mgo r2014.03.12 with SASL/Kerberos support

[Gustavo Niemeyer]

The r2014.03.12 release of the mgo (http://labix.org/mgo) MongoDB driver for Go
was just tagged. This release has both new features and bug fixes, and is API
compatible with the prior release.

The following changes were made:

- Experimental SASL and Kerberos support.

To enable the feature, mgo must be built with the -tags sasl
option, which is disabled by default because it forces the
dynamic linkage with the system Cyrus SASL library.

The new Session.Login method takes the new mgo.Credential type as
a parameter for authenticating with mechanisms other than straight
username/password:

http://labix.org/v2/mgo#Session.Login
http://labix.org/v2/mgo#Credential

The mgo.DialInfo type also received new fields, matching those
in mgo.Credential, to establish the authentication at dial time:

http://labix.org/v2/mgo#DialInfo

The new DialInfo.Source field allows selecting a database for
authentication other than the default database, even when using
the standard username/password mechanism (MONGODB-CR).

These new options are also supported using URL parameters that
are common to all MongoDB drivers with Kerberos support (authSource,
authService, and gssapiServiceName):

http://labix.org/v2/mgo#Dial

For details on configuring the MongoDB server with Kerberos support,
see the documentation at: http://goo.gl/lQNL55


- Fixed improper lock handling during error on Iter.Next.

Problem reported by Evan Shaw.


- Prevent calling reply func twice on forcefully closed sockets.

There was a small chance that the reply handling function might
be called twice when a socket was killed during the reply
handling phase.

Problem reported by Francisco Souza and John Morales.




gustavo @ http://niemeyer.net