powerpc support

[lukasheinrich]

Hi,

would sarus be expected to work on ppc64 machines, such as IBM HPCs? e.g. this docker image: ppc64le/centos

Thanks,
Lukas

[Madeeks]

Hi Lukas,

we have not built or tested Sarus outside of Linux x86-64, which is also the target architecture of the standalone archive we distribute on GitHub releases.
In any case, the Sarus code does not contain x86-specific parts, and is pretty much architecture-agnostic, so it could probably work on Power architectures as well if compiled from source.
The hardest part may be building the dependencies (e.g. cpprestsdk or runc): https://sarus.readthedocs.io/en/stable/install/requirements.html
For reference, here is also the documentation about building Sarus from source: https://sarus.readthedocs.io/en/stable/install/installation.html#installing-from-source (edited)
Cheers,

Alberto

[lukasheinrich]

runc should not be the problem, since I know containerd runs on power which should also use runc

this suggests cpprestsdk should also compile on power
microsoft/cpprestsdk#576

maybe it's worth looking into. Just to clarify, sarus is both daemon- and root-less?

Lukas

[Madeeks]

Sarus is indeed daemon-less, but requires root privileges to run containers, as detailed here.
The main reason for this is to allow mounting the container image as a loop device, preventing metadata thrashing when many containers access the same image on a parallel filesystem (for reference, see point 1. here).
Note that Sarus tries to be responsible with this power, performing several security checks to safekeep itself and the host system.

[lukasheinrich]

given that runc can run rootless, would there be a possible mode to run in rootless mode (say if we have an unpacked flat filesystem as a rootfs)

[Madeeks]

It's not completely clear to me what's the use case you have in mind, could you please provide some more details?

Regarding the mount of the rootfs, there is an ongoing effort of benchmarking Squashfuse to understand the performance implications of such feature when applied to HPC deployments.

[haampie]

@lukasheinrich if you mean rootless in the sense of user namespaces / user mapping (being root in the container, but without being root outside of it), I've tried it here: #15 and it seems to work more or less, but cgroups are still an issue.

[taliaga]

Closing issue because the question was answered and there is no clear next action to do. Feel free to reopen with further clarifications if needed.