Fix hiera.yaml write race in the pupmod spec_helper template - #91
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The config-level before(:all) hook rewrites spec/fixtures/hieradata/hiera.yaml with a truncating write before every top-level example group. Under `rake parallel_spec`, every worker runs this hook, and a catalogue compile in another worker that reads hiera.yaml inside the truncate-to-write window sees an empty hiera config and silently compiles without any custom hieradata. This is the confirmed root cause of the fleet-wide random hieradata-not-applied spec failures (ref simp#90) — not the set_hieradata global-state design originally suspected. Reproduced deterministically in pupmod-simp-simplib by rewriting hiera.yaml in a tight loop while running dlookup_spec (simp/pupmod-simp-simplib#362, fixed there by simp/pupmod-simp-simplib#363 with this same change). Write the file atomically instead: write to a PID-suffixed temp file in the same directory and rename it into place. Readers then always see a complete hiera.yaml. The temp file must be in the same directory -- rename(2) is only atomic within a filesystem. Ref simp#90 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Closes #90.
Every
parallel_specworker'sbefore(:all)hook truncate-rewrites the sharedspec/fixtures/hieradata/hiera.yaml; a catalogue compile in another worker during the truncation window sees an empty hiera config and silently drops all custom hieradata. That's the source of the fleet's random hieradata-not-applied spec failures (simp/pupmod-simp-simplib#362, simp/pupmod-simp-rsyslog#211, and the earlier freeradius/simp_options/tftpboot/gnome/ssh/sssd "flakes"). The fix writeshiera.yamlatomically (write to a pid-suffixed tempfile + rename).Validated on simp/pupmod-simp-simplib#363 (merged): the module with the highest observed flake rate, green with the fixed helper.
Rollout, per the usual convention, ships in the same PR: session config
20260820-spec-helper-race.yaml(nowlatest) — a blanketapply_puppet_rolesession, safe again since #42. Because the baseline was just re-asserted fleet-wide, each repo's diff is exactly the atomic-write hunk (verified by a local e2e apply against a real pupmod-simp-aide clone); simplib already carries the fix and will come outunchanged.Rebased onto main (post-#42, so the template base is current); the rendered non-simpkv template is byte-identical to simplib's validated in-repo copy. 215 rspec + 26 BoltSpec examples green; both EPP render branches are valid Ruby.
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