Log the framework-provided exceptions with no stacktraces

[nolar]

Do not print stacktraces of internal temporary/permanent errors, just log the message.

Issue : #16

Description

Shorter logging

The internal temporary and permanent errors are special exceptions to control the framework's flow of handler execution: either to retry it, or to stop trying — regardless of the global mode on arbitrary error handling (in the assumption that retry_on_error will be exposed to the users some day).

They are supposed to already contain the information needed to identify the cause of the problem. Stacktraces are not needed (they are needed only for the unexpected errors with unclear origin).

Instead, stacktraces of these special errors make it difficult to identify when an actual unexpected errors happens (by visually or automatically looking for stacktraces in the logs).

Therefore, the stacktraces are removed for these special error — and only for them. All unexpected arbitrary exceptions still have stacktraces as before.

Exceptions renamed

As a little refactoring, the exception classes are renamed for clarify, and to remove the mentions of "handler" from their names:

• kopf.HandlerRetryError --> kopf.TemporaryError
• kopf.HandlerFatalError --> kopf.PermanentError

The old names are kept as the aliases (so they still can be used as kopf.HandlerRetryError/kopf.HandlerFatalError in try-except clauses or any other places).

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor/improvements

Review

• Tests
• Documentation

[zincr]

🤖 zincr found 0 problems , 0 warnings

✅ Large Commits
✅ Approvals
✅ Specification
✅ Dependency Licensing

[zincr]

🤖 zincr found 1 problem , 0 warnings

❌ Approvals
✅ Large Commits
✅ Specification
✅ Dependency Licensing

Details on how to resolve are provided below

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Approvals

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Not enough people have approved this pull request - please ensure that 1 additional user, who have not contributed to this pull request approve the changes.

• ✅ Approved by PR author @nolar
• ❌ 1 additional approval needed
   

[codecov-io]

Codecov Report

Merging #159 into master will increase coverage by 0.05%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #159      +/-   ##
==========================================
+ Coverage   82.76%   82.82%   +0.05%     
==========================================
  Files          32       32              
  Lines        1596     1601       +5     
  Branches      231      232       +1     
==========================================
+ Hits         1321     1326       +5     
  Misses        230      230              
  Partials       45       45

Impacted Files	Coverage Δ
kopf/reactor/handling.py	85.85% <100%> (+0.21%)	⬆️
kopf/__init__.py	100% <100%> (ø)	⬆️