Adds new REST API v2/

Addresses #5269

scripts/lua/rest/v2/get/dns/resolve.lua

@@ -0,0 +1,57 @@
+--
+-- (C) 2013-21 - ntop.org
+--
+
+dirs = ntop.getDirs()
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+require "lua_utils"
+local json = require ("dkjson")
+local rest_utils = require("rest_utils")
+
+--
+-- Resolve a name
+-- Example: curl -u admin:admin -H "Content-Type: application/json" -d '{"hostname" : "www.google.com"}' http://localhost:3000/lua/rest/v2/get/dns/resolve.lua
+--
+-- NOTE: in case of invalid login, no error is returned but redirected to login
+--
+
+local rc = rest_utils.consts.success.ok
+local res = {}
+
+local hostname = _GET["hostname"]
+
+if isEmptyString(hostname) then
+   rest_utils.answer(rest_utils.consts.err.invalid_args)
+   return
+end
+
+if string.find(hostname, '://') then
+   -- Looks like an URI, strip the scheme
+   local uri_info = string.split(hostname, "://")
+   if #uri_info == 2 then
+      hostname = uri_info[2]
+   end
+end
+
+if string.find(hostname, ':') then
+   local host_port_info = string.split(hostname, ":")
+   if #host_port_info == 2 then
+      -- Looks like host:port, strip the port
+      hostname = host_port_info[1]
+   end
+end
+
+local resolved = ntop.resolveHost(hostname, true --[[ IPv4 --]])
+if not resolved then
+   resolved = ntop.resolveHost(hostname, false --[[ IPv6 --]])
+end
+
+if not resolved then
+   rest_utils.answer(rest_utils.consts.err.resolution_failed)
+   return
+end
+
+res = resolved
+
+rest_utils.answer(rc, res)