%s" % (str(e.errorcode), e.message)
+        module.fail_json(msg=msg, **module_result)
+
+    client.logout()
+    module.exit_json(**module_result)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/test/integration/roles/netscaler_ssl_certkey/defaults/main.yaml b/test/integration/roles/netscaler_ssl_certkey/defaults/main.yaml
new file mode 100644
index 00000000000..641801f6600
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/defaults/main.yaml
@@ -0,0 +1,6 @@
+---
+testcase: "*"
+test_cases: []
+
+nitro_user: nsroot
+nitro_pass: nsroot
diff --git a/test/integration/roles/netscaler_ssl_certkey/sample_inventory b/test/integration/roles/netscaler_ssl_certkey/sample_inventory
new file mode 100644
index 00000000000..42635796914
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/sample_inventory
@@ -0,0 +1,5 @@
+
+
+[netscaler]
+
+netscaler01 nsip=172.18.0.2 nitro_user=nsroot nitro_pass=nsroot
diff --git a/test/integration/roles/netscaler_ssl_certkey/tasks/main.yaml b/test/integration/roles/netscaler_ssl_certkey/tasks/main.yaml
new file mode 100644
index 00000000000..84af8dca9e9
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/tasks/main.yaml
@@ -0,0 +1,3 @@
+---
+
+- { include: nitro.yaml, tags: ['nitro'] }
diff --git a/test/integration/roles/netscaler_ssl_certkey/tasks/nitro.yaml b/test/integration/roles/netscaler_ssl_certkey/tasks/nitro.yaml
new file mode 100644
index 00000000000..00ab502dda9
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/tasks/nitro.yaml
@@ -0,0 +1,14 @@
+- name: collect all nitro test cases
+  find:
+    paths: "{{ role_path }}/tests/nitro"
+    patterns: "{{ testcase }}.yaml"
+  register: test_cases
+
+- name: set test_items
+  set_fact: test_items="{{ test_cases.files | map(attribute='path') | list }}"
+
+- name: run test case
+  include: "{{ test_case_to_run }}"
+  with_items: "{{ test_items }}"
+  loop_control:
+    loop_var: test_case_to_run
diff --git a/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey.yaml b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey.yaml
new file mode 100644
index 00000000000..cda63836438
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey.yaml
@@ -0,0 +1,57 @@
+---
+
+- include: "{{ role_path }}/tests/nitro/certkey/setup.yaml"
+  vars:
+    check_mode: yes
+
+- assert:
+    that: result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/setup.yaml"
+  vars:
+    check_mode: no
+
+- assert:
+    that: result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/setup.yaml"
+  vars:
+    check_mode: yes
+
+- assert:
+    that: not result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/setup.yaml"
+  vars:
+    check_mode: no
+
+- assert:
+    that: not result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/remove.yaml"
+  vars:
+    check_mode: yes
+
+- assert:
+    that: result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/remove.yaml"
+  vars:
+    check_mode: no
+
+- assert:
+    that: result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/remove.yaml"
+  vars:
+    check_mode: yes
+
+- assert:
+    that: not result|changed
+
+- include: "{{ role_path }}/tests/nitro/certkey/remove.yaml"
+  vars:
+    check_mode: no
+
+- assert:
+    that: not result|changed
diff --git a/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/remove.yaml b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/remove.yaml
new file mode 100644
index 00000000000..9224a6ad7dc
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/remove.yaml
@@ -0,0 +1,13 @@
+---
+
+- name: Setup cs action
+  delegate_to: localhost
+  register: result
+  check_mode: "{{ check_mode }}"
+  netscaler_ssl_certkey:
+    nitro_user: "{{nitro_user}}"
+    nitro_pass: "{{nitro_pass}}"
+    nsip: "{{nsip}}"
+
+    state: absent
+    certkey: certirificate_1
diff --git a/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/setup.yaml b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/setup.yaml
new file mode 100644
index 00000000000..1a0a00e2ac0
--- /dev/null
+++ b/test/integration/roles/netscaler_ssl_certkey/tests/nitro/certkey/setup.yaml
@@ -0,0 +1,22 @@
+---
+
+
+- name: Setup cs action
+  delegate_to: localhost
+  register: result
+  check_mode: "{{ check_mode }}"
+  netscaler_ssl_certkey:
+    nitro_user: "{{nitro_user}}"
+    nitro_pass: "{{nitro_pass}}"
+    nsip: "{{nsip}}"
+
+    state: present
+
+    certkey: certirificate_1
+    cert: server.crt
+    key: server.key
+    expirymonitor: enabled
+    notificationperiod: 30
+    inform: PEM
+    password: False
+    passplain: somesecret
diff --git a/test/units/modules/network/netscaler/test_netscaler_ssl_certkey.py b/test/units/modules/network/netscaler/test_netscaler_ssl_certkey.py
new file mode 100644
index 00000000000..311a15aa81f
--- /dev/null
+++ b/test/units/modules/network/netscaler/test_netscaler_ssl_certkey.py
@@ -0,0 +1,618 @@
+
+#  Copyright (c) 2017 Citrix Systems
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+from ansible.compat.tests.mock import patch, Mock, MagicMock, call
+from .netscaler_module import TestModule, nitro_base_patcher, set_module_args
+
+import sys
+
+if sys.version_info[:2] != (2, 6):
+    import requests
+
+
+class TestNetscalerSSLCertkeyModule(TestModule):
+
+    @classmethod
+    def setUpClass(cls):
+        class MockException(Exception):
+            pass
+
+        cls.MockException = MockException
+
+        m = MagicMock()
+        cls.server_mock = MagicMock()
+        cls.server_mock.__class__ = MagicMock(add=Mock())
+        nssrc_modules_mock = {
+            'nssrc.com.citrix.netscaler.nitro.resource.config.ssl': m,
