cluster-agent network policy breaks cluster-name autodiscovery on GKE

[hanikesn]

Describe what happened:

CLUSTER | DEBUG | (pkg/util/kubernetes/clustername/clustername.go:97 in getClusterName) | Unable to auto discover the cluster name from the gce API: unable to retrieve clustername from GCE: GCE metadata API error: Get "http://169.254.169.254/computeMetadata/v1/instance/attributes/cluster-name": context deadline exceeded (Client.Timeout exceeded while awaiting headers)

The egress to port 80 is blocked here:

helm-charts/charts/datadog/templates/cluster-agent-network-policy.yaml

Lines 56 to 64 in 85d3e69

	- # Egress to
	# * Datadog intake
	# * Kube API server
	# * DNS
	ports:
	- port: 443
	- port: 6443
	- port: 53
	protocol: UDP

Describe what you expected:

CLUSTER | DEBUG | (pkg/util/kubernetes/clustername/clustername.go:94 in getClusterName) | Trying to auto discover the cluster name from the gce API...
CLUSTER | DEBUG | (pkg/config/setup/config.go:2010 in IsCloudProviderEnabled) | cloud_provider_metadata is set to [gcp] in agent configuration, trying endpoints for GCP Cloud Provider
CLUSTER | DEBUG | (pkg/util/http/transport.go:135 in 1) | URL 'http://169.254.169.254/computeMetadata/v1/instance/attributes/cluster-name' matches no_proxy list item '169.254.169.254': not using any proxy
CLUSTER | INFO | (pkg/util/kubernetes/clustername/clustername.go:104 in getClusterName) | Using cluster name XXX auto discovered from the gce API

Steps to reproduce the issue:

  datadog:
    networkPolicy:
      create: true

Additional environment details (Operating System, Cloud provider, etc):
Chart version: 3.59.6
Agent version 7.52.1