DOC: dns: explain set server ... fqdn requires resolver

Abhishek Gupta reported on discourse that set server [...] fqdn always
fails. Further investigation showed that this requires the internal
DNS resolver to be configured. Add this requirement to the docs.

Must be backported to 1.8.

diff --git a/doc/management.txt b/doc/management.txt
index ef9f865e9019d6c1cdfbbe1783e0652e07c06510..c78dc7486225ddf0ab465309a324d91c34d055cc 100644 (file)
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -1707,7 +1707,8 @@ set server <backend>/<server> weight <weight>[%]
   equivalent of the "set weight" command below.
 
 set server <backend>/<server> fqdn <FQDN>
-  Change a server's FQDN to the value passed in argument.
+  Change a server's FQDN to the value passed in argument. This requires the
+  internal run-time DNS resolver to be configured and enabled for this server.
 
 set severity-output [ none | number | string ]
   Change the severity output format of the stats socket connected to for the