This commit causes the scheduled queue maintainer to refresh
the queue config by calling the get_queue_config event approximately
every minute while the queue is alive.
In addition, we now thread the routing_domain through to get_queue_config
Augments our queue name format to be
`campaign:tenant@domain!routing_domain`.
The routing_domain is optional. If the routing_domain is not set, its
effective value is that of the recipient domain.
You can `msg:set_meta('routing_domain', 'bar.com')` to set the
routing_domain for a message, so if the original recipient was
`user@foo.com`, that would cause the computed queue name for it to be
`foo.com!bar.com`.
The routing_domain is used when deciding on the ready_queue name
and destination MXs, so continuing our example, instead of resolving
`foo.com` MX records we'd resolve `bar.com` and deliver to that site.
The `get_egress_path_config` event `domain` parameter is redefined to be
the effective `routing_domain`.
The `get_queue_config` event `domain` parameter is the regular recipient
domain. The `routing_domain` is not currently made available to
`get_queue_config`. If/when we expose it, it will likely be via a
queue name object instead of adding an additional parameter. That would
be a breaking change.
The consequence of not exposing this parameter is that per-message
routing scenarios for the same domain (but different routing domains)
cannot vary the scheduled queue parmeters (eg: retry intervals). Even
though they would have separate scheduled queue instances, those
instances would have the same scheduled queue parameters. If you need
to be able to do that, then explicitly setting the domain portion of the
queue name would be a way to do that: `msg:set_meta('queue',
'foo.com-via-bar.com!bar.com')`. `get_queue_config` would then be
called with `domain='foo.com-via-bar.com'` and your policy could then
respond accordingly.
To facilitate this, formatlize the `campaign:tenant@domain` naming
and add a helper type to parse and format that tuple of information
to make it easier to work with in the code.
Adjust the get_x_config events to accept those parameters.
Wez Furlong
Mike Hillyer