fix(ssi): remove newly added config variables

[betterengineering]

What does this PR do?

This change removes the webhook specific config values for enabled/disabled namespaces and cleans up some variable names missed during a refactor. Along with #33599, this should maintain the current released agent expectations that the config and tagsfromlabels webhook will execute in the following conditions:

• admission_controller.mutate_unlabelled is set to true
• SSI is enabled and the pod matches enabled/disabled namespaces

Motivation

We added these config variables in fix(ssi): decouple admission controller webhooks as part of Decoupling Admission Controller Webhooks. After more consideration, we decided that we don't actually want to support these and don't believe they are actually necessary unless a user was abusing apm_config.instrumentation.disabled_namespaces which feels unlikely.

Describe how you validated your changes

I ensured injection still worked as expected with the following helm config:

datadog:
  apiKeyExistingSecret: datadog-secret
  apm:
    instrumentation:
      enabled: true

I ensured the following config with APM disabled would still apply config and tagstolabels:

clusterAgent:
  enabled: true
  admissionController:
    mutateUnlabelled: true

Finally, I ensured that no mutations occurred with mutateUnlablled and apm.instrumentation.enabled set to false.

Possible Drawbacks / Trade-offs

See Decoupling Admission Controller Webhooks

Additional Notes

We have a meeting scheduled for February 18th to finalize this decision with the group once everyone is back from vacation, but it feels safer to have these options removed for now.

[betterengineering]

@davidor Just to confirm, there is no expected change as a result of this change series?

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 26f02af0-0b14-4287-99ef-3120669ae027

Baseline: 9751798
Comparison: 0f848a1
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	tcp_syslog_to_blackhole	ingress throughput	+1.73	[+1.66, +1.81]	1	Logs
➖	file_tree	memory utilization	+0.15	[+0.07, +0.22]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.28, +0.28]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.02, +0.01]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	-0.01	[-0.87, +0.84]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	-0.02	[-0.67, +0.62]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.03	[-0.81, +0.76]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-0.04	[-0.11, +0.02]	1	Logs bounds checks dashboard
➖	file_to_blackhole_0ms_latency_http2	egress throughput	-0.05	[-0.98, +0.89]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.05	[-0.77, +0.67]	1	Logs
➖	file_to_blackhole_0ms_latency_http1	egress throughput	-0.09	[-0.99, +0.82]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	-0.33	[-0.80, +0.13]	1	Logs
➖	quality_gate_idle	memory utilization	-0.44	[-0.48, -0.39]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.59	[-3.64, +2.46]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.75	[-1.55, +0.05]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-2.43	[-3.30, -1.56]	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	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10
✅	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, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check intake_connections: 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 intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.