Python, Nameko, nameko-sqlalchemy : Error : db_uris = self.container.config[DB_URIS_KEY] KeyError:

Question

大家好，

首先，我想让你知道，我才刚刚开始了解python微服务库Nameko。

我正在尝试创建一个简单的微服务，使用nameko-sqlalchemy扩展在Sqlite数据库中添加用户。当我尝试使用Nameko命令运行微服务时：Nameko run user_service，我得到错误：

Connected to amqp://guest:**@127.0.0.1:5672//
starting services: userService
Traceback (most recent call last):
File "/home/yek/Documents/my_development/micro_service_project/ms_env/lib/python3.6/site-packages/eventlet/hubs/hub.py", line 461, in fire_timers
timer()
File "/home/yek/Documents/my_development/micro_service_project/ms_env/lib/python3.6/site-packages/eventlet/hubs/timer.py", line 59, in __call__
cb(*args, **kw)
File "/home/yek/Documents/my_development/micro_service_project/ms_env/lib/python3.6/site-packages/eventlet/greenthread.py", line 221, in main
result = function(*args, **kwargs)
File "/home/yek/Documents/my_development/micro_service_project/ms_env/lib/python3.6/site-packages/nameko/utils/concurrency/__init__.py", line 76, in call
return getattr(item, name)(*args, **kwargs)
File "/home/yek/Documents/my_development/micro_service_project/ms_env/lib/python3.6/site-packages/nameko_sqlalchemy/database_session.py", line 24, in setup
db_uris = self.container.config[DB_URIS_KEY]
KeyError: 'DB_URIS'

我使用以下代码：

user_service.py

from nameko_sqlalchemy import DatabaseSession
from nameko.rpc import rpc
from nameko.containers import ServiceContainer
from model import DeclarativeBase
from model import User
class UserService(object):
name = 'userService'
db = DatabaseSession(DeclarativeBase)
@rpc
def write_to_db(self, user_id, first_name, last_name):
user = User(user_id, first_name, last_name)
with self.db.get_session() as session:
session.add(user)
session.commit()

CONFIG = {
"AMQP_URI":"amqp://guest:guest@localhost",
"DB_URIS":
{"userService:Base":"sqlite:///data.db"}
}
container = ServiceContainer(UserService,config=CONFIG)
service_extention = list(container.extensions)
container.start()
container.stop()

带有：

型号.py

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, DateTime

DeclarativeBase = declarative_base()
class User(DeclarativeBase):
__tablename__ = "users"
user_id = Column(Integer,primary_key=True)
first_name = Column(String)
last_name = Column(String)
def __init__(self, user_id, first_name, last_name):
self.user_id = user_id
self.first_name = first_name
self.last_name = last_name 

if __name__ == "__main__":
from sqlalchemy import create_engine
engine = create_engine('sqlite:///data.db', echo = True)
DeclarativeBase.metadata.create_all(engine)

环境：nameko 2.12.0/nameko sqlalchemy 1.5.0/Ubuntu 18.04.4 LTS/Python 3.6.9/Virtualenv

提前感谢您的帮助。

谨致问候，Younes

Answer 1

在学习了官方文档后，我发现了运行代码的方法出了什么问题。

解决方案是：

1. 直接使用Nameko CLI，如下所述，但添加了配置文件。新命令如下所示：nameko run user_service--config/config.yaml./config.yaml

AMQP_URI: 'amqp://guest:guest@localhost'
DB_URIS:
'userService:Base': 'sqlite:///data.db'

2. 添加service Container或Runner后，使用dict传递的配置直接运行user_service.py文件。解决方案每次使用都需要运行python文件。我想我用第二种方式错过了一些东西

我希望它会有所帮助。