Planning: end-to-end testing of JeroMQ with other flavors of ZeroMQ

[daveyarwood]

Spun off of #472. See that issue for some initial discussion.

I think this should probably end up being a separate repo within the zeromq org, since it will encompass more than just JeroMQ, and test failures might not indicate problems with JeroMQ.

@fredoboulo mentioned determining if there is a set of well-known and stable releases of libzmq that flawlessly implement the different protocols. I pondered if libzmq (use of the C library directly) might be considered the "gold standard" against which we measure other ZMQ implementations.

Opening this issue for discussion & planning.

[trevorbernard]

libzmq is the reference implementation of the various ZMTP protocols. Setting up the various matrices shouldn't be that difficult but will require some resources. I would focus on testing upgrading/downgrading between ZMTP protocols, and cross implementation security.

[fredoboulo]

I would vote for libzmq, as Trevor stated this is the reference implementation.

[fbacchella]

circleci make easy to add external running docker images to a build. I use it to test an application again ElasticSearch. It's simply:

        docker:
            - image: circleci/openjdk:11-jdk
            - image: docker.elastic.co/elasticsearch/elasticsearch:6.6.0
              environment:
                  discovery.type: single-node

The first is the main docker image, the other is an added running image. So some docker images with a few libzmq server could do the trick.
They could be used by all the zmq familly bindings.