+            'nssrc.com.citrix.netscaler.nitro.resource.config.ssl.sslcertkey': m,
+            'nssrc.com.citrix.netscaler.nitro.resource.config.ssl.sslcertkey.sslcertkey': m,
+        }
+
+        cls.nitro_specific_patcher = patch.dict(sys.modules, nssrc_modules_mock)
+        cls.nitro_base_patcher = nitro_base_patcher
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.nitro_base_patcher.stop()
+        cls.nitro_specific_patcher.stop()
+
+    def setUp(self):
+        self.nitro_base_patcher.start()
+        self.nitro_specific_patcher.start()
+
+        # Setup minimal required arguments to pass AnsibleModule argument parsing
+
+    def tearDown(self):
+        self.nitro_base_patcher.stop()
+        self.nitro_specific_patcher.stop()
+
+    def test_graceful_nitro_api_import_error(self):
+        # Stop nitro api patching to cause ImportError
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        self.nitro_base_patcher.stop()
+        self.nitro_specific_patcher.stop()
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+        self.module = netscaler_ssl_certkey
+        result = self.failed()
+        self.assertEqual(result['msg'], 'Could not load nitro python sdk')
+
+    def test_graceful_nitro_error_on_login(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        class MockException(Exception):
+            def __init__(self, *args, **kwargs):
+                self.errorcode = 0
+                self.message = ''
+
+        client_mock = Mock()
+        client_mock.login = Mock(side_effect=MockException)
+        m = Mock(return_value=client_mock)
+        with patch('ansible.modules.network.netscaler.netscaler_ssl_certkey.get_nitro_client', m):
+            with patch('ansible.modules.network.netscaler.netscaler_ssl_certkey.nitro_exception', MockException):
+                self.module = netscaler_ssl_certkey
+                result = self.failed()
+                self.assertTrue(result['msg'].startswith('nitro exception'), msg='nitro exception during login not handled properly')
+
+    def test_graceful_no_connection_error(self):
+
+        if sys.version_info[:2] == (2, 6):
+            self.skipTest('requests library not available under python2.6')
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        class MockException(Exception):
+            pass
+        client_mock = Mock()
+        attrs = {'login.side_effect': requests.exceptions.ConnectionError}
+        client_mock.configure_mock(**attrs)
+        m = Mock(return_value=client_mock)
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            nitro_exception=MockException,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertTrue(result['msg'].startswith('Connection error'), msg='Connection error was not handled gracefully')
+
+    def test_graceful_login_error(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        if sys.version_info[:2] == (2, 6):
+            self.skipTest('requests library not available under python2.6')
+
+        class MockException(Exception):
+            pass
+        client_mock = Mock()
+        attrs = {'login.side_effect': requests.exceptions.SSLError}
+        client_mock.configure_mock(**attrs)
+        m = Mock(return_value=client_mock)
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            nitro_exception=MockException,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertTrue(result['msg'].startswith('SSL Error'), msg='SSL Error was not handled gracefully')
+
+    def test_save_config_called_on_state_present(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_mock = Mock()
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            key_exists=Mock(side_effect=[False, True]),
+            key_identical=Mock(side_effect=[True]),
+            ConfigProxy=Mock(return_value=ssl_certkey_proxy_mock),
+            nitro_exception=self.MockException,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            self.assertIn(call.save_config(), client_mock.mock_calls)
+
+    def test_save_config_called_on_state_absent(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_mock = Mock()
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            key_exists=Mock(side_effect=[True, False]),
+            ConfigProxy=Mock(return_value=ssl_certkey_proxy_mock),
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            self.assertIn(call.save_config(), client_mock.mock_calls)
+
+    def test_save_config_not_called_on_state_present(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+            save_config=False,
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_mock = Mock()
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            key_exists=Mock(side_effect=[False, True]),
+            key_identical=Mock(side_effect=[True]),
+            ConfigProxy=Mock(return_value=ssl_certkey_proxy_mock),
+            nitro_exception=self.MockException,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            self.assertNotIn(call.save_config(), client_mock.mock_calls)
+
+    def test_save_config_not_called_on_state_absent(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+            save_config=False,
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_mock = Mock()
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            key_exists=Mock(side_effect=[True, False]),
+            ConfigProxy=Mock(return_value=ssl_certkey_proxy_mock),
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            self.assertNotIn(call.save_config(), client_mock.mock_calls)
