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 9fa69ce6d469fe9a2b8fd92a09df74ea993e6b81..16362a98a5895f16fb6d4dc598a3d21180a83203 100644 (file)
--- 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 6c4d13d4f8a90f89e45a49b355d73ed76f037af6..2dd2e417ccc6cbc161006a9e08d780b6ed41bfb5 100644 (file)
--- 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