add arch filter class to unify architectures specification

[jreidinger]

Problem

There are multiple places where we need to specify in text form condition to apply only to certain hardware architectures and it is not unified so far.

Related to https://trello.com/c/C3apZtHv/3231-d-installer-support-for-dynamic-configuration

Solution

Unified solution is based on specification of subvolume handling https://github.com/yast/yast-storage-ng/blob/master/src/lib/y2storage/subvol_specification.rb#L119

There are some improvements to it:

• allowing white spaces
• case insensitivity
• support for 'all' method
• raise exception when invalid element of string is used

Testing

• new unit tests are added

Open Questions

There is one more place which define architecture filtering - in workflows https://github.com/yast/yast-yast2/blob/master/library/control/src/modules/WorkflowManager.rb#L209 Question is if we want to use filter also here? If so, then we need to support all keyword to match everything and of course adapt that code.

[coveralls]

Coverage increased (+0.06%) to 41.778% when pulling 92bd53d2d839dd9659942989da1ab9d2694ed800 on arch_filter into aa302a71e3fb71c23e80b4cc49799ce98b180f46 on master.

[ancorgs]

It generally looks good. Just two notes:

• Documentation is hard to read. Fortunately examples help. Maybe we could invoke @mvidner here for some help on generating understandable (English) texts.
• I agree having some way to specify all architectures would make sense. Not only to support the workflow manager but also for cases in which you only want to exclude a particular case. As documented !ppc64,!aarch64 always returns false so there is no way to express "always except for ppc64 and aarch64". That would be possible with something like this *,!ppc64,!aarch64 or any,!ppc64,!aarch64.

[mvidner]

The main question is: WHO will write the architecture specifications/filters, and where.

I'm asking because currently we delegate the elementary matchers to the implementation of Yast::Arch. That's fine if ArchFilter is internal. But as soon as we tell release managers or even customers to use it, we will have to list the individual recognized architectures authoritatively, and preferably in one place.

[jreidinger]

@mvidner well, I expect it will be as usual us who will write it, but it is also used in control.xml and also d-installer.yml can be modified by users for having their own modified installer. But for list it is always hard to keep it in sync :( Even now in control.xml documentation we do not write all possible values - https://github.com/yast/yast-installation/blob/master/doc/control-file.md#the-volumes-subsection

[mvidner]

Even now in control.xml documentation we do not write all possible values - https://github.com/yast/yast-installation/blob/master/doc/control-file.md#the-volumes-subsection

OK. Now that I've read that file, I'm actually worried about the meaning of the comma , operator:

Normally, architectures are combined with logical OR, i.e.

<archs>i386,x86_64</archs>

means "if architecture i386 or x86_64". If the current architecture is an architecture that was excluded with "!", that subvolume is not used no matter what other architectures are specified that might also apply.

[mvidner]

OK, let's borrow naming from logic: (see DNF)

• an atom is a call to some boolean method in Arch, (documenting the supported list and semantics is WIP)
• a literal is an atom or its negation via !
• a conjunction (logical and) is a list of literals joined with &
• a disjunction (logical or) is a list of literals joined with |
• a guessjunction :rofl: is a list of literals joined with ,: if it contains a negation ! it is a conjunction, otherwise a disjunction

IMHO this captures the existing usages of ppc,!board_powernv (where, importantly, board_powernv is a subset of ppc) and i386,x86_64

TODO: does this work with all?

[mvidner]

functions (atoms) as of today https://github.com/yast/yast-yast2/blob/aa302a71e3fb71c23e80b4cc49799ce98b180f46/library/general/src/modules/Arch.rb

• architecture
  • i386
  • sparc32
  • sparc64
  • sparc (=sparc32|sparc64)
  • ppc32
  • ppc64
  • ppc (=ppc32|ppc64)
  • alpha
  • s390_32
  • s390_64
  • s390 (=s390_32|s390_64)
  • ia64
  • x86_64
  • arm
  • aarch64
  • riscv64
• ppc boards
  • board_mac
  • board_mac_new
  • board_mac_old
  • board_chrp
  • board_powernv
  • board_iseries
  • board_prep
  • board_pegasos
• not ppc
  • board_wintel
• non-arch checks
  • has_pcmcia
  • is_laptop
  • is_virtual
  • is_uml
  • is_xen
  • is_xen0
  • is_xenU
  • paravirtualized_xen_guest? ; note '?'
  • is_kvm
  • is_zkvm
  • is_wsl
• smp
  • has_smp

[yast-bot]

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[yast-bot]

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