VM-like masking of total memory and CPUs at `/proc`

I'm not sure if this is out-of-scope or not, but yet I'm opening this issue for discussing.

When we run:

$ docker run --rm --memory 500Mi ubuntu free -h
              total        used        free      shared  buff/cache   available
Mem:          7.7Gi       2.6Gi       186Mi       4.1Gi       4.9Gi       839Mi
Swap:         2.0Gi       1.0Gi       1.0Gi

It shows the total memory of the host machine despite of the --memory constraint. The same happens when using sysbox-runc. This is intended.

The thing is: as Sysbox claims to transform containers to VM-like ones, would it be possible to allow Sysbox to enforce the total memory which the container will recognize just like normal VMs?

By using --memory today, if my containers trespass the limit, they gets killed. Ideally, I would like the containers not to recognize the total memory, so they handle the available memory the way they want without being killed by the daemon. In a CI/CD build pool it's a very desired feature, as I can set a given number of resources for each build and I do not have control over what happens in such builds.

The same rationale and use case applies for CPUs as well.

Start by reviewing the /proc views of total memory and CPUs exposed under Docker --memory constraints, and compare them with the behavior of sysbox-runc. Define the intended masking semantics for memory and CPU resources, including CI/CD use cases, before locating the relevant Sysbox runtime entry points. Done means the container reports the configured resources without breaking enforcement or existing VM-like behavior.