Fix duplicate tags in TCP/UDP logs

[andrewqian2001datadog]

What does this PR do?

Fixes bug where duplicate tags occur in UDP/TCP logs

Motivation

Issue

Describe how to test/QA your changes

Inside conf.yaml, add the following
Create the file if needed dev/dist/conf.d/test.d/conf.yaml

logs:
  - type: udp
    port: 10518
    service: "test_app"
    source: "test_app_src"
    tags:
      - "name:integrationtag"

Inside Datadog.yaml, enable logs and have tags as well

logs_enabled: true
tags:
  - "name:hosttag"

Run the agent
./bin/agent/agent run -c bin/agent/dist/datadog.yaml
In a different terminal, get the logs from the agent
./bin/agent/agent stream-logs -c bin/agent/dist/datadog.yaml
In a different terminal, send logs to the agent
echo -n "this is my log" | nc -u -w 1 127.0.0.1 10518
Ensure that the tags are not duplicated in the terminal that gets the logs

Different QA steps are also provided in the ticket if needed

[pr-commenter]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=45874840 --os-family=ubuntu

Note: This applies to commit 1bb1a6a

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Run ID: 211f477f-8fdf-475d-9ed3-83d4bba15ede Metrics dashboard Target profiles

Baseline: 8d63f09
Comparison: 1bb1a6a

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

No significant changes in experiment optimization goals

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	basic_py_check	% cpu utilization	+2.58	[-0.17, +5.34]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+1.34	[+0.60, +2.07]	1	Logs
➖	otel_to_otel_logs	ingress throughput	+0.81	[-0.00, +1.62]	1	Logs
➖	pycheck_lots_of_tags	% cpu utilization	+0.60	[-1.91, +3.11]	1	Logs
➖	idle_all_features	memory utilization	+0.46	[+0.37, +0.55]	1	Logs
➖	file_tree	memory utilization	+0.31	[+0.20, +0.41]	1	Logs
➖	idle	memory utilization	+0.06	[+0.02, +0.11]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	+0.03	[-0.03, +0.09]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.01	[-0.07, +0.06]	1	Logs

Bounds Checks

perf	experiment	bounds_check_name	replicates_passed
✅	idle	memory_usage	10/10

Explanation

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

[gh123man]

Code change and tests LGTM 👍
Lets update the title to something like: Fix duplicate tags in TCP/UDP logs (just so it's more clear when looking at the commit history).

And also it would be good to describe the problem and solution in the PR description. Links to JIRA are helpful, but when digging though git history it's convenient to have the additional context 😄

[gh123man]

Would it make sense to instead update the above CheckLogsExpected to check for duplicate tags?
That way we get dupe tag coverage for all test cases instead of just one. I don't think there is a good reason why we couldn't perform this check on all test cases.

[andrewqian2001datadog]

/merge

[dd-devflow]

🚂 MergeQueue: pull request added to the queue

The median merge time in main is 23m.

Use /merge -c to cancel this operation!