Name: coredns
Owner: Rancher
Description: CoreDNS is a DNS server that chains plugins
Created: 2017-11-08 09:31:04.0
Updated: 2018-05-15 01:46:41.0
Pushed: 2018-04-23 08:49:44.0
Homepage: https://coredns.io
Size: 51319
Language: Go
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CoreDNS (written in Go) chains plugins. Each plugin performs a DNS function.
CoreDNS is a Cloud Native Computing Foundation incubating level project.
CoreDNS is a fast and flexible DNS server. The keyword here is flexible: with CoreDNS you are able to do what you want with your DNS data by utilizing plugins. If some functionality is not provided out of the box you can add it by writing a plugin.
CoreDNS can listen for DNS request coming in over UDP/TCP (go'old DNS), TLS (RFC 7858) and gRPC (not a standard).
Currently CoreDNS is able to:
version.bind
and friends (chaos).And more. Each of the plugins is documented. See coredns.io/plugins for all in-tree plugins, and coredns.io/explugins for all out-of-tree plugins.
Check out the project and do dependency resolution with:
get github.com/coredns/coredns
Some of the dependencies require Go version 1.9 or later.
We vendor most (not all!) packages. Building from scratch is easiest, by just using make
:
ke
This should yield a coredns
binary.
CoreDNS requires Go to compile. However, if you already have docker installed and prefer not to setup a Go environment, you could build CoreDNS easily:
cker run --rm -i -t -v $PWD:/go/src/github.com/coredns/coredns \
-w /go/src/github.com/coredns/coredns golang:1.10 make
The above command alone will have coredns
binary generated.
When starting CoreDNS without any configuration, it loads the
whoami plugin and starts listening on port 53 (override with
-dns.port
), it should show the following:
/09/18 09:20:50 [INFO] CoreDNS-001
DNS-001
Any query send to port 53 should return some information; your sending address, port and protocol used.
If you have a Corefile without a port number specified it will, by default, use port 53, but you
can override the port with the -dns.port
flag:
./coredns -dns.port 1053
, runs the server on port 1053.
Start a simple proxy, you'll need to be root to start listening on port 53.
Corefile
contains:
{
forward . 8.8.8.8:53
log
Just start CoreDNS: ./coredns
. Then just query on that port (53). The query should be forwarded to
8.8.8.8 and the response will be returned. Each query should also show up in the log which is
printed on standard output.
Serve the (NSEC) DNSSEC-signed example.org
on port 1053, with errors and logging sent to standard
output. Allow zone transfers to everybody, but specifically mention 1 IP address so that CoreDNS can
send notifies to it.
ple.org:1053 {
file /var/lib/coredns/example.org.signed {
transfer to *
transfer to 2001:500:8f::53
}
errors
log
Serve example.org
on port 1053, but forward everything that does not match example.org
to a recursive
nameserver and rewrite ANY queries to HINFO.
53 {
rewrite ANY HINFO
forward . 8.8.8.8:53
file /var/lib/coredns/example.org.signed example.org {
transfer to *
transfer to 2001:500:8f::53
}
errors
log
IP addresses are also allowed. They are automatically converted to reverse zones:
.0.0/24 {
whoami
Means you are authoritative for 0.0.10.in-addr.arpa.
.
This also works for IPv6 addresses. If for some reason you want to serve a zone named 10.0.0.0/24
add the closing dot: 10.0.0.0/24.
as this also stops the conversion.
This even works for CIDR (See RFC 1518 and 1519) addressing, i.e. 10.0.0.0/25
, CoreDNS will then
check if the in-addr
request falls in the correct range.
Listening on TLS and for gRPC? Use:
//example.org grpc://example.org {
whoami
Specifying ports works in the same way:
://example.org:1443 {
# ...
When no transport protocol is specified the default dns://
is assumed.
We're most active on Slack (and Github):
More resources can be found:
Examples for deployment via systemd and other use cases can be found in the deployment repository.
If you find a security vulnerability or any security related issues,
please DO NOT file a public issue, instead send your report privately to
security@coredns.io
. Security reports are greatly appreciated and we
will publicly thank you for it.