appsec: blocking unavailable

[e-n-0]

What does this PR do?

Disable sending the blocking capability if the tracer is running in a context when blocking is not possible.

Motivation

When running the GCP Service Extension in observability mode, it's not possible to block but we still want to get remote rules from RC (monitoring only).

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: flavien/v2/blocking-unavailable
Commit report: de2c5d4
Test service: dd-trace-go

❌ 1 Failed (1 Known Flaky), 4383 Passed, 61 Skipped, 3m 43.65s Total Time

❌ Failed Tests (1)

• TestIntegrationEnabled - github.com/DataDog/dd-trace-go/v2/ddtrace/tracer - ❄️ Known flaky - Details

  Expand for error

   Failed
   
   === RUN   TestIntegrationEnabled
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/99designs/gqlgen
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/IBM/sarama
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/Shopify/sarama
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/aws/aws-sdk-go
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/aws/aws-sdk-go-v2
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/bradfitz/gomemcache
       option_test.go:370: /home/runner/work/dd-trace-go/dd-trace-go/contrib/cloud.google.com/go/pubsub.v1
   ...
  

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-03-13 18:18:22

Comparing candidate commit b26eda9 in PR branch flavien/v2/blocking-unavailable with baseline commit 135e802 in branch main.

Some scenarios are present only in baseline or only in candidate runs. If you didn't create or remove some scenarios in your branch, this maybe a sign of crashed benchmarks 💥💥💥
Check Gitlab CI job log to find if any benchmark has crashed.

Scenarios present only in baseline:

• BenchmarkSampleWAFContext-24
• BenchmarkStartRequestSpan-24

Found 0 performance improvements and 6 performance regressions! Performance is the same for 48 metrics, 2 unstable metrics.

scenario:BenchmarkHttpServeTrace-24

• 🟥 allocations [+3; +3] or [+3.297%; +3.297%]
• 🟥 execution_time [+1.094µs; +1.234µs] or [+6.096%; +6.872%]

scenario:BenchmarkSingleSpanRetention/no-rules-24

• 🟥 execution_time [+5.699µs; +6.838µs] or [+2.243%; +2.691%]

scenario:BenchmarkSingleSpanRetention/with-rules/match-all-24

• 🟥 execution_time [+5.542µs; +6.957µs] or [+2.172%; +2.726%]

scenario:BenchmarkSingleSpanRetention/with-rules/match-half-24

• 🟥 execution_time [+6.906µs; +8.225µs] or [+2.705%; +3.221%]

scenario:BenchmarkTracerAddSpans-24

• 🟥 allocated_mem [+57 bytes; +57 bytes] or [+2.456%; +2.456%]