WIP: feat(otel): add support for opentelemetry logs

[rachelyangdog]

Description

Adds OpenTelemetry logs support to dd-trace-php, gated behind a new DD_LOGS_OTEL_ENABLED configuration flag.

New config flag: DD_LOGS_OTEL_ENABLED (default: false) enables OTel log collection and OTLP export. When enabled, Datadog's own log injection is suppressed so the two pipelines don't conflict.

• CompositeResolver now handles logs signal endpoints and protocols alongside the existing metrics support. Endpoint/protocol resolution is refactored from metrics-specific to signal-agnostic

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.78%. Comparing base (fd1ba67) to head (5e7dc32).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3748      +/-   ##
==========================================
- Coverage   68.85%   68.78%   -0.08%     
==========================================
  Files         166      166              
  Lines       19015    19015              
  Branches     1792     1792              
==========================================
- Hits        13093    13079      -14     
- Misses       5111     5124      +13     
- Partials      811      812       +1     

Flag	Coverage Δ
helper-rust-integration	78.82% <ø> (ø)
helper-rust-unit	49.36% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.
see 3 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fd1ba67...5e7dc32. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[datadog-prod-us1-5]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 60.64% (-0.04%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 5e7dc32 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

[pr-commenter]

Benchmarks [ tracer ]

Benchmark execution time: 2026-03-28 22:24:11

Comparing candidate commit 5e7dc32 in PR branch rachel.yang/otel-logs with baseline commit fd1ba67 in branch master.

Found 2 performance improvements and 7 performance regressions! Performance is the same for 181 metrics, 4 unstable metrics.

scenario:ContextPropagationBench/benchExtractHeaders128Bit-opcache

• 🟩 execution_time [-755.236ns; -720.764ns] or [-47.261%; -45.104%]

scenario:ContextPropagationBench/benchExtractTraceContext128Bit-opcache

• 🟩 execution_time [-918.899ns; -731.101ns] or [-34.262%; -27.260%]

scenario:LogsInjectionBench/benchLogsInfoInjection-opcache

• 🟥 execution_time [+339.827ns; +652.973ns] or [+4.074%; +7.829%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization-opcache

• 🟥 execution_time [+7.440µs; +8.400µs] or [+7.240%; +8.174%]

scenario:SamplingRuleMatchingBench/benchRegexMatching1

• 🟥 execution_time [+53.482ns; +128.718ns] or [+3.695%; +8.892%]

scenario:SamplingRuleMatchingBench/benchRegexMatching2

• 🟥 execution_time [+57.356ns; +118.044ns] or [+3.908%; +8.043%]

scenario:SamplingRuleMatchingBench/benchRegexMatching3

• 🟥 execution_time [+67.305ns; +146.495ns] or [+4.564%; +9.933%]

scenario:SamplingRuleMatchingBench/benchRegexMatching3-opcache

• 🟥 execution_time [+48.383ns; +120.017ns] or [+3.084%; +7.649%]

scenario:SamplingRuleMatchingBench/benchRegexMatching4

• 🟥 execution_time [+67.191ns; +160.409ns] or [+4.589%; +10.956%]