Set default redhat dbpath to /var/lib/mongo

[h-haaks]

Pull Request (PR) description

Aligns the default dbpath with rpm package content.

RedHat and derivative users with existing deployments relying on the module default should explicitly set dbpath to the old default before upgrading the module.

This Pull Request (PR) fixes the following issues

Fixes #714

[smortex]

If a parameter default value is system-dependant, we should remove any default value from the manifest and only provide values from Hiera in order for the documentation not pointing to the wrong direction:

puppet-mongodb/manifests/server.pp

Line 326 in b6d3f5f

Stdlib::Absolutepath $dbpath = '/var/lib/mongodb',

If I understand correctly this is a backward-incompatible change?

[h-haaks]

If a parameter default value is system-dependant, we should remove any default value from the manifest and only provide values from Hiera in order for the documentation not pointing to the wrong direction

I fixed this for all but the mongodb::server::journal parameter.
This parameter is optinal and there is another nojournal parameter controlling the same parameter in mongod.conf ...

puppet-mongodb/templates/mongodb.conf.erb

Lines 47 to 51 in 05f973d

	<% if @nojournal -%>
	storage.journal.enabled: false
	<% elsif @journal -%>
	storage.journal.enabled: true
	<% end -%>

[h-haaks]

If I understand correctly this is a backward-incompatible change?

You are absolutely right. Existing databases has to be moved manually or the folder renamed before running puppet with this change. Otherwise the module will create new empty databases in the new location.

[smortex]

LGTM. Because it is a backwards incompatible change, maybe the first message of the PR could be adjusted to explicitly detail who is affected by the change (RedHat and derivative users) and what they should do when updating (mv /var/lib/mongodb /var/lib/mongo).