Emissary

emissary is a data plane for Envoy https://github.com/envoyproxy/data-plane-api/blob/master/XDS_PROTOCOL.md

Resolvers

emissary can currently use Consul or the Docker API as resolvers.

Docker Resolver

The Docker resolver will be looking for a label to identify the destination containers for Envoy. By default the label is emissary.service_name but can be override in the configuration.

Development

dep ensure
make

make will build a single executable emissary and tag a docker image emissary:latest

Run the tests using make:

$ make test
# For more verbosity (`Q=` trick applies to all targets)
$ make test Q=

Examples

The examples directory currently has two examples you can run locally with docker-compose

• eds_grpc
• eds_az_aware_grpc

cd eds_grpc
make
docker-compose up

cd eds_az_aware_grpc
make
docker-compose up

Each example starts 2 "server" containers with a trivial http server listening on port 8077. It then starts an envoy instance to serve as the loadbalancer for the upstream server cluster. Additionally we start a consul and registrator containers. Finally we start a client which connects to envoy

The examples share the same containers so if you start and stop different examples you may need to clean your stopped containers

docker rm $(docker ps -qa --no-trunc --filter "status=exited")