internal/server/tls.go

@@ -73,9 +73,9 @@ func MakeTlsConfig(pagesDomain, cachePath string, cache *certificates.Certificat
 				// Note: We do not check err here because err != nil
 				// always implies that cname == "", which does not have
 				// pagesDomain as a suffix.
-				cname, _ = dns.LookupCNAME(info.ServerName)
+				cname, err := dns.LookupCNAME(info.ServerName)
 				if !strings.HasSuffix(cname, pagesDomain) {
-					log.Warnf("Got ServerName for Domain %s that we're not responsible for", info.ServerName)
+					log.Warnf("Got ServerName for Domain %s that we're not responsible for. CNAME '%s', err: %v", info.ServerName, cname, err)
 					return cache.FallbackCertificate.TlsCertificate, nil
 				}
 			}