feat(process_tags): add process_tags to tracing payloads

[dubloom]

Description

This PR implements this RFC for the tracing product.

Add process_tags in APM payload. According to the RFC, the tag _dd.tags.process is set in the first first span of each payload.

The set tag are:

• entrypoint.workdir. The working dir name, should be the last path segment.
• entrypoint.name. The entrypoint of the application. It is the the script name. Set to none if php is executed as an executable.
• entrypoint.type. Either script or executable
• entrypoint.basedir. The base dir is the directory where the called executable resides. Should be the last path segment.
• runtime.sapi. The name of the SAPI in which PHP is run.

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[datadog-datadog-prod-us1]

⚠️ Tests

✨ Fix all issues with Cursor

⚠️ Warnings

🧪 1024 Tests failed

    testSearchPhpBinaries from integration.DDTrace\Tests\Integration\PHPInstallerTest (Fix with Cursor)

    testSimplePushAndProcess from laravel-58-test.DDTrace\Tests\Integrations\Laravel\V5_8\QueueTest (Fix with Cursor)

testSimplePushAndProcess from laravel-8x-test.DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest::testSimplePushAndProcess
Test code or tested code printed unexpected output: spanLinksTraceId: 69666e8f00000000c55f2c7bd8b9a6cc
tid: 69666e8f00000000
hexProcessTraceId: c55f2c7bd8b9a6cc
hexProcessSpanId: 093839a093202d86
processTraceId: 14222135058687960780
processSpanId: 664344306863058310

View all

ℹ️ Info

❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 3a8038c | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.01%. Comparing base (2c70c61) to head (3a8038c).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3566   +/-   ##
=======================================
  Coverage   62.01%   62.01%           
=======================================
  Files         140      140           
  Lines       13309    13309           
  Branches     1762     1762           
=======================================
  Hits         8253     8253           
  Misses       4268     4268           
  Partials      788      788           

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[bwoebi]

Suggested change

	process_tag_entry_t* bigger_list = realloc(
	process_tags.tag_list,
	process_tags.capacity * sizeof(process_tag_entry_t)
	);
	process_tag_entry_t* bigger_list = perealloc(
	process_tags.tag_list,
	process_tags.capacity * sizeof(process_tag_entry_t),
	1
	);

Also at other places, use pemalloc(, 1), and pefree(, 1). (They ultimately call system malloc functions, but defer to PHPs handling for OOM.)

[bwoebi]

Then you can remove the if (!bigger_list) completely.

[dubloom]

addressed in 127c555

[bwoebi]

It is known and acknowledged, that for web requests, where multiple web applications are hosted on a single web server, or have multiple entrypoints, the values will always reflect the first request after process start (which may be distinct between different processes of the same webserver in multiprocessing mode - which is e.g. the default for FPM), given that they're collected in first rinit?
If yes, then it's fine.

[dubloom]

addressed in 127c555