Add allowed_ttls support to TtlRestrictionFilter

octodns/processor/restrict.py

@@ -18,9 +18,12 @@ class RestrictionException(ProcessorException):
 
 class TtlRestrictionFilter(BaseProcessor):
     '''
-    Ensure that configured TTLs are between a configured minimum and maximum.
+    Ensure that configured TTLs are between a configured minimum and maximum or
+    in an allowed set of values.
+
     The default minimum is 1 (the behavior of 0 is undefined spec-wise) and the
-    default maximum is 604800 (seven days.)
+    default maximum is 604800 (seven days.) allowed_ttls is only used when
+    explicitly configured and min and max are ignored in that case.
 
     Example usage:
 
@@ -29,6 +32,7 @@ class TtlRestrictionFilter(BaseProcessor):
         class: octodns.processor.restrict.TtlRestrictionFilter
         min_ttl: 60
         max_ttl: 3600
+        # allowed_ttls: [300, 900, 3600]
 
     zones:
       exxampled.com.:
@@ -54,16 +58,21 @@ class TtlRestrictionFilter(BaseProcessor):
 
     SEVEN_DAYS = 60 * 60 * 24 * 7
 
-    def __init__(self, name, min_ttl=1, max_ttl=SEVEN_DAYS):
+    def __init__(self, name, min_ttl=1, max_ttl=SEVEN_DAYS, allowed_ttls=None):
         super().__init__(name)
         self.min_ttl = min_ttl
         self.max_ttl = max_ttl
+        self.allowed_ttls = set(allowed_ttls) if allowed_ttls else None
 
     def process_source_zone(self, zone, *args, **kwargs):
         for record in zone.records:
             if record._octodns.get('lenient'):
                 continue
-            if record.ttl < self.min_ttl:
+            if self.allowed_ttls and record.ttl not in self.allowed_ttls:
+                raise RestrictionException(
+                    f'{record.fqdn} ttl={record.ttl} not an allowed value, allowed_ttls={self.allowed_ttls}'
+                )
+            elif record.ttl < self.min_ttl:
                 raise RestrictionException(
                     f'{record.fqdn} ttl={record.ttl} too low, min_ttl={self.min_ttl}'
                 )