Make linux_hostinfo platform optional

[jemag]

Motivation

After discussion in the following issue: falcosecurity/charts#754 , what I could gather is that the new linux_hostinfo platform provides additional information to plugins should they need it.

However, Falco being a fairly general tool to process event streams and apply rules to them, plugins can be made to target event streams where the hostinfo of where Falco is running is irrelevant, or of very little concern.

I think it would be great if this could be optional, so that, when deployed to Kubernetes, hostPath is not required.

Feature
Make the new linux_hostinfo platform optional so that it can be turned off and hostPath isn't required.

Alternatives
Keep hostPath even though it is not required by plugin.

[FedeDP]

Hi! Thanks for opening this issue!
I'd move this to Falco since libs is already agnostic, the platform gets requested by Falco when opening plugins: https://github.com/falcosecurity/falco/blob/master/userspace/falco/app/actions/helpers_inspector.cpp#L64

Indeed, we could add a Falco config key to disable the default behavior of adding hostinfo to the plugin run, wdyt?

[FedeDP]

/milestone 0.40.0

[jemag]

Indeed, we could add a Falco config key to disable the default behavior of adding hostinfo to the plugin run, wdyt?

That would be great!

[FedeDP]

Opened #3412 to implement the new config key!