protobuf has a `go_package` option that can be used to explicitly name
Go packages such that they can be imported without additional rewrites.
This allows us to store proto files without additional, redundant
directories (which were used for packaging hints, previously).
This change adds an explicit `go_package` to all .proto files and
updates `bin/protoc-go.sh` to ensure these packages are output into
$GOPATH (so that the go_package can be absolute). This removes the need
to manually rewrite imports in bin/protoc-go.sh.
Currently, the mock controller, which is used in tests, takes all of its
updates a priori, which makes it hard to control when an update occurs within a
test.
Now, the controller exposes a `DstSender`, which wraps an unbounded channel of
destination updates. This allows tests to trigger updates at a specific point
in the test.
In order to accomplish this, the controller's hand-rolled gRPC server
implementation has been discarded in favor of a real gRPC destination service.
This requires that the `controller-grpc` project now builds both clients
and servers for the destination service. Additionally, we now build a tap
client as well (assuming that we'll want to write tests against our tap
server).
The proxy depends on `protoc`-generated gRPC bindings to communicate
with the controller. In order to generate these bindings, build-time
dependencies must be compiled.
In order to support a more granular, cacheable build scheme, a new crate
has been created to house these gRPC bindings,
`conduit-proxy-controller-grpc`.
Because `TryFrom` and `TryInto` conversions are implemented for
protobuf-defined types, the `convert` module also had to be moved to
into a dedicated crate.
Furthermore, because the proxy's tests require that
`quickcheck::Aribtrary` be implemented for protobuf types, the
`conduit-proxy-controller-grpc` crate supports an _arbitrary_ feature
fla protobuf types, the `conduit-proxy-controller-grpc` crate supports
an _arbitrary_ feature flag.
While we're moving these libraries around, the `tower-router` crate has
been moved to `proxy/router` and renamed to `conduit-proxy-router.`
`futures-mpsc-lossy` has been moved into the proxy directory but has not
been renamed.
Finally, the `proxy/Dockerfile-deps` image has been updated to avoid the
wasteful building of dependency artifacts, as they are not actually used
by `proxy/Dockerfile`.
Oliver Gould