Communicate to roscore from outside the cluster

[diegoferigo]

This repository contains a simple setup to get ROS running in a kubernetes cluster. If all ROS nodes are deployed within the same cluster, headless services would suffice to connect all their pods.

However, external communication is not that straightforward and should be further investigated. I'm not even sure if it is actually possible to have an external ROS node that communicates with both the roscore and other nodes running within the cluster.

My initial attempts using LoadBalancer services all failed. It would be great if anyone with more kubernetes knowledge is willing to investigate more this use-case and report their results. Existing solutions (as rdbox-intec/rdbox) use a dedicated VPN connection, but despite it is a valid solution, it would be ideal obtaining a setup that only uses kubernetes networking.

[codytrey]

Would using MetalLB in layer 2 mode to expose the services work? (At least for on prem cluster communicating to on prem robots that aren't in the cluster)

[diegoferigo]

I'm not a networking nor a kubernetes expert. I didn't know MetalLB and without any hands-on experience it's hard to tell if it can be a solution. Thanks for reporting, keep me updated if you have some luck and solve this longstanding limitation :) This repo is a weekend exploration and I'm not currently working on it. However, I'm quite curious to see any workaround 😉

[marcoshuck]

There are two workarounds that I'd suggest following for development environments:

• Use minikube and create a tunnel from the kubernetes cluster to localhost with a LoadBalancer. https://minikube.sigs.k8s.io/docs/handbook/accessing/#using-minikube-tunnel
• Consider using NodePort instead of using a LoadBalancer.

[diegoferigo]

Thanks @marcoshuck for chiming in and listing these suggestions! Hopefully it will be helpful for people coming to this issue.