rose: added documentation

doc/configuration.rst

@@ -469,3 +469,66 @@ Limitations
   NSEC or NSEC3 is supported) nor DNSSEC signed records.  However,
   since the module is hooked in the query processing plan, it will be
   possible to do online signing in the future.
+
+``rose`` - Static resource records
+---------------------------------------
+
+The module provides a mean to override responses for certain queries before the record is searched in
+the available zones. The modules comes with a tool ``rosedb_tool`` to manipulate with the database
+of static records.
+
+*Note: An entry in the database matches anything at or below it, i.e. 'myrecord.com' matches 'a.a.myrecord.com' as well.
+This can be exploited to create a catch-all entries.*
+
+For example, suppose we have a database of following records::
+
+        myrecord.com. 3600 IN A 127.0.0.1
+        www.myrecord.com. 3600 IN A 127.0.0.2
+        ipv6.myrecord.com. 3600 IN AAAA ::1
+
+And we query the nameserver with following::
+
+        $ kdig IN A myrecord.com
+          ... returns NOERROR, 127.0.0.1
+        $ kdig IN A www.myrecord.com
+          ... returns NOERROR, 127.0.0.2
+        $ kdig IN A stuff.myrecord.com
+          ... returns NOERROR, 127.0.0.1
+        $ kdig IN AAAA myrecord.com
+          ... returns NXDOMAIN
+        $ kdig IN AAAA ipv6.myrecord.com
+          ... returns NOERROR, ::1 
+        
+In addition the module is able to log matching queries via remote syslog if you specify a syslog address endpoint and an
+optional string code.
+
+Here is an example on how to use the module:
+
+* Create the entries in the database::
+
+        $ mkdir /tmp/static_rrdb 
+        $ rosedb_tool /tmp/static_rrdb add myrecord.com. A 3600 "127.0.0.1" "-" "-" # No logging
+        $ rosedb_tool /tmp/static_rrdb add www.myrecord.com. A 3600 "127.0.0.1" "www_query" "10.0.0.1" # Syslog @ 10.0.0.1 
+        $ rosedb_tool /tmp/static_rrdb add ipv6.myrecord.com. AAAA 3600 "::1" "ipv6_query" "10.0.0.1" # Syslog @ 10.0.0.1 
+        $ rosedb_tool /tmp/static_rrdb list # Verify
+        www.myrecord.com.       A RDATA=10B     www_query       10.0.0.1
+        ipv6.myrecord.com.      AAAA RDATA=22B  ipv6_query      10.0.0.1
+        myrecord.com.           A RDATA=10B     -               -
+
+ *Note: the database may be modified while the server is running later on.*
+
+* Configure the query module and start the server::
+
+        $ vim knot.conf
+        knot.conf:
+        zones {
+                query_module {
+                        rosedb "/tmp/static_rrdb";
+                }
+        }
+
+        $ knotd -c knot.conf
+
+* Verify the running instance::
+
+        $ kdig @127.0.0.1#6667 A myrecord.com