add remote config support for custom tags

[rochdev]

What does this PR do?

Add remote config support for custom tags.

Motivation

So that users can set custom tags through the UI.

Additional Notes

The previous behaviour of merging tags was incorrect and has now been fixed with the tests updated accordingly.

[github-actions]

Overall package size

Self size: 5.78 MB
Deduped: 61.89 MB
No deduping: 62.65 MB

Dependency sizes

name	version	self size	total size
@datadog/native-iast-taint-tracking	1.6.4	16.43 MB	16.44 MB
@datadog/native-appsec	5.0.0	15.16 MB	15.17 MB
@datadog/pprof	4.1.0	9.36 MB	10.21 MB
protobufjs	7.2.5	2.77 MB	6.56 MB
@datadog/native-iast-rewriter	2.2.2	2.29 MB	2.37 MB
@opentelemetry/core	1.14.0	872.87 kB	1.47 MB
@datadog/native-metrics	2.0.0	898.77 kB	1.3 MB
@opentelemetry/api	1.4.1	780.32 kB	780.32 kB
import-in-the-middle	1.4.2	41.4 kB	704.79 kB
pprof-format	2.0.7	588.12 kB	588.12 kB
msgpack-lite	0.1.26	201.16 kB	281.59 kB
opentracing	0.14.7	194.81 kB	194.81 kB
semver	7.5.4	93.4 kB	123.8 kB
@datadog/sketches-js	2.1.0	109.9 kB	109.9 kB
lodash.sortby	4.7.0	75.76 kB	75.76 kB
lru-cache	7.14.0	74.95 kB	74.95 kB
ipaddr.js	2.1.0	60.23 kB	60.23 kB
ignore	5.2.4	51.22 kB	51.22 kB
int64-buffer	0.1.10	49.18 kB	49.18 kB
istanbul-lib-coverage	3.2.0	29.34 kB	29.34 kB
lodash.uniq	4.5.0	25.01 kB	25.01 kB
tlhunter-sorted-set	0.1.0	24.94 kB	24.94 kB
limiter	1.1.5	23.17 kB	23.17 kB
dc-polyfill	0.1.2	22.77 kB	22.77 kB
retry	0.13.1	18.85 kB	18.85 kB
lodash.kebabcase	4.1.1	17.75 kB	17.75 kB
node-abort-controller	3.1.1	16.89 kB	16.89 kB
lodash.pick	4.4.0	16.33 kB	16.33 kB
jest-docblock	29.7.0	8.99 kB	12.76 kB
crypto-randomuuid	1.0.0	11.18 kB	11.18 kB
path-to-regexp	0.1.7	6.78 kB	6.78 kB
koalas	1.0.2	6.47 kB	6.47 kB
methods	1.1.2	5.29 kB	5.29 kB
module-details-from-path	1.0.3	4.47 kB	4.47 kB

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[codecov]

Codecov Report

Attention: 12 lines in your changes are missing coverage. Please review.

Comparison is base (db16b8d) 84.73% compared to head (d6f8681) 84.66%.
Report is 2 commits behind head on master.

Files	Patch %	Lines
packages/dd-trace/src/telemetry/index.js	0.00%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3875      +/-   ##
==========================================
- Coverage   84.73%   84.66%   -0.07%     
==========================================
  Files         237      237              
  Lines        9937     9967      +30     
  Branches       33       33              
==========================================
+ Hits         8420     8439      +19     
- Misses       1517     1528      +11     

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[pr-commenter]

Benchmarks

Benchmark execution time: 2023-12-20 18:39:14

Comparing candidate commit d6f8681 in PR branch rc-custom-tags with baseline commit db16b8d in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 519 metrics, 13 unstable metrics.

[ida613]

The config value names will be normalized when sent to the backend.
sampleRate and DD_TRACE_SAMPLE_RATE map to the same thing, logInjection is accepted but DD_LOG_INJECTION won't be recognized. We need to create a PR to config_norm_rules so that headerTags will be accepted. DD_TAGS will be accepted but tags won't be recognized. Since we will be sending the other config values to the backend with camel case names, I'm suggesting we do that here too, and create a PR to the json file to add the missing mappings.

[rochdev]

Not sure I understand. Are you saying that the value that is literally used by the backend to send the information to us will not be recognized by the same backend when reported as telemetry? If that's the case it sounds like a bug in the backend that should be fixed, and thus I don't think it's on us to change anything in another PR. The safe approach is to send the same names we received.

[rochdev]

I asked about this and was told this is all still in flight and not required to be correct for now. System tests will be added when we know exactly the values that need to be sent.