internal: master presence check for get space

Added validation of the master presence in replicaset and the
master connection to the `utils.get_space` method before
receiving the space from the connection.

Closes #331

Author: GRISHNOV

CHANGELOG.md

@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 
 ### Fixed
+* Added validation of the master presence in replicaset and the 
+  master connection to the `utils.get_space` method before 
+  receiving the space from the connection (#331).
 
 ## [0.14.1] - 10-11-22
 

crud/borders.lua

@@ -74,7 +74,10 @@ local function call_get_border_on_router(vshard_router, border_name, space_name,
     })
 
     local replicasets = vshard_router:routeall()
-    local space = utils.get_space(space_name, replicasets)
+    local space, err = utils.get_space(space_name, replicasets)
+    if err ~= nil then
+        return nil, BorderError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, BorderError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end

crud/common/utils.lua

@@ -15,6 +15,7 @@ local FlattenError = errors.new_class("FlattenError", {capture_stack = false})
 local UnflattenError = errors.new_class("UnflattenError", {capture_stack = false})
 local ParseOperationsError = errors.new_class('ParseOperationsError', {capture_stack = false})
 local ShardingError = errors.new_class('ShardingError', {capture_stack = false})
+local GetSpaceError = errors.new_class('GetSpaceError')
 local GetSpaceFormatError = errors.new_class('GetSpaceFormatError', {capture_stack = false})
 local FilterFieldsError = errors.new_class('FilterFieldsError', {capture_stack = false})
 local NotInitializedError = errors.new_class('NotInitialized')
@@ -97,13 +98,37 @@ end
 
 function utils.get_space(space_name, replicasets)
     local replicaset = select(2, next(replicasets))
+
+    if replicaset == nil then
+        return nil, GetSpaceError:new(
+            'The router returned empty replicasets: ' ..
+            'perhaps other instances are unavailable or you have configured only the router')
+    end
+
+    if replicaset.master == nil then
+        local error_msg = string.format(
+            'The master was not found in replicaset %s, ' ..
+            'check status of the master and repeat the operation later',
+             replicaset.uuid)
+        return nil, GetSpaceError:new(error_msg)
+    end
+
+    if replicaset.master.conn.error ~= nil then
+        local error_msg = string.format(
+            'The connection to the master of replicaset %s is not valid: %s',
+             replicaset.uuid, replicaset.master.conn.error)
+        return nil, GetSpaceError:new(error_msg)
+    end
     local space = replicaset.master.conn.space[space_name]
 
     return space
 end
 
 function utils.get_space_format(space_name, replicasets)
-    local space = utils.get_space(space_name, replicasets)
+    local space, err = utils.get_space(space_name, replicasets)
+    if err ~= nil then
+        return nil, GetSpaceFormatError:new("An error occurred during the operation: %s", err)
+    end
     if space == nil then
         return nil, GetSpaceFormatError:new("Space %q doesn't exist", space_name)
     end

crud/count.lua

@@ -137,7 +137,10 @@ local function call_count_on_router(vshard_router, space_name, user_conditions,
         return nil, CountError:new("Failed to get router replicasets: %s", err)
     end
 
-    local space = utils.get_space(space_name, replicasets)
+    local space, err = utils.get_space(space_name, replicasets)
+    if err ~= nil then
+        return nil, CountError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, CountError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end

crud/delete.lua

@@ -62,7 +62,10 @@ local function call_delete_on_router(vshard_router, space_name, key, opts)
         vshard_router = '?string|table',
     })
 
-    local space = utils.get_space(space_name, vshard_router:routeall())
+    local space, err = utils.get_space(space_name, vshard_router:routeall())
+    if err ~= nil then
+        return nil, DeleteError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, DeleteError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end

crud/get.lua

@@ -65,7 +65,10 @@ local function call_get_on_router(vshard_router, space_name, key, opts)
         vshard_router = '?string|table',
     })
 
-    local space = utils.get_space(space_name, vshard_router:routeall())
+    local space, err = utils.get_space(space_name, vshard_router:routeall())
+    if err ~= nil then
+        return nil, GetError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, GetError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end

crud/insert.lua

@@ -64,7 +64,10 @@ local function call_insert_on_router(vshard_router, space_name, original_tuple,
         vshard_router = '?string|table',
     })
 
-    local space = utils.get_space(space_name, vshard_router:routeall())
+    local space, err = utils.get_space(space_name, vshard_router:routeall())
+    if err ~= nil then
+        return nil, InsertError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, InsertError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end

crud/insert_many.lua

@@ -131,7 +131,12 @@ local function call_insert_many_on_router(vshard_router, space_name, original_tu
         vshard_router = '?string|table',
     })
 
-    local space = utils.get_space(space_name, vshard_router:routeall())
+    local space, err = utils.get_space(space_name, vshard_router:routeall())
+    if err ~= nil then
+        return nil, {
+            InsertManyError:new("An error occurred during the operation: %s", err)
+        }, const.NEED_SCHEMA_RELOAD
+    end
     if space == nil then
         return nil, {InsertManyError:new("Space %q doesn't exist", space_name)}, const.NEED_SCHEMA_RELOAD
     end

crud/len.lua

@@ -64,7 +64,10 @@ function len.call(space_name, opts)
         return nil, LenError:new(err)
     end
 
-    local space = utils.get_space(space_name, vshard_router:routeall())
+    local space, err = utils.get_space(space_name, vshard_router:routeall())
+    if err ~= nil then
+        return nil, LenError:new("An error occurred during the operation: %s", err)
+    end
     if space == nil then
         return nil, LenError:new("Space %q doesn't exist", space_name)
     end

crud/replace.lua

@@ -66,9 +66,8 @@ local function call_replace_on_router(vshard_router, space_name, original_tuple,
 
     local space, err = utils.get_space(space_name, vshard_router:routeall())
     if err ~= nil then
-        return nil, ReplaceError:new("Failed to get space %q: %s", space_name, err), const.NEED_SCHEMA_RELOAD
+        return nil, ReplaceError:new("An error occurred during the operation: %s", err), const.NEED_SCHEMA_RELOAD
     end
-
     if space == nil then
         return nil, ReplaceError:new("Space %q doesn't exist", space_name), const.NEED_SCHEMA_RELOAD
     end