Most of the things I described assume you have full control over your host's OS.
For stuff like you mention - you should maybe reconsider not using containers if you're on a pay-per-container platform? They are just a tool, and certainly don't fit every single use-case. Also - paying per container seems like a silly thing to do - since containers can be very short-lived. Resource-based billing would be a better fit - although that could be tricky to measure I guess.
I'm currently toying with IBM bluemix (mostly because they have a relatively big free tier) and they have resource-based billing, but you since can't make containers arbitrarily small and you pay for RAM reserved for a container, it is effectively per container. So even if you only need 1 GB for 30 min every night, you either build something that starts a worker container on schedule or you pay for resources you don't use 98% of the time. I guess other platforms are similar.
But of course, if you can afford to use that in production it probably doesn't matter very much, and you might choose a different platform if it bugs you. Just came to mind because I just was wondering how to split stuff up.
For stuff like you mention - you should maybe reconsider not using containers if you're on a pay-per-container platform? They are just a tool, and certainly don't fit every single use-case. Also - paying per container seems like a silly thing to do - since containers can be very short-lived. Resource-based billing would be a better fit - although that could be tricky to measure I guess.