The C++ Interceptors example shows how interceptors might be used with a simple key-value store. Note that the C++ Interception API is still experimental and subject to change.
The key-value store service is defined in keyvaluestore.proto.It has a simple bidi streaming RPC where the request messages contain a key and the response messages contain a value.
The example shows a very naive CachingInterceptor added on the client channel that caches the key-value pairs that it sees. If the client looks up a key present in the cache, the interceptor responds with its saved value and the server doesn't see the request for that key.
On the server-side, a very simple logging interceptor is added that simply logs to stdout whenever a new RPC is received.
To run the server -
$ tools/bazel run examples/cpp/interceptors:server
To run the client (on a different terminal) -
$ tools/bazel run examples/cpp/interceptors:client