Report dns query status

urlchecker_dns.py

 import dns
 from urlchecker_network import logNetwork
+from peewee import fn
 
 URL_TO_CHECK = "example.org"
 TIMEOUT = 2
 
 
+def reportDnsQuery(db, resolver_ip=None, domain=None, rdtype=None):
+    # http://charlesleifer.com/blog/techniques-for-querying-lists-of-objects-and-determining-the-top-related-item/
+    DnsChangeAlias = db.DnsChange.alias()
+
+    subquery = (
+        DnsChangeAlias.select(
+            DnsChangeAlias.resolver_ip,
+            DnsChangeAlias.domain,
+            DnsChangeAlias.rdtype,
+            fn.MAX(DnsChangeAlias.status_id).alias("max_status_id"),
+        )
+        .group_by(
+            DnsChangeAlias.resolver_ip,
+            DnsChangeAlias.domain,
+            DnsChangeAlias.rdtype,
+        )
+        .alias("dns_change_max_subquery")
+    )
+
+    StatusAlias = db.Status.alias()
+
+    query = (
+        db.DnsChange.select(db.DnsChange, StatusAlias)
+        .join(StatusAlias)
+        .switch(db.DnsChange)
+        .join(
+            subquery,
+            on=(
+                (db.DnsChange.status_id == subquery.c.max_status_id)
+                & (db.DnsChange.resolver_ip == subquery.c.resolver_ip)
+                & (db.DnsChange.domain == subquery.c.domain)
+                & (db.DnsChange.rdtype == subquery.c.rdtype)
+            ),
+        )
+        .order_by(
+            db.DnsChange.domain.asc(),
+            db.DnsChange.rdtype.asc(),
+            db.DnsChange.resolver_ip.asc(),
+        )
+    )
+
+    if resolver_ip is not None:
+        if type(resolver_ip) == list:
+            query = query.where(db.DnsChange.resolver_ip << resolver_ip)
+        else:
+            query = query.where(db.DnsChange.resolver_ip == resolver_ip)
+    if domain is not None:
+        if type(domain) == list:
+            query = query.where(db.DnsChange.domain << domain)
+        else:
+            query = query.where(db.DnsChange.domain == domain)
+    if rdtype is not None:
+        if type(rdtype) == list:
+            query = query.where(db.DnsChange.rdtype << rdtype)
+        else:
+            query = query.where(db.DnsChange.rdtype == rdtype)
+    return query
+
+
 def logDnsQuery(db, status_id, resolver_ip, domain_text, rdtype, answer_list):
     answer_list.sort()
     response = ", ".join(answer_list)
@@ -12,16 +72,9 @@ def logDnsQuery(db, status_id, resolver_ip, domain_text, rdtype, answer_list):
     with db._db.atomic():
         try:
             # Check previous parameter value
-            previous_entry = (
-                db.DnsChange.select()
-                .where(
-                    db.DnsChange.resolver_ip == resolver_ip,
-                    db.DnsChange.domain == domain_text,
-                    db.DnsChange.rdtype == rdtype,
-                )
-                .order_by(db.DnsChange.status.desc())
-                .get()
-            )
+            previous_entry = reportDnsQuery(
+                db, resolver_ip=resolver_ip, domain=domain_text, rdtype=rdtype
+            ).get()
         except db.DnsChange.DoesNotExist:
             previous_entry = None