无法使用 SQLAlchemy 从开发服务器连接到 Google Cloud SQL [英] Unable to connect to Google Cloud SQL from development server using SQLAlchemy

问题描述

我在我的开发工作站上使用 SQLAlchemy 0.7.9 连接到 Google Cloud SQL 失败(希望使用 create_all() 生成架构).我无法通过以下错误:

I've been unsuccessful at connecting to Google Cloud SQL using SQLAlchemy 0.7.9 from my development workstation (in hopes to generate the schema using create_all()). I can't get passed the following error:

sqlalchemy.exc.DBAPIError: (AssertionError) No api proxy found for service "rdbms" None None

我能够使用 google_sql.py instancename 成功连接到数据库实例，它最初打开一个浏览器来授权连接(现在似乎已经缓存了授权，尽管我没有没有 ~/Library/Preferences/com.google.cloud.plist 文件作为 https://developers.google.com/cloud-sql/docs/commandline 表示我应该)

I was able to successfully connect to the database instance using the google_sql.py instancename, which initially opened up a browser to authorize the connection (which now appears to have cached the authorization, although I don't have the ~/Library/Preferences/com.google.cloud.plist file as https://developers.google.com/cloud-sql/docs/commandline indicates I should)

这是我用来测试连接的简单应用程序:

Here is the simple application I'm using to test the connection:

from sqlalchemy import create_engine

engine = create_engine('mysql+gaerdbms:///myapp', connect_args={"instance":"test"})
connection = engine.connect()

此处提供完整的堆栈跟踪 - https://gist.github.com/4486641

The full stacktrace is available here - https://gist.github.com/4486641

推荐答案

事实证明 SQLAlchemy 中的 mysql+gaerdbms:/// 驱动程序仅设置为使用 rdbms_apiproxy DBAPI，只能在从 Google App Engine 实例访问 Google Cloud SQL 时使用.我向 SQLAlchemy 提交了一个 ticket 以更新驱动程序以使用基于 OAuth 的 rdbms_googleapi不是在 Google App Engine 上，就像 App Engine SDK 中提供的 Django 驱动程序一样.rdbms_googleapi 也是 google_sql.py 使用的 DBAPI(远程 sql 控制台).

It turns out the mysql+gaerdbms:/// driver in SQLAlchemy was only setup to use the rdbms_apiproxy DBAPI, which can only be used when accessing Google Cloud SQL from a Google App Engine instance. I submitted a ticket to SQLAlchemy to update the driver to use the OAuth-based rdbms_googleapi when not on Google App Engine, just like the Django driver provided in the App Engine SDK. rdbms_googleapi is also the DBAPI that google_sql.py uses (remote sql console).

更新的方言预计将成为 0.7.10 和 0.8.0 版本的一部分，但在它们可用之前，您可以执行以下操作:

The updated dialect is expected to be part of 0.7.10 and 0.8.0 releases, but until they are available, you can do the following:

1 - 将 ticket 中更新的方言复制到文件(例如 gaerdbms_dialect.py)

1 - Copy the updated dialect in the ticket to a file (ex. gaerdbms_dialect.py)

from sqlalchemy.dialects.mysql.mysqldb import MySQLDialect_mysqldb
from sqlalchemy.pool import NullPool
import re

"""Support for Google Cloud SQL on Google App Engine

Connecting
-----------

Connect string format::

    mysql+gaerdbms:///<dbname>?instance=<project:instance>


  # Example:
  create_engine('mysql+gaerdbms:///mydb?instance=myproject:instance1')
"""


class MySQLDialect_gaerdbms(MySQLDialect_mysqldb):

    @classmethod
    def dbapi(cls):
        from google.appengine.api import apiproxy_stub_map

        if apiproxy_stub_map.apiproxy.GetStub('rdbms'):
            from google.storage.speckle.python.api import rdbms_apiproxy
            return rdbms_apiproxy
        else:
            from google.storage.speckle.python.api import rdbms_googleapi
            return rdbms_googleapi

    @classmethod
    def get_pool_class(cls, url):
        # Cloud SQL connections die at any moment
        return NullPool

    def create_connect_args(self, url):
        opts = url.translate_connect_args()
        opts['dsn'] = ''  # unused but required to pass to rdbms.connect()
        opts['instance'] = url.query['instance']
        return [], opts

    def _extract_error_code(self, exception):
        match = re.compile(r"^(d+):").match(str(exception))
        code = match.group(1)
        if code:
            return int(code)

dialect = MySQLDialect_gaerdbms

<小时>

2 - 注册自定义方言(您可以覆盖现有架构)

---

2 - Register the custom dialect (you can override the existing schema)

from sqlalchemy.dialects import registry
registry.register("mysql.gaerdbms", "application.database.gaerdbms_dialect", "MySQLDialect_gaerdbms")

注意: 0.8 允许在当前进程中注册方言(如上所示).如果您运行的是旧版本的 SQLAlchemy，我建议升级到 0.8+ 或者您需要为方言创建单独的安装，如此处.

Note: 0.8 allows a dialect to be registered within the current process (as shown above). If you are running an older version of SQLAlchemy, I recommend upgrading to 0.8+ or you'll need to create a separate install for the dialect as outlined here.

3 - 更新您的 create_engine('...') url，因为项目和实例现在作为 URL 的查询字符串的一部分提供

3 - Update your create_engine('...') url as the project and instance are now provided as part of the query string of the URL

mysql+gaerdbms:///<dbname>?instance=<project:instance>

例如:

create_engine('mysql+gaerdbms:///mydb?instance=myproject:instance1')

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