Heroku MySQL DB Error with Flask

Question

I'm trying to host a local MySQL database using ClearDB on Heroku. The build is successful, but when I try to access the application, the application fails.

Here is my app.py code (it fails on the first line):

db = MySQLdb.connect(host="localhost", user="root", db="database")
cur = db.cursor()
query = """SELECT * from database"""
cur.execute(query)
data = cur.fetchall()

Here is the log output:

2016-06-01T14:48:48.720931+00:00 heroku[web.1]: Starting process with command `python app.py`
2016-06-01T14:48:51.790883+00:00 app[web.1]:   File "app.py", line 30, in <module>
2016-06-01T14:48:51.790864+00:00 app[web.1]: Traceback (most recent call last):
2016-06-01T14:48:51.790910+00:00 app[web.1]:     db = MySQLdb.connect(host="localhost", user="root", db="database")
2016-06-01T14:48:51.790981+00:00 app[web.1]: _mysql_exceptions.OperationalError: (2002, "Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)")
2016-06-01T14:48:51.790911+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/MySQLdb/__init__.py", line 81, in Connect
2016-06-01T14:48:51.790912+00:00 app[web.1]:     return Connection(*args, **kwargs)
2016-06-01T14:48:51.790912+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/MySQLdb/connections.py", line 193, in __init__
2016-06-01T14:48:51.790937+00:00 app[web.1]:     super(Connection, self).__init__(*args, **kwargs2)
2016-06-01T14:48:52.491629+00:00 heroku[web.1]: Process exited with status 1

Here is what heroku config prints:

CLEARDB_DATABASE_URL: mysql://actualurl
DATABASE_URL:         mysql://actualurl
MYSQL_DB:             database
MYSQL_HOST:           localhost
MYSQL_USER:           root

Answer 1

There's no point in posting your Heroku config, because it's clear that your app isn't using it. You have hardcoded the database host as "localhost", rather than using the DATABASE_URL environment variable.