[DatadogAgent][Flare] Additional environment variables and RBAC to permit user manifests retrieval

[tbavelier]

What does this PR do?

• Adds 3 env vars to the cluster Agent:
  • AGENT_DAEMONSET: name of the node Agent ds
  • CLUSTER_AGENT_DEPLOYMENT: name of the DCA deployment
  • DATADOG_AGENT_CR_NAME: name of the DatadogAgent custom resource
• Adds RBAC allowing the DCA to get the DatadogAgent custom resource from its namespace

Motivation

Similar to DataDog/helm-charts#965, we need to inject a few variables/give some permissions to be able to collect the Agent deployment files while creating a flare to help with troubleshooting.

Additional Notes

The flare feature depending on these variables is available at: DataDog/datadog-agent#30372

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

• Deploy the operator
• Deploy a DatadogAgent with cluster Agent enabled (default):

apiVersion: datadoghq.com/v2alpha1
kind: DatadogAgent
metadata:
  name: foo

• Assert on DCA:
  • AGENT_DAEMONSET: foo-agent, value of kubectl get ds
  • CLUSTER_AGENT_DEPLOYMENT: foo-cluster-agent, value of kubectl get deploy
  • DATADOG_AGENT_CR_NAME: foo, value of kubectl get dd
• Add overrides:

apiVersion: datadoghq.com/v2alpha1
kind: DatadogAgent
metadata:
  name: foo
override:
  nodeAgent:
    name: "x"
  clusterAgent:
    name: "y"

• Assert on DCA:
  • AGENT_DAEMONSET: x, value of kubectl get ds
  • CLUSTER_AGENT_DEPLOYMENT: y, value of kubectl get deploy
  • DATADOG_AGENT_CR_NAME: foo, value of kubectl get dd

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

Attention: Patch coverage is 76.47059% with 8 lines in your changes missing coverage. Please review.

Project coverage is 48.75%. Comparing base (7b66b25) to head (d3e2ead).

Files with missing lines	Patch %	Lines
...troller/datadogagent/feature/enabledefault/rbac.go	0.00%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1477      +/-   ##
==========================================
+ Coverage   48.70%   48.75%   +0.04%     
==========================================
  Files         224      225       +1     
  Lines       19845    19879      +34     
==========================================
+ Hits         9666     9692      +26     
- Misses       9670     9678       +8     
  Partials      509      509              

Flag	Coverage Δ
unittests	48.75% <76.47%> (+0.04%)	⬆️

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

Files with missing lines	Coverage Δ
...ller/datadogagent/feature/enabledefault/feature.go	37.36% <100.00%> (+2.79%)	⬆️
...roller/datadogagent/feature/enabledefault/utils.go	100.00% <100.00%> (ø)
...troller/datadogagent/feature/enabledefault/rbac.go	0.00% <0.00%> (ø)

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[celenechang]

Suggested change

	DDAgentDaemonSet = "AGENT_DAEMONSET"
	DDClusterAgentDeployment = "CLUSTER_AGENT_DEPLOYMENT"
	DDDatadogAgentCustomResource = "DATADOG_AGENT_CR_NAME"
	DDAgentDaemonSet = "NODE_AGENT_DAEMONSET"
	DDClusterAgentDeployment = "CLUSTER_AGENT_DEPLOYMENT"
	DDDatadogAgentCustomResource = "DATADOGAGENT_CR_NAME"