Comment 3 for bug 1760390

Note that those associated patches get the unit tests to run with Mongo 3.6 (if you have it locally), but does not provide everything needed to support 3.6 for "juju bootstrap". (We know we at least need to be passing --bind_ip_all to mongod startup when in HA mode.)

We are currently waiting for a 3.6 to be available in some sort of PPA or the Bionic archive to finish testing bootstrap.

See also bugs that were about upgrading to mongo 3.4 like:
https://bugs.launchpad.net/juju/+bug/1672967
https://bugs.launchpad.net/bugs/1756432

And
https://github.com/jameinel/juju/tree/2.3-bionic-mongodb-server-core

which is a spike to have Juju 2.3 support installing 'mongodb-server-core' on Bionic. Which might evolve to be Mongo 3.6 at which point we'll need to change the command line parameters we are passing.

There may be other issues supporting 3.6 but at least the test suite passes.