+
+    def test_new_ssl_certkey_execution_flow(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            key_exists=Mock(side_effect=[False, True]),
+            key_identical=Mock(side_effect=[True]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            ssl_certkey_proxy_mock.assert_has_calls([call.add()])
+
+    def test_modified_server_execution_flow(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[True, True]),
+            key_identical=Mock(side_effect=[False, True]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            ssl_certkey_proxy_mock.assert_has_calls([call.update()])
+
+    def test_absent_server_execution_flow(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[True, False]),
+            key_identical=Mock(side_effect=[False, True]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            ssl_certkey_proxy_mock.assert_has_calls([call.delete()])
+
+    def test_present_key_identical_flow(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[True, True]),
+            key_identical=Mock(side_effect=[True, True]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            ssl_certkey_proxy_mock.assert_not_called()
+
+    def test_absent_server_noop_flow(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[False, False]),
+            key_identical=Mock(side_effect=[False, False]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            self.exited()
+            ssl_certkey_proxy_mock.assert_not_called()
+
+    def test_present_server_failed_update(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            nitro_exception=self.MockException,
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[True, True]),
+            key_identical=Mock(side_effect=[False, False]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertEqual(result['msg'], 'SSL certkey differs from configured')
+            self.assertTrue(result['failed'])
+
+    def test_present_server_failed_create(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            nitro_exception=self.MockException,
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[False, False]),
+            key_identical=Mock(side_effect=[False, False]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertEqual(result['msg'], 'SSL certkey does not exist')
+            self.assertTrue(result['failed'])
+
+    def test_present_server_update_immutable_attribute(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            nitro_exception=self.MockException,
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=['domain']),
+            key_exists=Mock(side_effect=[True, True]),
+            key_identical=Mock(side_effect=[False, False]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertEqual(result['msg'], 'Cannot update immutable attributes [\'domain\']')
+            self.assertTrue(result['failed'])
+
+    def test_absent_server_failed_delete(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        client_mock = Mock()
+
+        m = Mock(return_value=client_mock)
+
+        ssl_certkey_proxy_attrs = {
+            'diff_object.return_value': {},
+        }
+        ssl_certkey_proxy_mock = Mock()
+        ssl_certkey_proxy_mock.configure_mock(**ssl_certkey_proxy_attrs)
+        config_proxy_mock = Mock(return_value=ssl_certkey_proxy_mock)
+
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            nitro_exception=self.MockException,
+            get_nitro_client=m,
+            diff_list=Mock(return_value={}),
+            get_immutables_intersection=Mock(return_value=[]),
+            key_exists=Mock(side_effect=[True, True]),
+            key_identical=Mock(side_effect=[False, False]),
+            ConfigProxy=config_proxy_mock,
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertEqual(result['msg'], 'SSL certkey still exists')
+            self.assertTrue(result['failed'])
+
+    def test_graceful_nitro_exception_state_present(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='present',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        class MockException(Exception):
+            def __init__(self, *args, **kwargs):
+                self.errorcode = 0
+                self.message = ''
+
+        m = Mock(side_effect=MockException)
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            key_exists=m,
+            nitro_exception=MockException
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertTrue(
+                result['msg'].startswith('nitro exception'),
+                msg='Nitro exception not caught on operation absent'
+            )
+
+    def test_graceful_nitro_exception_state_absent(self):
+        set_module_args(dict(
+            nitro_user='user',
+            nitro_pass='pass',
+            nsip='1.1.1.1',
+            state='absent',
+        ))
+        from ansible.modules.network.netscaler import netscaler_ssl_certkey
+
+        class MockException(Exception):
+            def __init__(self, *args, **kwargs):
+                self.errorcode = 0
+                self.message = ''
+
+        m = Mock(side_effect=MockException)
+        with patch.multiple(
+            'ansible.modules.network.netscaler.netscaler_ssl_certkey',
+            key_exists=m,
+            nitro_exception=MockException
+        ):
+            self.module = netscaler_ssl_certkey
+            result = self.failed()
+            self.assertTrue(
+                result['msg'].startswith('nitro exception'),
+                msg='Nitro exception not caught on operation absent'
+            )