feature: allow to set dnsConfig + set default ndots to prevent unnecessary DNS calls

[rysi3k]

I realized that my CoreDNS is being spammed by DNS calls by BetterStack collector:

coredns-58cb755977-7zqmn [INFO] 10.0.11.208:46193 - 63194 "A IN telemetry.betterstack.com.betterstack-collector.svc.cluster.local. udp 83 false 512" NXDOMAIN qr,aa,rd 176 0.000108706s
coredns-58cb755977-7zqmn [INFO] 10.0.11.208:46193 - 44510 "AAAA IN telemetry.betterstack.com.betterstack-collector.svc.cluster.local. udp 83 false 512" NXDOMAIN qr,aa,rd 176 0.00019583s
coredns-58cb755977-7zqmn [INFO] 10.0.11.208:27522 - 63315 "AAAA IN telemetry.betterstack.com.cluster.local. udp 57 false 512" NXDOMAIN qr,aa,rd 150 0.000090319s
coredns-58cb755977-7zqmn [INFO] 10.0.11.208:27522 - 5717 "A IN telemetry.betterstack.com.cluster.local. udp 57 false 512" NXDOMAIN qr,aa,rd 150 0.000106533s
coredns-58cb755977-fcsqq [INFO] 10.0.11.208:44474 - 29835 "A IN telemetry.betterstack.com.production.oraclevcn.com. udp 68 false 512" NXDOMAIN qr,rd,ra 136 0.001152588s
coredns-58cb755977-fcsqq [INFO] 10.0.11.208:44474 - 52364 "AAAA IN telemetry.betterstack.com.production.oraclevcn.com. udp 68 false 512" NXDOMAIN qr,rd,ra 136 0.001178128s
coredns-58cb755977-7zqmn [INFO] 10.0.11.208:14961 - 39474 "AAAA IN telemetry.betterstack.com.subd5a5312aa.production.oraclevcn.com. udp 81 false 512" NXDOMAIN qr,rd,ra 196 0.000928844s
coredns-58cb755977-7zqmn [INFO] 10.0.11.208:14961 - 45361 "A IN telemetry.betterstack.com.subd5a5312aa.production.oraclevcn.com. udp 81 false 512" NXDOMAIN qr,rd,ra 196 0.000894562s
coredns-58cb755977-fcsqq [INFO] 10.0.10.192:6927 - 15926 "AAAA IN s2320703.eu-fsn-3.betterstackdata.com.cluster.local. udp 69 false 512" NXDOMAIN qr,aa,rd 162 0.000147316s
coredns-58cb755977-fcsqq [INFO] 10.0.10.192:6927 - 7476 "A IN s2320703.eu-fsn-3.betterstackdata.com.cluster.local. udp 69 false 512" NXDOMAIN qr,aa,rd 162 0.000193388s
coredns-58cb755977-z7qhl [INFO] 10.0.10.192:25814 - 59149 "AAAA IN s2320703.eu-fsn-3.betterstackdata.com.production.oraclevcn.com. udp 80 false 512" NXDOMAIN qr,aa,rd,ra 148 0.000054524s
coredns-58cb755977-z7qhl [INFO] 10.0.10.192:25814 - 51727 "A IN s2320703.eu-fsn-3.betterstackdata.com.production.oraclevcn.com. udp 80 false 512" NXDOMAIN qr,aa,rd,ra 148 0.000054924s
coredns-58cb755977-7zqmn [INFO] 10.0.10.192:59446 - 22916 "AAAA IN s2320703.eu-fsn-3.betterstackdata.com.betterstack-collector.svc.cluster.local. udp 95 false 512" NXDOMAIN qr,aa,rd 188 0.000140856s
coredns-58cb755977-7zqmn [INFO] 10.0.10.192:59446 - 33671 "A IN s2320703.eu-fsn-3.betterstackdata.com.betterstack-collector.svc.cluster.local. udp 95 false 512" NXDOMAIN qr,aa,rd 188 0.000160836s
coredns-58cb755977-7zqmn [INFO] 10.0.10.192:18139 - 43679 "AAAA IN s2320703.eu-fsn-3.betterstackdata.com.svc.cluster.local. udp 73 false 512" NXDOMAIN qr,aa,rd 166 0.000066472s
coredns-58cb755977-7zqmn [INFO] 10.0.10.192:18139 - 63390 "A IN s2320703.eu-fsn-3.betterstackdata.com.svc.cluster.local. udp 73 false 512" NXDOMAIN qr,aa,rd 166 0.000096217s
coredns-58cb755977-7zqmn [INFO] 10.0.10.192:29049 - 31843 "A IN s2320703.eu-fsn-3.betterstackdata.com.subd5a5312aa.production.oraclevcn.com. udp 93 false 512" NXDOMAIN qr,rd,ra 208 0.001202813s

So reconfiguration of ndots should help with that.

[paweljw]

Thanks @rysi3k , much appreciated! 🙏