Pluribus Networks dhcp filter module with unit tests (#49848)

* Pluribus Networks dhcp filter module with unit tests
* Added type which was missing in doc
* Removed unwanted global variable
* Fix return type

lib/ansible/modules/network/netvisor/pn_dhcp_filter.py

@@ -0,0 +1,174 @@
+#!/usr/bin/python
+# Copyright: (c) 2018, Pluribus Networks
+# 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 = {'metadata_version': '1.1',
+                    'status': ['preview'],
+                    'supported_by': 'community'}
+
+
+DOCUMENTATION = """
+---
+module: pn_dhcp_filter
+author: "Pluribus Networks (@rajaspachipulusu17)"
+version_added: "2.8"
+short_description: CLI command to create/modify/delete dhcp-filter
+description:
+  - This module can be used to create, delete and modify a DHCP filter config.
+options:
+  pn_cliswitch:
+    description:
+      - Target switch to run the CLI on.
+    required: False
+    type: str
+  state:
+    description:
+      - State the action to perform. Use C(present) to create dhcp-filter and
+        C(absent) to delete dhcp-filter C(update) to modify the dhcp-filter.
+    required: True
+    type: str
+    choices: ['present', 'absent', 'update']
+  pn_trusted_ports:
+    description:
+      - trusted ports of dhcp config.
+    required: False
+    type: str
+  pn_name:
+    description:
+      - name of the DHCP filter.
+    required: false
+    type: str
+"""
+
+EXAMPLES = """
+- name: dhcp filter create
+  pn_dhcp_filter:
+    pn_cliswitch: "sw01"
+    pn_name: "foo"
+    state: "present"
+    pn_trusted_ports: "1"
+
+- name: dhcp filter delete
+  pn_dhcp_filter:
+    pn_cliswitch: "sw01"
+    pn_name: "foo"
+    state: "absent"
+    pn_trusted_ports: "1"
+
+- name: dhcp filter modify
+  pn_dhcp_filter:
+    pn_cliswitch: "sw01"
+    pn_name: "foo"
+    state: "update"
+    pn_trusted_ports: "1,2"
+"""
+
+RETURN = """
+command:
+  description: the CLI command run on the target node.
+  returned: always
+  type: str
+stdout:
+  description: set of responses from the dhcp-filter command.
+  returned: always
+  type: list
+stderr:
+  description: set of error responses from the dhcp-filter command.
+  returned: on error
+  type: list
+changed:
+  description: indicates whether the CLI caused changes on the target.
+  returned: always
+  type: bool
+"""
+
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.network.netvisor.pn_nvos import pn_cli, run_cli
+
+
+def check_cli(module, cli):
+    """
+    This method checks for idempotency using the dhcp-filter-show command.
+    If a user with given name exists, return True else False.
+    :param module: The Ansible module to fetch input parameters
+    :param cli: The CLI string
+    """
+    user_name = module.params['pn_name']
+
+    cli += ' dhcp-filter-show format name no-show-headers'
+    out = module.run_command(cli.split(), use_unsafe_shell=True)[1]
+
+    out = out.split()
+
+    return True if user_name in out else False
+
+
+def main():
+    """ This section is for arguments parsing """
+
+    state_map = dict(
+        present='dhcp-filter-create',
+        absent='dhcp-filter-delete',
+        update='dhcp-filter-modify'
+    )
+
+    module = AnsibleModule(
+        argument_spec=dict(
+            pn_cliswitch=dict(required=False, type='str'),
+            state=dict(required=True, type='str',
+                       choices=state_map.keys()),
+            pn_trusted_ports=dict(required=False, type='str'),
+            pn_name=dict(required=False, type='str'),
+        ),
+        required_if=[
+            ["state", "present", ["pn_name", "pn_trusted_ports"]],
+            ["state", "absent", ["pn_name"]],
+            ["state", "update", ["pn_name", "pn_trusted_ports"]]
+        ]
+    )
+
+    # Accessing the arguments
+    cliswitch = module.params['pn_cliswitch']
+    state = module.params['state']
+    trusted_ports = module.params['pn_trusted_ports']
+    name = module.params['pn_name']
+
+    command = state_map[state]
+
+    # Building the CLI command string
+    cli = pn_cli(module, cliswitch)
+
+    USER_EXISTS = check_cli(module, cli)
+    cli += ' %s name %s ' % (command, name)
+
+    if command == 'dhcp-filter-modify':
+        if USER_EXISTS is False:
+            module.fail_json(
+                failed=True,
+                msg='dhcp-filter with name %s does not exist' % name
+            )
+    if command == 'dhcp-filter-delete':
+        if USER_EXISTS is False:
+            module.exit_json(
+                skipped=True,
+                msg='dhcp-filter with name %s does not exist' % name
+            )
+    if command == 'dhcp-filter-create':
+        if USER_EXISTS is True:
+            module.exit_json(
+                skipped=True,
+                msg='dhcp-filter with name %s already exists' % name
+            )
+    if command != 'dhcp-filter-delete':
+        if trusted_ports:
+            cli += ' trusted-ports ' + trusted_ports
+
+    run_cli(module, cli, state_map)
+
+
+if __name__ == '__main__':
+    main()