gRPC Bridge

Envoy gRPC

The gRPC bridge sandbox is an example usage of Envoy’s gRPC bridge filter. Included in the sandbox is a gRPC in-memory Key/Value store with a Python HTTP client. The Python client makes HTTP/1 requests through the Envoy sidecar process which are upgraded into HTTP/2 gRPC requests. Response trailers are then buffered and sent back to the client as a HTTP/1 header payload.

Another Envoy feature demonstrated in this example is Envoy’s ability to do authority base routing via its route configuration.

Building the Go service

To build the Go gRPC service run:

$ pwd
envoy/examples/grpc-bridge
$ script/bootstrap.sh
$ script/build.sh

Note: build.sh requires that your Envoy codebase (or a working copy thereof) is in $GOPATH/src/github.com/envoyproxy/envoy.

Docker compose

To run the docker compose file, and set up both the Python and the gRPC containers run:

$ pwd
envoy/examples/grpc-bridge
$ docker-compose pull
$ docker-compose up --build

Sending requests to the Key/Value store

To use the Python service and send gRPC requests:

$ pwd
envoy/examples/grpc-bridge
# set a key
$ docker-compose exec python /client/client.py set foo bar
setf foo to bar

# get a key
$ docker-compose exec python /client/client.py get foo
bar

# modify an existing key
$ docker-compose exec python /client/client.py set foo baz
setf foo to baz

# get the modified key
$ docker-compose exec python /client/client.py get foo
baz

In the running docker-compose container, you should see the gRPC service printing a record of its activity:

grpc_1    | 2017/05/30 12:05:09 set: foo = bar
grpc_1    | 2017/05/30 12:05:12 get: foo
grpc_1    | 2017/05/30 12:05:18 set: foo = baz