gistfile1.lua

require 'socket'
math.randomseed(socket.gettime()*10000)
local logger = logger
local pairs = pairs
local type = type
 
local log_error = log_error
local dnspacket = dnspacket
 
 
local domains_id = {}
local domains_name = {}
local records = {}
 
 
 
domains_name["test.ru"] = {domain_id = 11, name = "test.ru", type = "NATIVE", soa = { hostmaster = "hostmaster.he.net", nameserver = "ns.test.cc", serial = 2005092521, refresh = 28800, retry = 7200, expire = 604800, default_ttl = 86400, ttl = 3600 } }
domains_id["11"] = domains_name["test.ru"] 
 
 
records["test.ru"] = { 
    {domain_id = 11,name = "test.ru", type = "NS", ttl = 120, content = "ns.test.cc"},
    {domain_id = 11, weight=50 ,name = "test.ru", type = "A", ttl = 120, content = "1.1.1.1"},
    {domain_id = 11, weight=25  ,name = "test.ru", type = "A", ttl = 120, content = "2.2.2.2"},
    {domain_id = 11, weight=25  ,name = "test.ru", type = "A", ttl = 120, content = "3.3.3.3"}
    
}
 
 
function list(target, domain_id)
    logger(log_error, "(l_list)", "target:", target, " domain_id:", domain_id )
    
    return false
end
 
local size, c, r, n, nn, q_type, q_name, domainid
local remote_ip, remote_port, local_ip
 
function lookup(qtype, qname, domain_id)
--    logger(log_error, "(l_lookup)", "qtype:", qtype, " qname:", qname, " domain_id:", domain_id )
    q_type = qtype
    q_name = qname
    domainid = domain_id
    
    r = records[q_name]
    
    c = 0
    size = 0
 
    remote_ip, remote_port, local_ip = dnspacket()
--    logger(log_error, "(l_lookup) dnspacket", "remote:", remote_ip, " port:", remote_port, " local:", local_ip)
 
    if type(r) == "table" then
        size = #r
    end
--    logger(log_error, "(l_lookup)", "size:", size)
end
 
function weighted_random_choice(choices)
  for k,v in pairs(choices) do
   logger(log_error, k,v)
  end
  local threshold = math.random(0, weighted_total(choices))
  local last_choice
  for choice, weight in pairs(choices) do
    threshold = threshold - weight
    if threshold <= 0 then return choice end
    last_choice = choice
  end
  return last_choice
end
 
function weighted_total(choices)
  local total = 0
  for choice, weight in pairs(choices) do
    total = total + weight
  end
  return total
end
 
 

local ip_wei = {}

function wei(r)
  for kk,vv in pairs(r) do
    if vv.type == "A" then
        ip_wei[vv.content] = vv.weight
    end
  end
      return weighted_random_choice(ip_wei)
end
 
local was_a = {} -- return only one A for all record
function get()
--    logger(log_error, "(l_get) BEGIN")
    -- r is record, c is field inside it
      while c < size do
        c = c + 1
      
        if (q_type == "ANY" or q_type == r[c]["type"]) then
            if (r[c]["type"] == "A" or q_type == "A") then
               if (next(was_a) ~= nil) then
                  r[c]["content"] = was_a["A"]
                  --logger(log_error, "was A is"..was_a["A"])
               else 
                 r[c]["content"] = wei(r)
                 was_a.A = r[c]["content"]
               end 
            end
            return r[c]
        end
      end
--    logger(log_error, "(l_get) END")
    return false
end
 
local k,v,kk,vv
 
function getsoa(name)
--    logger(log_error, "(l_getsoa) BEGIN", "name:", name)
 
    r = domains_name[name]
    if type(r) == "table" then
--      logger(log_error, type(r), type(r["soa"]))
        return r["soa"] 
    end
    
--    logger(log_error, "(l_getsoa) END NOT FOUND")
end
 
logger(log_error, "powerdns-luabackend starting up!")
 
 
for k,v in pairs(QTypes) do
--    logger(log_error, k, v)
end
 
for k,v in pairs(records) do
    for kk,vv in pairs(v) do
--      logger(log_error, kk, type(vv), vv["type"])
    end
end
 
 
 
 
 
 
 
 
примеры ответов:
 
 
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     46 1.1.1.1
     54 3.3.3.3
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     50 1.1.1.1
     50 3.3.3.3
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     50 1.1.1.1
     50 3.3.3.3
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     46 2.2.2.2
     54 1.1.1.1
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     49 2.2.2.2
     51 1.1.1.1
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     49 1.1.1.1
     51 2.2.2.2
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     20 1.1.1.1
     26 3.3.3.3
     54 2.2.2.2
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     25 1.1.1.1
     25 3.3.3.3
     50 2.2.2.2
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     25 1.1.1.1
     25 3.3.3.3
     50 2.2.2.2
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     25 1.1.1.1
     25 3.3.3.3
     50 2.2.2.2
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     27 2.2.2.2
     73 1.1.1.1
tj@nb:~/Dev/$ i=0 ; while [ $i -lt 100 ] ; do dig A test.ru @MY.NS.IP -p53 +short ; let i=i+1 ;done  | sort -d | uniq -c | sort -n
     25 2.2.2.2
     75 1.1.1.1


тест самой рандомной молотилки:


function weighted_random_choice(choices)
local threshold = math.random(0, weighted_total(choices))
local last_choice
for choice, weight in pairs(choices) do
threshold = threshold - weight
if threshold <= 0 then return choice end
last_choice = choice
end
return last_choice
end
 
function weighted_total(choices)
local total = 0
for choice, weight in pairs(choices) do
total = total + weight
end
return total
end
 
 
local choices = { foo = 20, bar = 10, baz = 5, waz = 2 }
local iterations = 1000
for i = 1, iterations do
print(weighted_random_choice(choices))
end
 
 
результат вполне нормальный: 
269 bar
149 baz
527 foo
55 waz