[CONTP-517] Support None card in tagger

[gabedos]

What does this PR do?

Adds support for the none cardinality in the tagger. This excludes global tags but keeps host tags.

Motivation

Some teams want no tags on metrics because even low cardinality is too high. Provides customers with more flexible/control on the amount of unique metrics generated.

Describe how you validated your changes

Deploy the following values.yaml

datadog:
  kubelet:
    tlsVerify: false
  checksCardinality: none
agents:
  image:
    tag: <INSERT_TAG>
    pullPolicy: IfNotPresent

As various checks run, they will query the tagger with the none cardinality and increase the telemetry count.

k exec -it -n datadog-agent datadog-agent-linux-xbg46 -- curl -sq http://localhost:6000/telemetry | grep "=\"none\"" > tel.txt

================================================================
logs_client_http_destination__send{endpoint_host="contimage-intake.datadoghq.com",error="none"} 85
tagger_queries{cardinality="none",status="empty_entity_id"} 0
tagger_queries{cardinality="none",status="empty_tags"} 0
tagger_queries{cardinality="none",status="success"} 1403

We can also verify that extra tags aren't being added by running the checks locally and looking at the tags. We should only expect to see a few of the tags that the coredns check manually adds on top of the default tags. Typically we expect to see tags like image_name, kube_container_name, etc.

k exec -it datadog-agent-linux-jd9p7 -n datadog-agent -- agent check coredns > none-coredns.txt

...
"tags": [
      "dns-pod:10.244.0.2",
      "proto:udp",
      "server:dns://:53",
      "upper_bound:none",
      "view:",
      "zone:."
    ]
...

Possible Drawbacks / Trade-offs

N/A

Additional Notes

[agent-platform-auto-pr]

Package size comparison

Comparison with ancestor a7ba9110c9023ca31f2c5e913a7ff98ab31a9a5b

Diff per package

package	diff	status	size	ancestor	threshold
datadog-agent-amd64-deb	-1.40MB	✅	1270.67MB	1272.08MB	140.00MB
datadog-iot-agent-amd64-deb	0.00MB	⚠️	113.20MB	113.20MB	10.00MB
datadog-dogstatsd-amd64-deb	0.00MB	✅	78.32MB	78.32MB	10.00MB
datadog-heroku-agent-amd64-deb	-1.40MB	✅	526.45MB	527.85MB	70.00MB
datadog-agent-x86_64-rpm	-1.40MB	✅	1279.91MB	1281.31MB	140.00MB
datadog-agent-x86_64-suse	-1.40MB	✅	1279.91MB	1281.31MB	140.00MB
datadog-iot-agent-x86_64-rpm	0.00MB	⚠️	113.27MB	113.26MB	10.00MB
datadog-iot-agent-x86_64-suse	0.00MB	⚠️	113.26MB	113.26MB	10.00MB
datadog-dogstatsd-x86_64-rpm	-0.00MB	✅	78.40MB	78.40MB	10.00MB
datadog-dogstatsd-x86_64-suse	-0.00MB	✅	78.40MB	78.40MB	10.00MB
datadog-agent-arm64-deb	0.00MB	✅	1004.85MB	1004.85MB	140.00MB
datadog-iot-agent-arm64-deb	-0.00MB	✅	108.67MB	108.67MB	10.00MB
datadog-dogstatsd-arm64-deb	0.00MB	⚠️	55.59MB	55.59MB	10.00MB
datadog-agent-aarch64-rpm	0.00MB	⚠️	1014.06MB	1014.06MB	140.00MB
datadog-iot-agent-aarch64-rpm	-0.00MB	✅	108.74MB	108.74MB	10.00MB

Decision

⚠️ Warning

[agent-platform-auto-pr]

Test changes on VM

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

inv aws.create-vm --pipeline-id=50698923 --os-family=ubuntu

Note: This applies to commit 354c367

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: bf22467f-6ba1-42b6-bb3d-f986ed7265a4

Baseline: a7ba911
Comparison: 354c367
Diff

Optimization Goals: ❌ Regression(s) detected

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
❌	quality_gate_logs	% cpu utilization	+6.25	[+3.25, +9.25]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
❌	quality_gate_logs	% cpu utilization	+6.25	[+3.25, +9.25]	1	Logs
➖	quality_gate_idle	memory utilization	+0.43	[+0.39, +0.48]	1	Logs bounds checks dashboard
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+0.23	[-0.50, +0.97]	1	Logs
➖	otel_to_otel_logs	ingress throughput	+0.20	[-0.48, +0.88]	1	Logs
➖	file_tree	memory utilization	+0.03	[-0.10, +0.15]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.00	[-0.01, +0.01]	1	Logs
➖	file_to_blackhole_0ms_latency_http1	egress throughput	-0.01	[-0.85, +0.82]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.02	[-0.11, +0.06]	1	Logs
➖	file_to_blackhole_0ms_latency_http2	egress throughput	-0.03	[-0.90, +0.83]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.05	[-0.81, +0.72]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	-0.06	[-0.69, +0.58]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	-0.07	[-0.53, +0.38]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-0.12	[-0.23, -0.00]	1	Logs bounds checks dashboard
➖	file_to_blackhole_100ms_latency	egress throughput	-0.13	[-0.85, +0.58]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	-0.15	[-1.04, +0.74]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.41	[-1.19, +0.37]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-1.83	[-1.92, -1.75]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_0ms_latency_http1	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency_http1	memory_usage	10/10
✅	file_to_blackhole_0ms_latency_http2	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency_http2	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency_linear_load	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	lost_bytes	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_300ms_latency	lost_bytes	10/10
✅	file_to_blackhole_300ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	lost_bytes	10/10
✅	quality_gate_logs	memory_usage	10/10

Explanation

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

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

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".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.