Stage option specificity

[supakeen]

Let's have chat about two osbuild PRs from a philosophy standpoint:

osbuild/osbuild#1506
osbuild/osbuild#1507

Both of these add support for being more 'free' with your stage options; instead of defining the exact kernels we regenerate all kernels, and instead of defining exact paths we define globs for the copy.

I see no technical problem with those approaches as they will still always do the same given the same input tree; however for debugging when reading manifests it's definitely an implicitness I don't like.

Both of these PRs also seem to be geared towards making manual manifest writing easier; but I believe that's something that we discourage in general (?).

For the kernel shenanigans we do have some osbuild-mpp related things that might be able to do this based on the resolved package set however for the glob copies we don't, as those require use to actually construct the tree that is being copied on/from.

[achilleas-k]

... for debugging when reading manifests it's definitely an implicitness I don't like.

Both of these PRs also seem to be geared towards making manual manifest writing easier; but I believe that's something that we discourage in general.

This sums up mostly how I feel about this.
I think also, historically, the explicitness of manifests has been a good way to catch and investigate changes. For example, given a set of packages to install, the resulting tree is (or should be) known. A copy stage that globs /some/path/*.conf to put some configs in different places will work even when that tree changes and that change shouldn't be something that goes unnoticed.

Explicitness of stages makes them predictable and very "standalone" units of operation. I feel it's hard to explain the importance of this sometimes, and I suspect it depends on how often one has had to troubleshoot a build failure from a manifest they didn't themselves create.

[bcl]

Just another +1 from me. I also think that allowing these will lead to other less explicit changes down the road, and will also make it harder to argue against them :)