Trouble with configuring users and connecting to Mongo with PHP - php

Question

I installed mongo 3.0.0 on my ubuntu server.
I tried to use PHP (with appropriate lib installed) to connect to mongo to learn sth new. Unfortunaltey I cannot go any further.
My user configuration looks like this:
> use testdb
switched to db testdb
> show users
{
"_id" : "testdb.testdb",
"user" : "testdb",
"db" : "testdb",
"roles" : [
{
"role" : "readWrite",
"db" : "testdb"
}
]
}
Then I try to execute the following PHP code:
try{
$uri = "mongodb://testdb:password#xxx.xxx.xxx.xxx:27017/testdb";
$options = array("connectTimeoutMS" => 30000);
$client = new MongoClient($uri, $options );
}
catch(Exception $e) {
echo 'Message: ' .$e->getMessage();
die();
}
$db = $client->selectDB("testdb");
I get "Message: Failed to connect to: xxx.xxx.xxx.xxx:27017: Authentication failed on database 'testdb' with username 'testdb': auth failed".
In /etc/mongod.conf I have "auth = true" uncommented
I also verified the conncetion with:
> nc -w 3 -v xxx.xxx.xxx.xxx 27017 Connection to xxx.xxx.xxx.xxx 27017
> port [tcp/*] succeeded!
I dig through Internet, i spent few hours already on this, I even re-installed mongo and set everything up again without any success.
Could you point to where to look for solution?

Answer 1

The authentication schema of 3.0 is not compatible with 2.x drivers. One way you should be able to make it work is by downgrading the authentication mechanism:
use "admin"
var schema = db.system.version.findOne({"_id" : "authSchema"})
schema.currentVersion = 3
db.system.version.save(schema)
Then create a user and you should be able to connect with it.