Add guide for deploying EDOT Collector using OpenTelemetryCollector custom resources

[alexandra5000]

Summary

Closes #6062.

Adds a new page explaining how to deploy the EDOT Collector on Kubernetes using OpenTelemetryCollector custom resources (CRs) directly, covering the gateway (Deployment) and DaemonSet (agent) modes.

Background and scope

The original issue requested documentation for deploying the EDOT Collector via the OpenTelemetry Kubernetes Operator using Agent and Gateway modes. During scoping (with @hegerchr), we found that:

• The existing solutions docs already cover the recommended deployment path (the opentelemetry-kube-stack Helm chart) in the Kubernetes use-case section.
• The gap Chris had identified was in the reference docs, as there were no CR-based examples for the Collector comparable to the SDK setup pages (for example, Java SDK on K8s).

What it is: an alternative deployment path for users who need direct CR control (GitOps, no-Helm environments, fine-grained customisation).
What it is not: a replacement for the Helm chart guide or a guide for auto-instrumentation (covered by existing pages).

Open questions for technical review

• resourcedetection/eks|gcp|aks processors: the DaemonSet example includes only resourcedetection/system and notes that cloud-specific detectors should be added. Confirm this is an acceptable simplification or whether the guide should show all three variants.
• cgroupruntime extension: present in the kube-stack cluster collector config but omitted here for brevity. Confirm whether it is required for correct operation or is optional.
• elastic-otel-collector vs elastic-agent image for the Helm chart: the kube-stack chart currently deploys elastic-agent/elastic-agent (with ELASTIC_AGENT_OTEL=true), not elastic-otel-collector. This guide uses elastic-otel-collector as appropriate for a CR-based manual deployment. Confirm this is the correct recommendation for standalone CR use.

Generative AI disclosure

Did you use a generative AI (GenAI) tool to assist in creating this contribution?

• Yes

Tool(s) and model(s) used: Claude Sonnet 4.6 (Claude Code)

[github-actions]

Elastic Docs AI PR menu

Check the box to run an AI review for this pull request.

• Review docs changes (docs-review). Status: not started.

Powered by GitHub Agentic Workflows and docs-actions. For more information, reach out to the docs team.

[github-actions]

🔍 Preview links for changed docs

• solutions/observability/get-started/opentelemetry/use-cases/kubernetes/collector-custom-resource.md

[github-actions]

Elastic Docs Style Checker (Vale)

Summary: 1 warning found

⚠️ Warnings (1): Fix when the suggestion improves clarity or correctness.

File	Line	Rule	Message
solutions/observability/get-started/opentelemetry/use-cases/kubernetes/collector-custom-resource.md	475	Elastic.DirectionalLanguage	Don't use directional language. Use 'the preceding element' instead of 'The example above'.

---

The Vale linter checks documentation changes against the Elastic Docs style guide. To use Vale locally or report issues, refer to Elastic style guide for Vale.