refactor lua balancer and fix ipv6 issue

rootfs/etc/nginx/lua/balancer.lua

@@ -135,18 +135,17 @@ function _M.balance()
     return
   end
 
-  local host, port = balancer:balance()
-  if not (host and port) then
-    ngx.log(ngx.WARN,
-      string.format("host or port is missing, balancer: %s, host: %s, port: %s", balancer.name, host, port))
+  local peer = balancer:balance()
+  if not peer then
+    ngx.log(ngx.WARN, "no peer was returned, balancer: " .. balancer.name)
     return
   end
 
   ngx_balancer.set_more_tries(1)
 
-  local ok, err = ngx_balancer.set_current_peer(host, port)
+  local ok, err = ngx_balancer.set_current_peer(peer)
   if not ok then
-    ngx.log(ngx.ERR, "error while setting current upstream peer to " .. tostring(err))
+    ngx.log(ngx.ERR, "error while setting current upstream peer: " .. tostring(err))
   end
 end
 

rootfs/etc/nginx/lua/balancer/chash.lua

@@ -1,7 +1,6 @@
 local balancer_resty = require("balancer.resty")
 local resty_chash = require("resty.chash")
 local util = require("util")
-local split = require("util.split")
 
 local _M = balancer_resty:new({ factory = resty_chash, name = "chash" })
 
@@ -15,8 +14,7 @@ end
 
 function _M.balance(self)
   local key = util.lua_ngx_var(self.hash_by)
-  local endpoint_string = self.instance:find(key)
-  return split.split_pair(endpoint_string, ":")
+  return self.instance:find(key)
 end
 
 return _M

rootfs/etc/nginx/lua/balancer/ewma.lua

@@ -128,7 +128,8 @@ function _M.balance(self)
     endpoint = pick_and_score(peer_copy, k)
   end
 
-  return endpoint.address, endpoint.port
+  -- TODO(elvinefendi) move this processing to _M.sync
+  return endpoint.address .. ":" .. endpoint.port
 end
 
 function _M.after_balance(_)

rootfs/etc/nginx/lua/balancer/round_robin.lua

@@ -1,7 +1,6 @@
 local balancer_resty = require("balancer.resty")
 local resty_roundrobin = require("resty.roundrobin")
 local util = require("util")
-local split = require("util.split")
 
 local _M = balancer_resty:new({ factory = resty_roundrobin, name = "round_robin" })
 
@@ -14,8 +13,7 @@ function _M.new(self, backend)
 end
 
 function _M.balance(self)
-  local endpoint_string = self.instance:find()
-  return split.split_pair(endpoint_string, ":")
+  return self.instance:find()
 end
 
 return _M

rootfs/etc/nginx/lua/balancer/sticky.lua

@@ -1,7 +1,6 @@
 local balancer_resty = require("balancer.resty")
 local resty_chash = require("resty.chash")
 local util = require("util")
-local split = require("util.split")
 local ck = require("resty.cookie")
 
 local _M = balancer_resty:new({ factory = resty_chash, name = "sticky" })
@@ -56,7 +55,7 @@ local function pick_random(instance)
   return instance:next(index)
 end
 
-local function sticky_endpoint_string(self)
+function _M.balance(self)
   local cookie, err = ck:new()
   if not cookie then
     ngx.log(ngx.ERR, err)
@@ -73,9 +72,4 @@ local function sticky_endpoint_string(self)
   return self.instance:find(key)
 end
 
-function _M.balance(self)
-  local endpoint_string = sticky_endpoint_string(self)
-  return split.split_pair(endpoint_string, ":")
-end
-
 return _M

rootfs/etc/nginx/lua/test/balancer/chash_test.lua

@@ -21,9 +21,8 @@ describe("Balancer chash", function()
       }
       local instance = balancer_chash:new(backend)
 
-      local host, port = instance:balance()
-      assert.equal("10.184.7.40", host)
-      assert.equal("8080", port)
+      local peer = instance:balance()
+      assert.equal("10.184.7.40:8080", peer)
     end)
   end)
 end)

rootfs/etc/nginx/lua/test/balancer/ewma_test.lua

@@ -11,9 +11,8 @@ describe("Balancer ewma", function()
       }
       local instance = balancer_ewma:new(backend)
 
-      local host, port = instance:balance()
-      assert.equal("10.184.7.40", host)
-      assert.equal("8080", port)
+      local peer = instance:balance()
+      assert.equal("10.184.7.40:8080", peer)
     end)
 
     it("picks the endpoint with lowest score when there two of them", function()
@@ -32,9 +31,8 @@ describe("Balancer ewma", function()
       ngx.shared.balancer_ewma_last_touched_at.get = function(self, key) return t end
 
 
-      local host, port = instance:balance()
-      assert.equal("10.184.97.100", host)
-      assert.equal("8080", port)
+      local peer = instance:balance()
+      assert.equal("10.184.97.100:8080", peer)
     end)
   end)