feat(onboarding): early exit conditions in lib-injection

[ZStriker19]

This pull request adds "guardrails" to the "library injection" process. These are early exit conditions from the instrumentation process intended to avoid sending any traces when undefined behavior is likely. The code makes this determination on the basis of software versions present in the application environment, both of Python packages and the Python runtime itself.

The biggest risk here is that instrumentation is disabled when it's not intended to be. I think existing tests in tests/lib-injection cover this pretty well. There's a new test added that verifies instrumentation was cancelled when an unsupported package version is present.

Contains changes from #9418
Related RFC: "[RFC] One Step Guardrails"

Checklist

• minimum package version checks
• Testing
• replace envvars with inject_force
• figure out what to use instead of pkg_resources
• replace local file path with DD_TELEMETRY_FORWARDER_PATH
• Change(s) are motivated and described in the PR description
• Testing strategy is described if automated tests are not included in the PR
• Risks are described (performance impact, potential for breakage, maintainability)
• Change is maintainable (easy to change, telemetry, documentation)
• Library release note guidelines are followed or label changelog/no-changelog is set
• Documentation is included (in-code, generated user docs, public corp docs)
• Backport labels are set (if applicable)
• If this PR changes the public interface, I've notified @DataDog/apm-tees.

Reviewer Checklist

• Title is accurate
• All changes are related to the pull request's stated goal
• Description motivates each change
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Change is maintainable (easy to change, telemetry, documentation)
• Release note makes sense to a user of the library
• Author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: zachg/guardrails_poc
Commit report: 40a4449
Test service: dd-trace-py

✅ 0 Failed, 115914 Passed, 59925 Skipped, 2h 49m 50.84s Total duration (6h 10m 30.05s time saved)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 10.27%. Comparing base (cd92beb) to head (2e80831).
Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #9323       +/-   ##
===========================================
- Coverage   75.89%   10.27%   -65.62%     
===========================================
  Files        1315     1285       -30     
  Lines      124966   123127     -1839     
===========================================
- Hits        94837    12650    -82187     
- Misses      30129   110477    +80348     

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[pr-commenter]

Benchmarks

Benchmark execution time: 2024-06-11 14:03:03

Comparing candidate commit 43bdbc3 in PR branch zachg/guardrails_poc with baseline commit 6a72268 in branch main.

Found 1 performance improvements and 0 performance regressions! Performance is the same for 220 metrics, 9 unstable metrics.

scenario:otelspan-start

• 🟩 max_rss_usage [-6.009MB; -5.942MB] or [-13.137%; -12.991%]

[github-actions]

The backport to 2.9 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-2.9 2.9
# Navigate to the new working tree
cd .worktrees/backport-2.9
# Create a new branch
git switch --create backport-9323-to-2.9
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 0c38e09db92cceedc8affff4a217357fc2a1bcac
# Push it to GitHub
git push --set-upstream origin backport-9323-to-2.9
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-2.9

Then, create a pull request where the base branch is 2.9 and the compare/head branch is backport-9323-to-2.9.