This repo contains all you need in order to use LCM inside a Docker container.
NOTE: Due to the presence of a virtualization layer when running linux images in Docker for Mac, it is not possible to exchange messages between the container and the Mac host. For further info about this issue, check the section Run on Mac below.
Move to the main directory of this repository and run
docker build -t ripl/lcm:latest ./
To deploy a new container that can talk to a (Linux) host and other Docker containers via LCM, run
docker run -it --net=host ripl/lcm:latest
| Host | Containers | Tunnel | Executed | Works? |
|---|---|---|---|---|
| Mac | 1 | No | ✔️ | ✖️ |
| Linux | 1 | No | ✔️ | ✔️ |
| Linux | 2 | No | ✔️ | ✔️ |
| Mac | 1 | Yes | ✖️ | TBA |
| Mac | 2 | Yes | ✖️ | TBA |
As of August 2018, the driver used by Docker to virtualize the network on Mac does not implement multicasting, thus it is not possible to exchange data between Mac host and Docker linux using LCM.
Nevertheless, there is still hope. A third-party implementation of the network layer for Docker seem to be supporting UDP multicasting. It is called Weave Net Docker Network Plugin.
A possible (still not tested) workaround could be to deploy a special LCM Docker
container. Such container would be based on the base LCM image defined above, but
it will also have an entrypoint script that deploys an LCM tunnel with the server
listening on the port XXXX. At his point the Mac host could run the LCM tunnel
client and receive/send messages transparently.
I'm still not sure whether the Docker bridged network between two or more
containers on Mac supports multicast (this should be tested).
Regardless of this issue, the workaround should work nicely when there is only
one LCM container running on a Mac host. In this case, the same LCM container
would deploy the tunnel.