Move cloud metadata packages and kubernetes resources marshaling to internal

Decouples cloud provider metadata packages from kubernetes related code

Signed-off-by: Malte Poll <mp@edgeless.systems>

internal/cloud/gcp/autoscaler.go

@@ -0,0 +1,59 @@
+package gcp
+
+import (
+	"github.com/edgelesssys/constellation/internal/kubernetes"
+	k8s "k8s.io/api/core/v1"
+)
+
+// Autoscaler holds the GCP cluster-autoscaler configuration.
+type Autoscaler struct{}
+
+// Name returns the cloud-provider name as used by k8s cluster-autoscaler.
+func (a *Autoscaler) Name() string {
+	return "gce"
+}
+
+// Secrets returns a list of secrets to deploy together with the k8s cluster-autoscaler.
+func (a *Autoscaler) Secrets(instance, cloudServiceAccountURI string) (kubernetes.Secrets, error) {
+	return kubernetes.Secrets{}, nil
+}
+
+// Volumes returns a list of volumes to deploy together with the k8s cluster-autoscaler.
+func (a *Autoscaler) Volumes() []k8s.Volume {
+	return []k8s.Volume{
+		{
+			Name: "gcekey",
+			VolumeSource: k8s.VolumeSource{
+				Secret: &k8s.SecretVolumeSource{
+					SecretName: "gcekey",
+				},
+			},
+		},
+	}
+}
+
+// VolumeMounts returns a list of volume mounts to deploy together with the k8s cluster-autoscaler.
+func (a *Autoscaler) VolumeMounts() []k8s.VolumeMount {
+	return []k8s.VolumeMount{
+		{
+			Name:      "gcekey",
+			ReadOnly:  true,
+			MountPath: "/var/secrets/google",
+		},
+	}
+}
+
+// Env returns a list of k8s environment key-value pairs to deploy together with the k8s cluster-autoscaler.
+func (a *Autoscaler) Env() []k8s.EnvVar {
+	return []k8s.EnvVar{
+		{
+			Name:  "GOOGLE_APPLICATION_CREDENTIALS",
+			Value: "/var/secrets/google/key.json",
+		},
+	}
+}
+
+// Supported is used to determine if we support autoscaling for the cloud provider.
+func (a *Autoscaler) Supported() bool {
+	return true
+}