Getting Mongo dump - juju/juju GitHub Wiki
On controller machine, run:
mongodump -h 127.0.0.1 --port 37017 --ssl -u admin -p <password> --authenticationDatabase admin --db juju
On juju 2.1, this seems to be wrong, and the following is required:
/usr/lib/juju/mongo*/bin/mongodump --host 127.0.0.1 --port 37017 --authenticationDatabase admin --ssl --sslAllowInvalidCertificates --username "$user" --password "$password"
(Where $user and $password are the correct values from the page linked below.)
How to get or mongo client installed on the controller machine, please follow Login into Mongo