Configure shared memory size explicitly in kubernetes

[englehardt]

From #28:

As explored in openwpm/OpenWPM#255, newer versions of Firefox will often crash due to insufficient shared memory. This issue wasn't present in the Firefox 52 branch because we used to set browser.tabs.remote.autostart to False, which disables SHM usage by disabling e10s.

When running a Docker container, the shared memory size can be increased by adding the argument --shm-size=2g. Unfortunately kubernetes doesn't yet support setting the shared memory size (see: kubernetes/kubernetes#28272), nor does it support passing arguments to docker. The current fix is a workaround copied from kubernetes/kubernetes#28272 (comment).

We should migrate from mounting an in-memory folder in the shared memory location to actually bumping the real shared memory size once kubernetes supports it. I'm opening this issue as a reminder.