mirror of
https://github.com/coredns/coredns.git
synced 2025-10-31 18:23:13 -04:00
71ee323651
* add upstream @self and loop count * 1st round of feedback * allow argless upstream * update test * readmes * feedback
134 lines
4.1 KiB
Markdown
134 lines
4.1 KiB
Markdown
# etcd
|
|
|
|
## Name
|
|
|
|
*etcd* - enables reading zone data from an etcd instance.
|
|
|
|
## Description
|
|
|
|
The data in etcd has to be encoded as
|
|
a [message](https://github.com/skynetservices/skydns/blob/2fcff74cdc9f9a7dd64189a447ef27ac354b725f/msg/service.go#L26)
|
|
like [SkyDNS](https://github.com/skynetservices/skydns). It should also work just like SkyDNS.
|
|
|
|
The etcd plugin makes extensive use of the proxy plugin to forward and query other servers in the
|
|
network.
|
|
|
|
## Syntax
|
|
|
|
~~~
|
|
etcd [ZONES...]
|
|
~~~
|
|
|
|
* **ZONES** zones etcd should be authoritative for.
|
|
|
|
The path will default to `/skydns` the local etcd proxy (http://localhost:2379). If no zones are
|
|
specified the block's zone will be used as the zone.
|
|
|
|
If you want to `round robin` A and AAAA responses look at the `loadbalance` plugin.
|
|
|
|
~~~
|
|
etcd [ZONES...] {
|
|
stubzones
|
|
fallthrough [ZONES...]
|
|
path PATH
|
|
endpoint ENDPOINT...
|
|
upstream [ADDRESS...]
|
|
tls CERT KEY CACERT
|
|
}
|
|
~~~
|
|
|
|
* `stubzones` enables the stub zones feature. The stubzone is *only* done in the etcd tree located
|
|
under the *first* zone specified.
|
|
* `fallthrough` If zone matches but no record can be generated, pass request to the next plugin.
|
|
If **[ZONES...]** is omitted, then fallthrough happens for all zones for which the plugin
|
|
is authoritative. If specific zones are listed (for example `in-addr.arpa` and `ip6.arpa`), then only
|
|
queries for those zones will be subject to fallthrough.
|
|
* **PATH** the path inside etcd. Defaults to "/skydns".
|
|
* **ENDPOINT** the etcd endpoints. Defaults to "http://localhost:2379".
|
|
* `upstream` upstream resolvers to be used resolve external names found in etcd (think CNAMEs)
|
|
pointing to external names. If you want CoreDNS to act as a proxy for clients, you'll need to add
|
|
the proxy plugin. If no **ADDRESS** is given, CoreDNS will resolve CNAMEs against itself.
|
|
**ADDRESS** can be an IP address, and IP:port or a string pointing to a file that is structured
|
|
as /etc/resolv.conf.
|
|
* `tls` followed by:
|
|
|
|
* no arguments, if the server certificate is signed by a system-installed CA and no client cert is needed
|
|
* a single argument that is the CA PEM file, if the server cert is not signed by a system CA and no client cert is needed
|
|
* two arguments - path to cert PEM file, the path to private key PEM file - if the server certificate is signed by a system-installed CA and a client certificate is needed
|
|
* three arguments - path to cert PEM file, path to client private key PEM file, path to CA PEM
|
|
file - if the server certificate is not signed by a system-installed CA and client certificate
|
|
is needed.
|
|
|
|
## Examples
|
|
|
|
This is the default SkyDNS setup, with everying specified in full:
|
|
|
|
~~~ corefile
|
|
. {
|
|
etcd skydns.local {
|
|
stubzones
|
|
path /skydns
|
|
endpoint http://localhost:2379
|
|
upstream 8.8.8.8:53 8.8.4.4:53
|
|
}
|
|
prometheus
|
|
cache 160 skydns.local
|
|
loadbalance
|
|
proxy . 8.8.8.8:53 8.8.4.4:53
|
|
}
|
|
~~~
|
|
|
|
Or a setup where we use `/etc/resolv.conf` as the basis for the proxy and the upstream
|
|
when resolving external pointing CNAMEs.
|
|
|
|
~~~ corefile
|
|
. {
|
|
etcd skydns.local {
|
|
path /skydns
|
|
upstream /etc/resolv.conf
|
|
}
|
|
cache 160 skydns.local
|
|
proxy . /etc/resolv.conf
|
|
}
|
|
~~~
|
|
|
|
Multiple endpoints are supported as well.
|
|
|
|
~~~
|
|
etcd skydns.local {
|
|
endpoint http://localhost:2379 http://localhost:4001
|
|
...
|
|
~~~
|
|
|
|
|
|
### Reverse zones
|
|
|
|
Reverse zones are supported. You need to make CoreDNS aware of the fact that you are also
|
|
authoritative for the reverse. For instance if you want to add the reverse for 10.0.0.0/24, you'll
|
|
need to add the zone `0.0.10.in-addr.arpa` to the list of zones. Showing a snippet of a Corefile:
|
|
|
|
~~~
|
|
etcd skydns.local 10.0.0.0/24 {
|
|
stubzones
|
|
...
|
|
~~~
|
|
|
|
Next you'll need to populate the zone with reverse records, here we add a reverse for
|
|
10.0.0.127 pointing to reverse.skydns.local.
|
|
|
|
~~~
|
|
% curl -XPUT http://127.0.0.1:4001/v2/keys/skydns/arpa/in-addr/10/0/0/127 \
|
|
-d value='{"host":"reverse.skydns.local."}'
|
|
~~~
|
|
|
|
Querying with dig:
|
|
|
|
~~~ sh
|
|
% dig @localhost -x 10.0.0.127 +short
|
|
reverse.skydns.local.
|
|
~~~
|
|
|
|
## Bugs
|
|
|
|
Only the etcdv2 protocol is supported.
|