dnstxt lookup - add option to return empty list. (#5457)

changelogs/fragments/5457-dnstxt-empty.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - dnstxt lookup plugin - add option to return empty result without empty strings, and return empty list instead of ``NXDOMAIN`` (https://github.com/ansible-collections/community.general/pull/5457, https://github.com/ansible-collections/community.general/issues/5428).

plugins/lookup/dnstxt.py

@@ -20,6 +20,13 @@ DOCUMENTATION = '''
         required: true
         type: list
         elements: string
+      real_empty:
+        description:
+          - Return empty result without empty strings, and return empty list instead of C(NXDOMAIN).
+          - The default for this option will likely change to C(true) in the future.
+        default: false
+        type: bool
+        version_added: 6.0.0
 '''
 
 EXAMPLES = """
@@ -76,6 +83,8 @@ class LookupModule(LookupBase):
         if HAVE_DNS is False:
             raise AnsibleError("Can't LOOKUP(dnstxt): module dns.resolver is not installed")
 
+        real_empty = self.get_option('real_empty')
+
         ret = []
         for term in terms:
             domain = term.split()[0]
@@ -87,10 +96,16 @@ class LookupModule(LookupBase):
                     string.append(s[1:-1])  # Strip outside quotes on TXT rdata
 
             except dns.resolver.NXDOMAIN:
+                if real_empty:
+                    continue
                 string = 'NXDOMAIN'
             except dns.resolver.Timeout:
+                if real_empty:
+                    continue
                 string = ''
             except dns.resolver.NoAnswer:
+                if real_empty:
+                    continue
                 string = ''
             except DNSException as e:
                 raise AnsibleError("dns.resolver unhandled exception %s" % to_native(e))