adding master api project

Master/master/schema/instanceschema.py

@@ -0,0 +1,29 @@
+from marshmallow import Schema, fields, post_load, validate
+from master.models.instancemodel import InstanceModel
+from master.schema.serverschema import ServerSchema
+
+class InstanceSchema(Schema):
+    id = fields.String(
+        required=True
+    )
+    version = fields.Float(
+        required=True,
+        validate=validate.Range(1.0, 10.0, 'invalid version number')
+    )
+    servers = fields.Nested(
+        ServerSchema,
+        many=True,
+        validate=validate.Length(0, 32, 'invalid server count')
+    )
+    uptime = fields.Int(
+        required=True,
+        validate=validate.Range(0, 2147483647, 'invalid uptime')
+    )
+    last_heartbeat = fields.Int(
+        required=False
+    )
+
+    @post_load
+    def make_instance(self, data):
+        return InstanceModel(**data)
+