GH-3798: Wrap DNS request validation in a retry

agent/dns_test.go

@@ -1925,7 +1925,7 @@ func TestDNS_PreparedQueryNearIP(t *testing.T) {
 		err := a.RPC("PreparedQuery.Apply", args, &id)
 		require.NoError(t, err)
 	}
-	
+	retry.Run(t, func(r *retry.R) {
 		m :=new(dns.Msg)
 		m.SetQuestion("some.query.we.like.query.consul.", dns.TypeA)
 		m.SetEdns0(4096, false)
@@ -1943,16 +1943,24 @@ func TestDNS_PreparedQueryNearIP(t *testing.T) {
 		
 		c := new(dns.Client)
 		in, _, err := c.Exchange(m, a.DNSAddr())
-	require.NoErrorf(t, err, "Error with call to dns.Client.Exchange: %s", err)
+		if err != nil {
+			r.Fatalf("Error with call to dns.Client.Exchange: %s", err)
+		}
 		
-	require.Equalf(t, len(serviceNodes), len(in.Answer), "Expecting %d A RRs in response, Actual found was %d", len(serviceNodes), len(in.Answer))
+		if len(serviceNodes) != len(in.Answer) {
+			r.Fatalf("Expecting %d A RRs in response, Actual found was %d", len(serviceNodes), len(in.Answer))
+		}
 		
 		for i, rr := range in.Answer {
-		aRec, ok := rr.(*dns.A);
+			if aRec, ok := rr.(*dns.A); ok {
-		require.Truef(t, ok, "DNS Answer contained a non A RR")
+				if actual := aRec.A.String(); serviceNodes[i].address != actual {
-		actual := aRec.A.String()
+					r.Fatalf("Expecting A RR #%d = %s, Actual RR was %s", i, serviceNodes[i].address, actual)
-		require.Equalf(t, serviceNodes[i].address, actual, "Expecting A RR #%d = %s, Actual RR was %s", i, serviceNodes[i].address, actual)
+				}
+			} else {
+				r.Fatalf("DNS Answer container a non-A RR")
 			}
+		}
+	})
 }
 
 func TestDNS_ServiceLookup_PreparedQueryNamePeriod(t *testing.T) {