Added check for avi SDK version as suggested in review. (#21927)

* Added check for avi SDK version as suggested in review.

* Fixed documentation based on review.

* Renamed module_utils.avi to module_utils.avi_ansible_utils
as import of avi.sdk would fail due to name collisions.

Moved the code to check for AVI version into the ansible modules.

* Updated the module with note about reason for name change.

lib/ansible/module_utils/avi_ansible_utils.py

@@ -0,0 +1,83 @@
+# This code is part of Ansible, but is an independent component.
+# This particular file snippet, and this file snippet only, is BSD licensed.
+# Modules you write using this snippet, which is embedded dynamically by Ansible
+# still belong to the author of the module, and may assign their own license
+# to the complete work.
+#
+# Copyright (c), Gaurav Rastogi <grastogi@avinetworks.com>, 2017
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+#    * Redistributions of source code must retain the above copyright
+#      notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above copyright notice,
+#      this list of conditions and the following disclaimer in the documentation
+#      and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+# This module initially matched the namespace of network module avi. However,
+# that causes namespace import error when other modules from avi namespaces
+# are imported. In order to avoid the import collisions this was renamed to
+# avi_ansible_utils to allow this module to be ceterpiece of all integration
+# with external avi modules.
+
+import os
+from pkg_resources import parse_version
+
+HAS_AVI = True
+try:
+    import avi.sdk
+    sdk_version = getattr(avi.sdk, '__version__', None)
+    if ((sdk_version is None) or (sdk_version and
+            (parse_version(sdk_version) < parse_version('16.3.5.post1')))):
+        # It allows the __version__ to be '' as that value is used in development builds
+        raise ImportError
+    from avi.sdk.utils.ansible_utils import avi_ansible_api
+except ImportError:
+    HAS_AVI = False
+
+
+def avi_common_argument_spec():
+    """
+    Returns common arguments for all Avi modules
+    :return: dict
+    """
+    return dict(
+        controller=dict(default=os.environ.get('AVI_CONTROLLER', '')),
+        username=dict(default=os.environ.get('AVI_USERNAME', '')),
+        password=dict(default=os.environ.get('AVI_PASSWORD', ''), no_log=True),
+        tenant=dict(default='admin'),
+        tenant_uuid=dict(default=''))
+
+
+def ansible_return(module, rsp, changed, req=None, existing_obj=None):
+    """
+    Helper function to return the right ansible return based on the error code and
+    changed status.
+    :param module: AnsibleModule
+    :param rsp: ApiResponse object returned from ApiSession.
+    :param changed: Whether something changed in this module.
+    :param req: Dict data for Avi API call.
+    :param existing_obj: Dict representing current HTTP resource in Avi Controller.
+
+    Returns: specific ansible module exit function
+    """
+    if rsp.status_code > 299:
+        return module.fail_json(msg='Error %d Msg %s req: %s' % (
+            rsp.status_code, rsp.text, req))
+    if changed and existing_obj:
+        return module.exit_json(
+            changed=changed, obj=rsp.json(), old_obj=existing_obj)
+    return module.exit_json(changed=changed, obj=rsp.json())