fix(remoteconfig): fix remoteconfig when flare data in payload [backport 2.8]

[github-actions]

Backport 69f91ee from #9196 to 2.8.

Remote config was broken entirely due to the addition of tracer flare data in the config sent from the agent. Example incoming RC config:

data = {'metadata': [{'id': 'configuration_order', 'product_name': 'AGENT_CONFIG', 'sha256_hash': 'ddfc2c7b5ee1710aa915edfccd8a0d452784d946cebae0554485b5c0539a9e2c', 'length': 198, 'tuf_version': 2, 'apply_state': 2, 'apply_error': None}, {'id': 'f6c80fdcc00b702c54ff6ae5ff2ac7f16d9afef109bdf53ee990376455301ab2', 'product_name': 'APM_TRACING', 'sha256_hash': '098cb5a0d27fce648cdd4c6e686038282b64ffee7f42b7238a78552c91948d11', 'length': 616, 'tuf_version': 3, 'apply_state': 2, 'apply_error': None}], 'config': [{'internal_order': ['flare-log-level.trace', 'flare-log-level.debug', 'flare-log-level.info', 'flare-log-level.warn', 'flare-log-level.error', 'flare-log-level.critical', 'flare-log-level.off'], 'order': []}, {'id': 'f6c80fdcc00b702c54ff6ae5ff2ac7f16d9afef109bdf53ee990376455301ab2', 'revision': 1715109076236, 'schema_version': 'v1.0.0', 'action': 'enable', 'lib_config': {'library_language': 'all', 'library_version': 'latest', 'service_name': 'zachs-python-app', 'env': 'zachariah', 'tracing_enabled': True, 'dynamic_sampling_enabled': False, 'tracing_tags': ['rc:works'], 'tracing_sampling_rules': [{'service': 'zachs-python-app', 'provenance': 'customer', 'resource': 'GET /', 'sample_rate': 0.01}, {'service': 'zachs-python-app', 'provenance': 'customer', 'resource': '', 'sample_rate': 1}]}, 'service_target': {'service': 'zachs-python-app', 'env': 'zachariah'}}], 'shared_data_counter': 1}

The python tracer’s implementation of pulling RC rules was brittle and relied upon data["config"][0] always having the lib_config dict. However, with tracer flares it seems the agent sometimes sends the payload with the flare info in that 0 position in the list, so instead we need to sometimes grab data["config"][1] .

Checklist

• 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: backport-9196-to-2.8
Commit report: 3442e80
Test service: dd-trace-py

✅ 0 Failed, 152891 Passed, 19504 Skipped, 10h 47m 19.53s Total duration (1h 55m 27.93s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-05-09 13:53:43

Comparing candidate commit 3442e80 in PR branch backport-9196-to-2.8 with baseline commit b93d994 in branch 2.8.

Found 15 performance improvements and 10 performance regressions! Performance is the same for 176 metrics, 9 unstable metrics.

scenario:coreapiscenario-core_dispatch_with_results_listeners_and_all_listeners

• 🟩 max_rss_usage [-722.456KB; -677.147KB] or [-3.279%; -3.073%]

scenario:coreapiscenario-core_dispatch_with_results_no_listeners

• 🟥 max_rss_usage [+645.014KB; +699.703KB] or [+3.024%; +3.280%]

scenario:coreapiscenario-get_item_missing

• 🟩 max_rss_usage [-718.511KB; -670.442KB] or [-3.264%; -3.046%]

scenario:coreapiscenario-set_item

• 🟩 max_rss_usage [-705.181KB; -438.832KB] or [-3.222%; -2.005%]

scenario:httppropagationextract-b3_single_headers

• 🟥 max_rss_usage [+703.092KB; +749.350KB] or [+3.306%; +3.523%]

scenario:httppropagationextract-full_t_id_datadog_headers

• 🟥 max_rss_usage [+1.105MB; +1.156MB] or [+5.299%; +5.546%]

scenario:httppropagationextract-invalid_trace_id_header

• 🟩 max_rss_usage [-763.280KB; -507.299KB] or [-3.487%; -2.318%]

scenario:httppropagationextract-none_propagation_style

• 🟥 max_rss_usage [+648.178KB; +707.598KB] or [+3.045%; +3.324%]

scenario:httppropagationextract-tracecontext_headers

• 🟥 max_rss_usage [+702.454KB; +756.951KB] or [+3.300%; +3.556%]

scenario:httppropagationextract-valid_headers_all

• 🟩 max_rss_usage [-719.691KB; -667.215KB] or [-3.276%; -3.038%]

scenario:httppropagationextract-wsgi_invalid_trace_id_header

• 🟩 max_rss_usage [-703.377KB; -476.680KB] or [-3.218%; -2.181%]

scenario:httppropagationextract-wsgi_large_header_no_matches

• 🟥 max_rss_usage [+886.161KB; +964.003KB] or [+4.208%; +4.578%]

scenario:httppropagationextract-wsgi_medium_header_no_matches

• 🟥 max_rss_usage [+878.727KB; +968.159KB] or [+4.175%; +4.600%]

scenario:httppropagationextract-wsgi_medium_valid_headers_all

• 🟥 max_rss_usage [+494.798KB; +728.677KB] or [+2.324%; +3.423%]

scenario:httppropagationinject-ids_only

• 🟥 max_rss_usage [+529.459KB; +686.644KB] or [+2.481%; +3.217%]

scenario:httppropagationinject-with_dd_origin

• 🟥 max_rss_usage [+815.075KB; +872.886KB] or [+3.868%; +4.142%]

scenario:httppropagationinject-with_tags_max_size

• 🟩 max_rss_usage [-709.029KB; -602.101KB] or [-3.229%; -2.742%]

scenario:sethttpmeta-all-enabled

• 🟩 max_rss_usage [-719.732KB; -481.215KB] or [-3.252%; -2.174%]

scenario:sethttpmeta-no-useragentvariant

• 🟩 max_rss_usage [-778.672KB; -455.043KB] or [-3.532%; -2.064%]

scenario:sethttpmeta-useragentvariant_exists_2

• 🟩 max_rss_usage [-701.276KB; -647.537KB] or [-3.151%; -2.909%]

scenario:sethttpmeta-useragentvariant_exists_3

• 🟩 max_rss_usage [-750.764KB; -696.762KB] or [-3.369%; -3.127%]

scenario:span-start-finish

• 🟩 max_rss_usage [-705.678KB; -564.082KB] or [-3.209%; -2.565%]

scenario:tracer-large

• 🟩 max_rss_usage [-775.838KB; -705.276KB] or [-3.357%; -3.052%]

scenario:tracer-medium

• 🟩 max_rss_usage [-802.043KB; -725.355KB] or [-3.627%; -3.280%]

scenario:tracer-small

• 🟩 max_rss_usage [-763.788KB; -684.558KB] or [-3.447%; -3.089%]