test: drop meta from vtest.config_new()

The test function used to return 2 values: config and its meta.
The meta could be used to retrieve certain sections of the config
by name, without knowing the automatically generated UUIDs.

The approach appeared to be too clumsy in the next patches. It
would be easier to get UUIDs from the instances like this patch
does.

Part of #325

test/luatest_helpers/server.lua

@@ -160,6 +160,16 @@ function Server:instance_uuid()
     return uuid
 end
 
+function Server:replicaset_uuid()
+    -- Cache the value when found it first time.
+    if self.replicaset_uuid_value then
+        return self.replicaset_uuid_value
+    end
+    local uuid = self:exec(function() return box.info.cluster.uuid end)
+    self.replicaset_uuid_value = uuid
+    return uuid
+end
+
 -- TODO: Add the 'wait_for_readiness' parameter for the restart()
 -- method.
 
@@ -192,6 +202,7 @@ function Server:cleanup()
     end
     self.instance_id_value = nil
     self.instance_uuid_value = nil
+    self.replicaset_uuid_value = nil
 end
 
 function Server:drop()

test/luatest_helpers/vtest.lua

@@ -21,13 +21,9 @@ end
 local function config_new(templ)
     local res = table.deepcopy(templ)
     local sharding = {}
-    local meta = {replicasets = {}}
     res.sharding = sharding
     for i, replicaset_templ in pairs(templ.sharding) do
         local replicaset_uuid = uuid_next()
-        meta.replicasets[i] = {
-            uuid = replicaset_uuid
-        }
         local replicas = {}
         local replicaset = table.deepcopy(replicaset_templ)
         replicaset.replicas = replicas
@@ -40,7 +36,7 @@ local function config_new(templ)
         end
         sharding[replicaset_uuid] = replicaset
     end
-    return res, meta
+    return res
 end
 
 --

test/router-luatest/router_test.lua

@@ -4,7 +4,7 @@ local vutil = require('vshard.util')
 local wait_timeout = 120
 
 local g = t.group('router')
-local cluster_cfg, cfg_meta = vtest.config_new({
+local cluster_cfg = vtest.config_new({
     sharding = {
         {
             replicas = {
@@ -206,9 +206,11 @@ g.test_map_callrw_raw = function(g)
             err = err,
         }
     end, {wait_timeout})
+    local rs1_uuid = g.replica_1_a:replicaset_uuid()
+    local rs2_uuid = g.replica_2_a:replicaset_uuid()
     local expected = {
-        [cfg_meta.replicasets[1].uuid] = {{1, 3}},
-        [cfg_meta.replicasets[2].uuid] = {{2, 3}},
+        [rs1_uuid] = {{1, 3}},
+        [rs2_uuid] = {{2, 3}},
     }
     t.assert_equals(res.val, expected, 'map callrw success')
     t.assert_equals(res.map_type, 'userdata', 'values are msgpacks')
@@ -226,7 +228,7 @@ g.test_map_callrw_raw = function(g)
                                         return_raw = true})
     end, {wait_timeout})
     expected = {
-        [cfg_meta.replicasets[1].uuid] = {{1}},
+        [rs1_uuid] = {{1}},
     }
     t.assert_equals(res, expected, 'map callrw without one value success')
     --
@@ -248,7 +250,7 @@ g.test_map_callrw_raw = function(g)
         type = 'ClientError',
         message = 'map_err'
     }, 'error object')
-    t.assert_equals(err_uuid, cfg_meta.replicasets[2].uuid, 'error uuid')
+    t.assert_equals(err_uuid, rs2_uuid, 'error uuid')
     --
     -- Cleanup.
     --