use different dns for different tests

Author: neerfri

rootfs/etc/nginx/lua/test/balancer_test.lua

@@ -1,6 +1,5 @@
 local cjson = require("cjson.safe")
 local util = require("util")
-local dns_cache = require("util.dns").__index._cache
 
 local balancer, expected_implementations, backends
 local original_ngx = ngx
@@ -97,7 +96,6 @@ describe("Balancer", function()
     reset_balancer()
     reset_expected_implementations()
     reset_backends()
-    dns_cache.flush_all()
   end)
 
   after_each(function()
@@ -443,9 +441,9 @@ describe("Balancer", function()
 
     it("sets balancer to nil when service is of type External name and DNS could not resolve", function()
       backend = {
-        name = "example-com", service = { spec = { ["type"] = "ExternalName" } },
+        name = "example2-com", service = { spec = { ["type"] = "ExternalName" } },
         endpoints = {
-          { address = "example.com", port = "80", maxFails = 0, failTimeout = 0 }
+          { address = "example2.com", port = "80", maxFails = 0, failTimeout = 0 }
         }
       }