Hi all,

Every week, I see a user confused by the domain, system_domain, and
app_domains properties in the Cloud Foundry manifest. The confusion is
primarily around domain and system_domain. These properties can be
confusing even for the core development teams, since these global
properties are used by many different jobs coming from many different
projects, and the usage may be inconsistent.

I propose we consolidate on system_domain. Here's where the other
property, domain, is currently used:

$ grep -r ' domain:' -- */spec
blobstore/spec: domain:
cloud_controller_clock/spec: domain:
cloud_controller_ng/spec: domain:
cloud_controller_worker/spec: domain:
dea_next/spec: domain:
hm9000/spec: domain:
uaa/spec: domain:
uaa/spec: domain: <(String) domain for cookie, default is incoming
request domain>

Details:

- *uaa* job spec actually says it's deprecated, so we can just delete it
- *hm9000* doesn't actually use it, it probably used to when it
registered its own route
- *dea* seems to only use it for directory server, and can probably
safely use system_domain instead
- *cloud_controller_ng & friends* use both domain and system_domain, but
the CAPI team has concluded that only system_domain is needed.

I just wanted to give the community a heads-up on this coming change. I'll
ask the PMs of the various teams to try to remove these properties from
their BOSH job specs, and the Release Integration team will then make sure
to remove it from any manifest generation templates and documentation.

Cheers,
Amit