Remove ucloud_common and put its files under ucloud.common subpackage.

Remove individual config.py used by every component and put them into single config.py ucloud/config.py
Use /etc/ucloud/ucloud.conf for Environment Variables
Refactoring and a lot of it
Make ucloud repo a package and different components of ucloud a subpackage for avoiding code duplication.
Improved logging.

metadata/config.py

@@ -1,22 +0,0 @@
-import logging
-
-from etcd3_wrapper import Etcd3Wrapper
-from decouple import config
-
-from ucloud_common.vm import VmPool
-
-logging.basicConfig(
-    level=logging.DEBUG,
-    filename="log.txt",
-    filemode="a",
-    format="%(asctime)s: %(levelname)s - %(message)s",
-    datefmt="%d-%b-%y %H:%M:%S",
-)
-
-
-VM_PREFIX = config("VM_PREFIX")
-USER_PREFIX = config("USER_PREFIX")
-
-etcd_client = Etcd3Wrapper(host=config("ETCD_URL"))
-
-VM_POOL = VmPool(etcd_client, VM_PREFIX)

metadata/main.py

@@ -2,14 +2,15 @@ import os
 
 from flask import Flask, request
 from flask_restful import Resource, Api
-from config import etcd_client, VM_POOL, USER_PREFIX
+
+from config import etcd_client, env_vars, vm_pool
 
 app = Flask(__name__)
 api = Api(app)
 
 
 def get_vm_entry(mac_addr):
-    return next(filter(lambda vm: mac_addr in list(zip(*vm.network))[1], VM_POOL.vms), None)
+    return next(filter(lambda vm: mac_addr in list(zip(*vm.network))[1], vm_pool.vms), None)
 
 
 # https://stackoverflow.com/questions/37140846/how-to-convert-ipv6-link-local-address-to-mac-address-in-python
@@ -43,8 +44,8 @@ class Root(Resource):
             return {'message': 'Metadata for such VM does not exists.'}, 404
         else:
 
-            # {user_prefix}/{realm}/{name}/key
-            etcd_key = os.path.join(USER_PREFIX, data.value['owner_realm'],
+            # {env_vars.get('USER_PREFIX')}/{realm}/{name}/key
+            etcd_key = os.path.join(env_vars.get('USER_PREFIX'), data.value['owner_realm'],
                                     data.value['owner'], 'key')
             etcd_entry = etcd_client.get_prefix(etcd_key, value_in_json=True)
             user_personal_ssh_keys = [key.value for key in etcd_entry]
@@ -81,5 +82,10 @@ class Root(Resource):
 
 api.add_resource(Root, '/')
 
-if __name__ == '__main__':
+
+def main():
     app.run(debug=True, host="::", port="80")
+
+
+if __name__ == '__main__':
+    main()