configure: Improve the use of delegate_to

[mamedin]

When getting the hostname from archivematica_src_configure_ss_url and
archivematica_src_configure_dashboardsettings dictionaries to be used with
the delegate_to keywork, it could fail when delegated host has different IP
address or hostname from ansible host than the one used by the pipeline host.
For instance, it is on a private network or different DNS zone.

Adding the new variables archivematica_src_configure_ss_inventory_hostname
and archivematica_src_configure_atom_inventory_hostname allows to configure
the delegate_to destination with other hostname or IP address.

Connects to #280

[scollazo]

Should we use SS_URL on those cases?

[mamedin]

Should we use SS_URL on those cases?

Do you mean using https://github.com/artefactual-labs/ansible-archivematica-src/blob/stable/1.10.x/tasks/configure.yml#L59 ?

It should be the same than the archivematica_src_configure_ss_url. This url is used by dashboard server with SS API. Imagine that URL has a hostname from a local DNS domain and you are not using the same DNS server than the AM servers in your ansible host. Then you need to use a fake /etc/hosts entry. It could makes sense when you are the only person that deploys/upgrade the system, but could be a problem for the next one that tries to deploy/upgrade it.

Defining these variables will fix that potential (and weird) issue.

[mamedin]

Other potential case: When the remote host needs a ssh proxy.