nxos_snmp_user: platform fixes for get_snmp_user (#55832)

* nxos_snmp_user: platform fixes for get_snmp_user

snmp user output behavior varies quite a bit for the different nxos platforms and required several workarounds:

- N5K/N6k
 - These platforms do not support structured output for `show snmp user`.
 - The current code lands in an `except` clause when the output is not structured; so I added a new `get_non_structured_snmp_user` method to scrape the state from the regular cli output if it's present.

- N9K-F
 - The `group` data in the JSON output is different for this platform; it has a different key (just `group` instead of `TABLE_groups` or `group_names`) and it is not indexed
 - For a single group the value is a string, for multiple groups it's a list

- sanity
 - N5K/N6K/N9K-F platforms will reject `no snmp user <name> <role>` when it's the last role defined for the user.
 - workaround is to use `nxos_user` to remove the user

- Changes validated on:
 - `N3K, N3K-F, N35, N6K, N7K, N9K, N9K-F`
 - `6.0(2)A8`
 - `7.0(3)I2, 7.0(3)I4, 7.0(3)I5, 7.0(3)I6, 7.0(3)I7`
 - `7.3(2)D1`
 - `7.3(3)N1, 7.3(4)N1`
 - `8.3(2)`
 - `9.2(2), 9.2(3)`

* fix lint warning

lib/ansible/modules/network/nxos/nxos_snmp_user.py

@@ -90,6 +90,7 @@ commands:
     sample: ["snmp-server user ntc network-operator auth md5 test_password"]
 '''
 
+import re
 
 from ansible.module_utils.network.nxos.nxos import load_config, run_commands
 from ansible.module_utils.network.nxos.nxos import nxos_argument_spec, check_args
@@ -134,6 +135,7 @@ def get_snmp_groups(module):
 def get_snmp_user(user, module):
     command = 'show snmp user {0}'.format(user)
     body = execute_show_command(command, module, text=True)
+    body_text = body[0]
 
     if 'No such entry' not in body[0]:
         body = execute_show_command(command, module)
@@ -177,9 +179,9 @@ def get_snmp_user(user, module):
         else:
             resource['encrypt'] = 'none'
 
-        group_table = resource_table[tablegrpkey][rowgrpkey]
-
         groups = []
+        if tablegrpkey in resource_table:
+            group_table = resource_table[tablegrpkey][rowgrpkey]
             try:
                 for group in group_table:
                     groups.append(str(group[grpkey]).strip())
@@ -195,11 +197,57 @@ def get_snmp_user(user, module):
                 for each in rt:
                     groups.append(each['user'].strip())
 
+        # Some 'F' platforms use 'group' key instead
+        elif 'group' in resource_table:
+            # single group is a string, multiple groups in a list
+            groups = resource_table['group']
+            if isinstance(groups, str):
+                groups = [groups]
+
         resource['group'] = groups
 
     except (KeyError, AttributeError, IndexError, TypeError):
+        if not resource and body_text and 'No such entry' not in body_text:
+            # 6K and other platforms may not return structured output;
+            # attempt to get state from text output
+            resource = get_non_structured_snmp_user(body_text)
+
     return resource
 
+
+def get_non_structured_snmp_user(body_text):
+    # This method is a workaround for platforms that don't support structured
+    # output for 'show snmp user <foo>'. This workaround may not work on all
+    # platforms. Sample non-struct output:
+    #
+    # User                Auth  Priv(enforce) Groups              acl_filter
+    # ____                ____  _____________ ______              __________
+    # sample1             no    no            network-admin       ipv4:my_acl
+    #                                         network-operator
+    #                                         priv-11
+    #         -OR-
+    # sample2             md5   des(no)       priv-15
+    #         -OR-
+    # sample3             md5   aes-128(no)   network-admin
+    resource = {}
+    output = body_text.rsplit('__________')[-1]
+    pat = re.compile(r'^(?P<user>\S+)\s+'
+                     r'(?P<auth>\S+)\s+'
+                     r'(?P<priv>[\w\d-]+)(?P<enforce>\([\w\d-]+\))*\s+'
+                     r'(?P<group>\S+)',
+                     re.M)
+    m = re.search(pat, output)
+    if not m:
+        return resource
+    resource['user'] = m.group('user')
+    resource['auth'] = m.group('auth')
+    resource['encrypt'] = 'aes-128' if 'aes' in str(m.group('priv')) else 'none'
+
+    resource['group'] = [m.group('group')]
+    more_groups = re.findall(r'^\s+([\w\d-]+)\s*$', output, re.M)
+    if more_groups:
+        resource['group'] += more_groups
+
     return resource
 
 

test/integration/targets/nxos_snmp_user/tests/common/sanity.yaml

@@ -4,10 +4,21 @@
   when: ansible_connection == "local"
 
 - name: Remove snmp user
-  nxos_snmp_user: &remove
+  nxos_snmp_user: &remove_snmp_user
     user: ntc
     provider: "{{ connection }}"
     state: absent
+  ignore_errors: yes
+  when: platform is not search('N5K|N6K|N9K-F')
+
+- name: Remove user workaround
+  # Some platforms will not allow snmp_user to remove the last role
+  nxos_user: &workaround_remove_user
+    name: ntc
+    provider: "{{ connection }}"
+    state: absent
+  ignore_errors: yes
+  when: platform is search('N5K|N6K|N9K-F')
 
 - pause:
     seconds: 5
@@ -64,6 +75,8 @@
 
   - assert: *false
 
+  - block:
+    # Some platforms will not allow snmp_user to remove the last role
     - name: delete snmp user
       nxos_snmp_user: &remove1
         user: ntc
@@ -82,9 +95,15 @@
       register: result
 
     - assert: *false
+    when: platform is not search('N5K|N6K|N9K-F')
 
   always:
     - name: delete snmp user
-      nxos_snmp_user: *remove
+      nxos_snmp_user: *remove_snmp_user
+      when: platform is not search('N5K|N6K|N9K-F')
+
+    - name: remove user workaround
+      nxos_user: *workaround_remove_user
+      when: platform is search('N5K|N6K|N9K-F')
 
 - debug: msg="END connection={{ ansible_connection }} nxos_snmp_user sanity test"