[AGENTONB-2593] DDOT gateway with interface component

[tbavelier]

What does this PR do?

Start implementing DDOT gateway interfaces using the componentreconciler

Note the actual gateway feature, RBAC, HPA etc. are not yet implemented in this PR and will be in follow-up PRs.

Motivation

Working towards DDOT gateway support in operator

Additional Notes

No QA needed for now since this PR only adds the interfaces but no implementations.

Minimum Agent Versions

Are there minimum versions of the Datadog Agent and/or Cluster Agent required?

• Agent: vX.Y.Z
• Cluster Agent: vX.Y.Z

Describe your test plan

Write there any instructions and details you may have to test your PR.

Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label

[codecov-commenter]

Codecov Report

❌ Patch coverage is 10.64815% with 193 lines in your changes missing coverage. Please review.
✅ Project coverage is 37.09%. Comparing base (490d736) to head (185911c).

Files with missing lines	Patch %	Lines
...dogagentinternal/component_otelcollectorgateway.go	0.00%	48 Missing ⚠️
...datadogagent/component/otelagentgateway/default.go	0.00%	45 Missing ⚠️
...ler/datadogagent/component_otelcollectorgateway.go	43.75%	26 Missing and 1 partial ⚠️
...r/datadogagent/feature/otelagentgateway/feature.go	0.00%	25 Missing ⚠️
...nal/controller/datadogagent/global/dependencies.go	0.00%	13 Missing ⚠️
...roller/datadogagent/global/otelcollectorgateway.go	0.00%	8 Missing ⚠️
pkg/testutils/builder.go	0.00%	8 Missing ⚠️
pkg/constants/utils.go	0.00%	7 Missing ⚠️
internal/controller/datadogagent/common/utils.go	0.00%	4 Missing ⚠️
.../controller/datadogagent/feature/test/testsuite.go	0.00%	4 Missing ⚠️
... and 2 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2276      +/-   ##
==========================================
- Coverage   37.32%   37.09%   -0.23%     
==========================================
  Files         290      296       +6     
  Lines       24720    24935     +215     
==========================================
+ Hits         9226     9249      +23     
- Misses      14781    14971     +190     
- Partials      713      715       +2     

Flag	Coverage Δ
unittests	37.09% <10.64%> (-0.23%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
internal/controller/datadogagent/controller.go	53.57% <100.00%> (+1.71%)	⬆️
internal/controller/datadogagent/profile.go	73.61% <100.00%> (+0.18%)	⬆️
...er/datadogagent/component/otelagentgateway/rbac.go	0.00% <0.00%> (ø)
...er/datadogagent/controller_reconcile_v2_helpers.go	54.96% <0.00%> (-0.86%)	⬇️
internal/controller/datadogagent/common/utils.go	0.00% <0.00%> (ø)
.../controller/datadogagent/feature/test/testsuite.go	0.00% <0.00%> (ø)
pkg/constants/utils.go	8.20% <0.00%> (-0.46%)	⬇️
...roller/datadogagent/global/otelcollectorgateway.go	0.00% <0.00%> (ø)
pkg/testutils/builder.go	0.00% <0.00%> (ø)
...nal/controller/datadogagent/global/dependencies.go	18.87% <0.00%> (-1.04%)	⬇️
... and 4 more

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 490d736...185911c. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[songy23]

A high-level question: where are Services defined in operator? In DDOT Gateway we need to create a k8s Service to expose the gateway pods: https://github.com/DataDog/helm-charts/blob/main/charts/datadog/templates/agent-services.yaml#L119

[tbavelier]

A high-level question: where are Services defined in operator? In DDOT Gateway we need to create a k8s Service to expose the gateway pods: https://github.com/DataDog/helm-charts/blob/main/charts/datadog/templates/agent-services.yaml#L119

This is done within the ManageDependencies of a feature. Added in 0363326:

╰─❯ k describe svc datadog-agent-otel-collector-gateway
Name:                     datadog-agent-otel-collector-gateway
Namespace:                system
Labels:                   app.kubernetes.io/instance=datadog-agent
                          app.kubernetes.io/managed-by=datadog-operator
                          app.kubernetes.io/name=datadog-agent-deployment
                          app.kubernetes.io/part-of=system-datadog--agent
                          app.kubernetes.io/version=
                          operator.datadoghq.com/managed-by-store=true
Annotations:              <none>
Selector:                 agent.datadoghq.com/component=otel-collector-gateway,app.kubernetes.io/part-of=system-datadog--agent
Type:                     ClusterIP
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       10.96.102.42
IPs:                      10.96.102.42
Port:                     otlpgrpcport  4317/TCP
TargetPort:               4317/TCP
Endpoints:                10.244.1.10:4317
Port:                     otlphttpport  4318/TCP
TargetPort:               4318/TCP
Endpoints:                10.244.1.10:4318
Session Affinity:         None
Internal Traffic Policy:  Local
Events:                   <none>

[songy23]

Looks good so far, just a few naming suggestions