zlacker

Do either of them work for container-to-container traffic?

Imagine container A which exposes tightly-coupled services X and Y. Container B should be able to access only X, container C should be able to accesd only Y.

For some reason there just isn't a convenient way to do this with Docker or Podman. Last time I looked into it, it required having to manually juggle the IP addressed assigned to the container and having the service explicitly bind to it - which is just needlessly complicated. Can firewalls solve this?

>>crote+(OP)
I can't answer your question about Docker or Podman, but in Kubernetes there is the NetworkPolicy API which is designed for exactly this use-case. I'm sure it uses Linux native tooling (iptables, nftables, etc) under the hood, so it's at least within the real of feasible that those tools can be used for this purpose.