From: Marek Vavruša <marek.vavrusa@nic.cz>
Date: Thu, 7 May 2015 19:41:16 +0000 (+0200)
Subject: daemon/lua: syntactic sugar for ‘net’
X-Git-Tag: v1.0.0-beta1~201
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b4bf01aa74ba873e73ed176051e4df34cac9a33;p=thirdparty%2Fknot-resolver.git

daemon/lua: syntactic sugar for ‘net’

this allows list-like declaration of bound interfaces

e.g. net = { ‘127.0.0.1’, net.eth0 }
---

diff --git a/daemon/README.rst b/daemon/README.rst
index 9fa69ce6d..16362a98a 100644
--- a/daemon/README.rst
+++ b/daemon/README.rst
@@ -112,16 +112,16 @@ The possible simple data types are strings, integers or floats and boolean.
 Dynamic configuration
 ^^^^^^^^^^^^^^^^^^^^^
 
-Knowing that the the configuration is a valid Lua script enables you to write dynamic rules, and also avoid
-additional configuration templating. One example is to differentiate between internal and external
-interfaces based on environment variable.
+Knowing that the the configuration is a Lua in disguise enables you to write dynamic rules, and also avoid
+repetition and templating. This is unavoidable with static configuration, e.g. when you want to configure
+each node a little bit differently.
 
 .. code-block:: lua
 
 	if hostname() == 'hidden' then
-		net.listen(net.eth0)
+		net.listen(net.eth0, 5353)
 	else
-		net.listen(net.eth1.addr[1])
+		net = { '127.0.0.1', net.eth1.addr[1] }
 	end
 
 Another example would show how it is possible to bind to all interfaces, using iteration.
@@ -221,6 +221,14 @@ Environment
 Network configuration
 ^^^^^^^^^^^^^^^^^^^^^
 
+For when listening on ``localhost`` just doesn't cut it.
+
+.. tip:: Use declarative interface for network.
+
+         .. code-block:: lua
+
+         	net = { '127.0.0.1', net.eth0, net.eth1.addr[1] }
+
 .. function:: net.listen(address, [port = 53])
 
    :return: boolean
diff --git a/daemon/lua/sandbox.lua b/daemon/lua/sandbox.lua
index 6c4d13d4f..2dd2e417c 100644
--- a/daemon/lua/sandbox.lua
+++ b/daemon/lua/sandbox.lua
@@ -16,12 +16,19 @@ setmetatable(env, {
 
 -- Quick access to interfaces
 -- `net.<iface>` => `net.interfaces()[iface]`
+-- `net = {addr1, ..}` => `net.listen(name, addr1)`
 setmetatable(net, {
 	__index = function (t, k)
 		local v = rawget(t, k)
 		if v then return v
 		else return net.interfaces()[k]
 		end
+	end,
+	__newindex = function (t,k,v)
+		local iname = rawget(net.interfaces(), v)
+		if iname then t.listen(iname)
+		else t.listen(v)
+		end
 	end
 })
 
@@ -29,10 +36,11 @@ setmetatable(net, {
 -- `modules.<name> = <config>`
 setmetatable(modules, {
 	__newindex = function (t,k,v)
+		if type(k) == 'number' then k = v end
 		if not rawget(_G, k) then
 			modules.load(k)
 			local mod = rawget(_G, k)
-			if mod and mod['config'] then
+			if k ~= v and mod and mod['config'] then
 				mod['config'](v)
 			end