test: fixes the moduleless error of crud instance

In crud tests, if the necessary rocks dependencies are missing,
an error message is now displayed. Prior to this fix,
an error in importing missing models caused the tests to freez forever.

Part of #205

Author: GRISHNOV

Diff for: test/suites/crud_server.lua

@@ -1,7 +1,58 @@
 #!/usr/bin/env tarantool
 
-local crud = require('crud')
-local vshard = require('vshard')
+local function configure_crud_instance(primary_listen, crud, vshard)
+    box.schema.create_space(
+    'tester', {
+    format = {
+        {name = 'id', type = 'unsigned'},
+        {name = 'bucket_id', type = 'unsigned'},
+        {name = 'name', type = 'string'},
+    }
+    })
+    box.space.tester:create_index('primary_index', {
+        parts = {
+            {field = 1, type = 'unsigned'},
+        },
+    })
+    box.space.tester:create_index('bucket_id', {
+        parts = {
+            {field = 2, type = 'unsigned'},
+        },
+        unique = false,
+    })
+
+    -- Setup vshard.
+    _G.vshard = vshard
+    box.once('guest', function()
+        box.schema.user.grant('guest', 'super')
+    end)
+    local uri = '[email protected]:' .. primary_listen
+    local cfg = {
+        bucket_count = 300,
+        sharding = {
+            [box.info().cluster.uuid] = {
+                replicas = {
+                    [box.info().uuid] = {
+                        uri = uri,
+                        name = 'storage',
+                        master = true,
+                    },
+                },
+            },
+        },
+    }
+    vshard.storage.cfg(cfg, box.info().uuid)
+    vshard.router.cfg(cfg)
+    vshard.router.bootstrap()
+
+    -- Initialize crud.
+    crud.init_storage()
+    crud.init_router()
+    crud.cfg{stats = true}
+end
+
+local crud_imported, crud = pcall(require, 'crud')
+local vshard_imported, vshard = pcall(require, 'vshard')
 
 local admin_listen = os.getenv("ADMIN")
 local primary_listen = os.getenv("LISTEN")
@@ -18,51 +69,19 @@ box.schema.user.grant(
     'read,write,execute',
     'universe'
 )
-box.schema.create_space(
- 'tester', {
-  format = {
-    {name = 'id', type = 'unsigned'},
-    {name = 'bucket_id', type = 'unsigned'},
-    {name = 'name', type = 'string'},
-  }
-})
-box.space.tester:create_index('primary_index', {
-    parts = {
-        {field = 1, type = 'unsigned'},
-    },
-})
-box.space.tester:create_index('bucket_id', {
-    parts = {
-        {field = 2, type = 'unsigned'},
-    },
-    unique = false,
-})
-
--- Setup vshard.
-_G.vshard = vshard
-box.once('guest', function()
-    box.schema.user.grant('guest', 'super')
-end)
-local uri = '[email protected]:' .. primary_listen
-local cfg = {
-    bucket_count = 300,
-    sharding = {
-        [box.info().cluster.uuid] = {
-            replicas = {
-                [box.info().uuid] = {
-                    uri = uri,
-                    name = 'storage',
-                    master = true,
-                },
-            },
-        },
-    },
-}
-vshard.storage.cfg(cfg, box.info().uuid)
-vshard.router.cfg(cfg)
-vshard.router.bootstrap()
 
--- Initialize crud.
-crud.init_storage()
-crud.init_router()
-crud.cfg{stats = true}
+if crud_imported == false or vshard_imported == false then
+    local fail_msg = 'The crud/vshard modules are not detected, ' ..
+                     'installation via rocks install is required ' ..
+                     'for CRUD testing purposes. You can use ' ..
+                     '<tarantoolctl rocks install crud> or ' ..
+                     '<tt rocks install crud> to install modules'
+    -- The print output will be captured in the logs.
+    print(fail_msg)
+    -- Because of the implementation of the testing framework,
+    -- this will cause the crash of the CRUD test and display to user
+    -- a message about require fail during instance configuration.
+    box.info.status = fail_msg
+else
+    configure_crud_instance(primary_listen, crud, vshard)
+end