upgrade to pymongo 3.0 breaks pymongo connection

[timfeirg]

error message as follows:

Exception Type: ConnectionError
Exception Value:    
Cannot connect to database dashboard :
False is not a read preference.

# local variables from django output
conn_settings = {'host': '10.6.2.41', 'port': 27017, 'read_preference': False}
connection_settings  = {'authentication_source': None, 'host': '10.6.2.41', 'port': 27017, 'read_preference': False}

You can see the problem is in 'read_preference', which in mongnengine is False by default, which no longer is valid in pymongo.

[rozza]

pymongo 3.0 has just been released and the latest version of pymongo is automatically installed when pip installing mongoengine.

[rozza]

@thedrow @DavidBord I think you might need to release a 0.9.1 with a locked version of pymongo < 3.0 until a pymongo 3.0 compatible version is released.

[rozza]

In the meantime please downgrade pymongo to 2.8:

pip install pymongo==2.8

[thedrow]

I'm on it.

[MRigal]

You're on the 0.9.1 or on the compatibility fix? Else I could work on the 3.0 connection fix

[thedrow]

If you can work on the connection fix that would be best.

[MRigal]

OK, I did my best, it fixes this issue, but needs some more work on other points, #946

[MRigal]

What about the 0.9.1 @thedrow ?

[shea256]

thank you @rozza this downgrade worked perfectly

[thedrow]

@MRigal I'm waiting for votes on #946.
If it's mergable I'll release 0.9.1.

[MRigal]

PyMongo3 support was merged in master, you may use it directly or wait a bit of time for next mongoengine release