fix(*) cassandra contact points initialization

kong/db/strategies/cassandra/connector.lua

@@ -14,7 +14,77 @@ function CassandraConnector.new(kong_config)
   do
     -- Resolve contact points before instantiating cluster, since the
     -- driver does not support hostnames in the contact points list.
+
+    -- TODO: this is an ugly hack to force lua sockets on a third party library
+
+    local tcp_old = ngx.socket.tcp
+    local udp_old = ngx.socket.udp
+
+    local dns_no_sync_old = kong_config.dns_no_sync
+
+    package.loaded["socket"] = nil
+    package.loaded["kong.tools.dns"] = nil
+    package.loaded["resty.dns.client"] = nil
+    package.loaded["resty.dns.resolver"] = nil
+
+    ngx.socket.tcp = function(...)
+      local tcp = require("socket").tcp(...)
+      return setmetatable({}, {
+        __newindex = function(_, k, v)
+          tcp[k] = v
+        end,
+        __index = function(_, k)
+          if type(tcp[k]) == "function" then
+            return function(_, ...)
+              if k == "send" then
+                local value = select(1, ...)
+                if type(value) == "table" then
+                  return tcp.send(tcp, table.concat(value))
+                end
+
+                return tcp.send(tcp, ...)
+              end
+
+              return tcp[k](tcp, ...)
+            end
+          end
+
+          return tcp[k]
+        end
+      })
+    end
+
+    ngx.socket.udp = function(...)
+      local udp = require("socket").udp(...)
+      return setmetatable({}, {
+        __newindex = function(_, k, v)
+          udp[k] = v
+        end,
+        __index = function(_, k)
+          if type(udp[k]) == "function" then
+            return function(_, ...)
+              if k == "send" then
+                local value = select(1, ...)
+                if type(value) == "table" then
+                  return udp.send(udp, table.concat(value))
+                end
+
+                return udp.send(udp, ...)
+              end
+
+              return udp[k](udp, ...)
+            end
+          end
+
+          return udp[k]
+        end
+      })
+    end
+
     local dns_tools = require "kong.tools.dns"
+
+    kong_config.dns_no_sync = true
+
     local dns = dns_tools(kong_config)
 
     for i, cp in ipairs(kong_config.cassandra_contact_points) do
@@ -28,6 +98,16 @@ function CassandraConnector.new(kong_config)
         resolved_contact_points[i] = ip
       end
     end
+
+    kong_config.dns_no_sync = dns_no_sync_old
+
+    package.loaded["resty.dns.resolver"] = nil
+    package.loaded["resty.dns.client"] = nil
+    package.loaded["kong.tools.dns"] = nil
+    package.loaded["socket"] = nil
+
+    ngx.socket.udp = udp_old
+    ngx.socket.tcp = tcp_old
   end
 
   if #resolved_contact_points == 0 then

spec/02-integration/02-cmd/02-start_stop_spec.lua

@@ -57,6 +57,18 @@ describe("kong start/stop #" .. strategy, function()
     assert(helpers.kong_exec("start --conf " .. helpers.test_conf_path))
     assert.truthy(helpers.path.exists(helpers.test_conf.kong_env))
   end)
+
+  if strategy == "cassandra" then
+    it("start resolves cassandra contact points", function()
+      assert(helpers.kong_exec("start", {
+        database = strategy,
+        cassandra_contact_points = "localhost",
+        cassandra_keyspace = helpers.test_conf.cassandra_keyspace,
+      }))
+      assert(helpers.kong_exec("stop"))
+    end)
+  end
+
   it("creates prefix directory if it doesn't exist", function()
     finally(function()
       helpers.kill_all("foobar")
@@ -342,6 +354,25 @@ describe("kong start/stop #" .. strategy, function()
       end
     end)
 
+    if strategy == "cassandra" then
+      it("errors when cassandra contact points cannot be resolved", function()
+        local ok, stderr = helpers.kong_exec("start --prefix " .. helpers.test_conf.prefix, {
+          database = strategy,
+          cassandra_contact_points = "invalid.inexistent.host",
+          cassandra_keyspace = helpers.test_conf.cassandra_keyspace,
+        })
+
+        assert.False(ok)
+        assert.matches("could not resolve any of the provided Cassandra contact points " ..
+                       "(cassandra_contact_points = 'invalid.inexistent.host')", stderr, nil, true)
+
+        finally(function()
+          helpers.kill_all()
+          pcall(helpers.dir.rmtree)
+        end)
+      end)
+    end
+
     if strategy == "off" then
       it("does not start with an invalid declarative config file", function()
         local yaml_file = helpers.make_yaml_file [[