fix(datadog_filter): make wildcard regexes match across newlines#1855
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fix(datadog_filter): make wildcard regexes match across newlines#1855Stunned1 wants to merge 3 commits into
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Wildcard patterns compiled by wildcard_regex produced ^...$ regexes where . cannot match \n, so any value with a trailing or embedded newline never matched (e.g. query 'field:*' on value "hello\n"). word_regex had the same defect for wildcards spanning newlines. Enable the (?s) DOTALL flag so *-derived .* matches any character, including newlines. Non-wildcard parts of the pattern are escaped literals and are unaffected. Fixes vectordotdev#1824
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Summary
wildcard_regexcompiled Datadog wildcard queries into^...$patterns where.cannot match\nand$anchors at the absolute end of the string. As a result, queries likefield:*orfield:*some*silently failed to match any value with a trailing newline (common in Lambda, container stdout, and other line-delimited sources) or with embedded newlines.This applies the fix proposed in #1824: enable the
(?s)(DOTALL) flag so the.*derived from*matches any character, including\n. Everything else in the generated pattern isregex::escaped literal text, so(?s)only affects the wildcard segments. The issue's alternative suggestion (^{}\n?$) was evaluated and rejected: it does not fix embedded newlines (field:*would still fail on multi-line values) and it wrongly loosens matching (field:*someand even exact patterns would match values with a trailing newline).The same flag is applied to
word_regex(default-field queries), which had the same defect in a different form: a*-derived.*could not span a newline, sofoo*barfailed to match"foo\nbar". The trailing-newline symptom from the issue does not affectword_regex(it has no^...$anchors), but wildcard-across-newline does.Change Type
Is this a breaking change?
How did you test this PR?
src/datadog/filter/regex.rscovering trailing newlines, embedded newlines, and no-over-match cases (*somemust still not match"here is some\n"; exact patterns are unchanged).match_datadog_querytests exercising the real query paths (@a:*,@a:*some*, multi-line values, default-fieldfoo*bar)../scripts/checks.sh: format_check, clippy (-D warnings, all features, all targets), tests (workspace), and vrl_tests all pass locally.Does this PR include user facing changes?
our guidelines.
Checklist
run
dd-rust-license-tool writeand commihere.References