(fix) malformed YAML in SLES 16.1 product files

[mvidner]

Problem

• agama-web-server.service fails to start, in daily CI run: https://github.com/agama-project/agama/actions/runs/24238863269/job/70768224867
• mistake in editing a product file, in Install by default the enhanced_base pattern for immutable mode  #3356
• schema validity is not even a question, it simply does not deserialize

Solution

• fix the syntax
• .changes file

Testing

• Tested manually
• Added a new unit test to catch this sooner

Screenshots

No

Documentation

Do we need more docs? No, just more tests to catch it before the PR is merged.

[lslezak]

Let's use yq for YAML validation.

[lslezak]

I'd avoid downloading our special Docker image if really not needed. OBS is sometimes slow or download fails. This causes false alarms and you have to restart the CI, sometimes even several restarts are needed.

In this case we could simply use the yq tool (similar to jq but for YAML). It is already preinstalled in the default Ubuntu image in the GitHub actions. This will make the CI run also much faster.

Simply running yq should be enough:

> yq sles_161.yaml 
Error: bad file 'sles_161.yaml': yaml: line 349: mapping values are not allowed in this context

It reports the same failure as Ruby YAML parser:

> ruby -ryaml -e 'Dir.glob("*.{yml,yaml}").sort.each { |fn| puts fn; YAML.safe_load(File.read(fn)) }; puts "OK"'
kalpa.yaml
leap_161.yaml
leap_micro_62.yaml
microos.yaml
sles_161.yaml
Traceback (most recent call last):
	6: from -e:1:in `<main>'
	5: from -e:1:in `each'
	4: from -e:1:in `block in <main>'
	3: from /usr/lib64/ruby/2.5.0/psych.rb:314:in `safe_load'
	2: from /usr/lib64/ruby/2.5.0/psych.rb:350:in `parse'
	1: from /usr/lib64/ruby/2.5.0/psych.rb:402:in `parse_stream'
/usr/lib64/ruby/2.5.0/psych.rb:402:in `parse': (<unknown>): mapping values are not allowed in this context at line 349 column 19 (Psych::SyntaxError)

I'd fallback to Ruby only when yq is not installed.

[lslezak]

BTW there is also the yamllint tool pre-installed. But it looks too strict, IMHO yq is enough:

> yamllint sles_161.yaml 
sles_161.yaml
  1:1       warning  missing document start "---"  (document-start)
  24:81     error    line too long (83 > 80 characters)  (line-length)
  29:81     error    line too long (82 > 80 characters)  (line-length)
  39:81     error    line too long (84 > 80 characters)  (line-length)
  50:81     error    line too long (83 > 80 characters)  (line-length)
  63:81     error    line too long (84 > 80 characters)  (line-length)
  70:81     error    line too long (81 > 80 characters)  (line-length)
  75:81     error    line too long (83 > 80 characters)  (line-length)
  88:81     error    line too long (84 > 80 characters)  (line-length)
  92:81     error    line too long (81 > 80 characters)  (line-length)
  184:25    warning  too few spaces before comment  (comments)
  210:81    error    line too long (92 > 80 characters)  (line-length)
  212:35    warning  too few spaces before comment  (comments)
  212:81    error    line too long (89 > 80 characters)  (line-length)
  228:81    error    line too long (81 > 80 characters)  (line-length)
  261:81    error    line too long (107 > 80 characters)  (line-length)
  335:81    error    line too long (81 > 80 characters)  (line-length)
  349:19    error    syntax error: mapping values are not allowed here (syntax)
  370:81    error    line too long (107 > 80 characters)  (line-length)

[mvidner]

@lslezak the Ubuntu runner has Ruby, so I implemented the yq check and then reverted it. It's simpler with Ruby :)

[lslezak]

LGTM