I built mongodb 2.6.4 with SSL enabled from source following the official build documentation, and got mongod running fine on a newly provisioned Linux server.

I used a self-signed certificate and configured mongod as described in the Configure SSL docs. The key post of my config is:

...
net:
   bindIp: 127.0.0.1
   port: 27017
   ssl:
      mode: requireSSL
      PEMKeyFile: /opt/mongo/security/mongodb.pem
... 

To test I tried running mongo client with --ssl and I got the client console. Also I tried without the --ssl argument and connection was declined.

Next was connecting with the Ruby Driver. I installed 'mongo' gem and the installed version was v1.11.1. I used the following program derived from SSL Configuration for Clients sample:

require 'rubygems'
require 'mongo'
client = Mongo::MongoClient.new('localhost', 27017, {:ssl => true})

But when I run all I get is:

/home/test/.rvm/gems/ruby-1.9.3-p547/gems/mongo-1.11.1/lib/mongo/mongo_client.rb:422:in `connect': Failed to connect to a master node at localhost:27017 (Mongo::ConnectionFailure)
from /home/test/.rvm/gems/ruby-1.9.3-p547/gems/mongo-1.11.1/lib/mongo/mongo_client.rb:661:in `setup'
from /home/test/.rvm/gems/ruby-1.9.3-p547/gems/mongo-1.11.1/lib/mongo/mongo_client.rb:177:in `initialize'
from test_mongo_ssl.rb:8:in `new'
from test_mongo_ssl.rb:8:in `<main>'

As an experiment I also tried connecting using the Python driver:

from pymongo import MongoClient
c = MongoClient(host="localhost", port=27017, ssl=True)

And that connected fine. Therefore I am reaching the conclusion that there is an issue specifically with the Ruby driver. Or the driver's documentation doesn't accurately describe how one should connect to mongod with ssl enabled.