Turns out that files with just service methods don't get loaded into the
descriptor pool automatically in C++. So, needed to have some messages
in ads.proto. Turns out this was a good opportunity to move some of the
messages that were related to discovery out of base.proto.
This shouldn't break the API, since everything is in the envoy.api.v2
packge space.
This is a design-level update to bootstrap.proto, that plumbs in the
remaining top-level config from v1. It will probably have some small
changes made beyond this as we implement.
Notable differences to v1 are:
* Static/dynamic resources are clearly delineated at top-level, clusters no longer belong to the ClusterManager object.
* Stats sinks are a repeated list of opaque configs, similar to filter.
* Some simplifications to object types, e.g. RLS no longer specifies type (do we want to preserve the v1 generality here?).
Also renamed RLDS back to RLS, I'll admit that it didn't make sense to
cram it into the xDS namespace, it's really a very distinct service on
the data plane and shouldn't be bundled with the control plane services.
This patch adds a static bootstrap proto that is expected to be provided
on the filesystem or command-line. This should enable Envoy to then
either fetch the rest of config from disk or reach out to the various
management servers for the rest of the APIs.
Fixes#93.