Base the ops-toolbelt on the `alpine` base

[mimiteto]

What would you like to be added:
Let's base the toolbelt on alpine. This way we get the smaller base image.
We already have a way to install packages from builds if there is no such package in the alpine repos.

Why is this needed:
That way we get a base that is vastly more popular and there is a higher chance the image layers are already present on the node where we need a toolbelt deployed, hence we may get a faster startup.

[zkdev]

once Gardenlinux usage was dismantled, please make sure to also remove the ocm reference - thanks

[pnpavlov]

Hey! I would recommend to carefully asses the pros and cons of this change.

Yes, Alpine is like 10MB and Garden Linux 110Mb. I would question the real world impact on saving 100MB on machines with 10Gbps+ connectivity.

Imho the main pros & cons analysis to have is:

• having smaller base
  against

• less packages pre-built in the alpine vs debian ecosystem (does that matter to you ?)
• the ability to be vip customer, meaning you can always get help from the garden linux team door regarding questions or change requests or package needs.
• not sure what would be the impact in case the container is used also by the wider ecosystem or other teams around you.

Still, no matter what you decide to use as base, please consider evaluating auto-update of the base image e.g. with the renovate bot or alternative you prefer.