CIDR query routing (#1159)

* core: allow all CIDR ranges in zone specifications

Allow (e.g.) a v4 reverse on a /17. If a zone is specified in such a
way a FilterFunc is set in the config. This filter is checked against
incoming queries.

For all other queries this adds a 'x != nil' check which will not impact
performace too much. Benchmark function is added as well to check for
this as wel.

Add multiple tests in tests/server_reverse_test.go.

Benchmark shows in the non-reverse case this hardly impact the speed:

~~~
classless:
pkg: github.com/coredns/coredns/core/dnsserver
BenchmarkCoreServeDNS-4   	 1000000	      1431 ns/op	      16 B/op	       1 allocs/op

pkg: github.com/coredns/coredns/core/dnsserver
BenchmarkCoreServeDNS-4   	 1000000	      1429 ns/op	      16 B/op	       1 allocs/op

master:
pkg: github.com/coredns/coredns/core/dnsserver
BenchmarkCoreServeDNS-4   	 1000000	      1412 ns/op	      16 B/op	       1 allocs/op

pkg: github.com/coredns/coredns/core/dnsserver
BenchmarkCoreServeDNS-4   	 1000000	      1429 ns/op	      16 B/op	       1 allocs/op
~~~

* README.md updates
This commit is contained in:
Miek Gieben
2017-10-24 10:16:03 +01:00
committed by GitHub
parent 5f813bcc21
commit fcd0342e42
15 changed files with 269 additions and 120 deletions

View File

@@ -76,13 +76,12 @@ kubernetes [ZONES...] {
## Examples
Handle all queries in the `cluster.local` zone. Connect to Kubernetes in-cluster.
Also handle all `PTR` requests for `10.0.0.0/16` . Verify the existence of pods when answering pod
requests. Resolve upstream records against `10.102.3.10`. Note we show the entire server block
here:
Handle all queries in the `cluster.local` zone. Connect to Kubernetes in-cluster. Also handle all
`in-addr.arpa` `PTR` requests for `10.0.0.0/17` . Verify the existence of pods when answering pod
requests. Resolve upstream records against `10.102.3.10`. Note we show the entire server block here:
~~~ txt
10.0.0.0/16 cluster.local {
10.0.0.0/17 cluster.local {
kubernetes {
pods verified
upstream 10.102.3.10:53