Document the ALIAS record, closes #2394

diff --git a/docs/markdown/authoritative/howtos.md b/docs/markdown/authoritative/howtos.md
index a6c07bb7eeae551bf5ef48171834350e56278aed..ce215fc244df64f061cdf0c8e22e4b79fbf88cb0 100644 (file)
--- a/docs/markdown/authoritative/howtos.md
+++ b/docs/markdown/authoritative/howtos.md
@@ -1,3 +1,28 @@
+# Using ALIAS records
+The ALIAS record provides a way to have CNAME-like behaviour on the zone apex.
+
+In order to correctly serve ALIAS records, set the [`recursor`](settings.md#recursor)
+setting to an existing resolver and add the ALIAS record to your zone apex. e.g.:
+
+```
+recursor=[::1]:5300
+```
+
+```
+$ORIGIN example.net
+$TTL 1800
+
+@ IN SOA ns1.example.net. hostmaster.example.net. 2015121101 1H 15 1W 2H
+
+@ IN NS ns1.example.net.
+
+@ IN ALIAS mywebapp.paas-provider.net.
+```
+
+When the authoritative server receives a query for the A-record for `example.net`,
+it will resolve the A record for `mywebapp.paas-provider.net` and serve an answer
+for `example.net` with that A record.
+
 # CDS & CDNSKEY Key Rollover
 If the upstream registry supports [RFC 7344](https://tools.ietf.org/html/rfc7344)
 key rollovers you can use several [`pdnsutil`](dnssec.md#pdnsutil) commands to do

diff --git a/docs/markdown/types.md b/docs/markdown/types.md
index bfe1f615a2cb39002f2692ca328b917b2ebf1a1e..5b03d2cb385bbbd453c6add635115fdbd32eba64 100644 (file)
--- a/docs/markdown/types.md
+++ b/docs/markdown/types.md
@@ -14,6 +14,12 @@ The AAAA record contains an IPv6 address. An example: '2001:DB8:2000:bf0::1'.
 ## AFSDB
 Since 2.9.21. Specialised record type for the 'Andrew Filesystem'. Stored as: '\#subtype hostname', where subtype is a number.
 
+## ALIAS
+Since 4.0.0, the ALIAS pseudo-record type is supported to provide CNAME-like
+mechanisms on a zone's apex. See the [howto](authoritative/howtos.md#using-alias-records)
+for information on how to configure PowerDNS to serve records synthesized from
+ALIAS records.
+
 ## CERT
 Since 2.9.21. Specialised record type for storing certificates, defined in [RFC 2538](http://tools.ietf.org/html/rfc2538).