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/kubernetes/secrets_test.go

@@ -0,0 +1,49 @@
+package kubernetes
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	k8s "k8s.io/api/core/v1"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestSecrets(t *testing.T) {
+	require := require.New(t)
+	assert := assert.New(t)
+
+	secrets := Secrets{
+		&k8s.Secret{
+			TypeMeta: v1.TypeMeta{
+				Kind:       "Secret",
+				APIVersion: "v1",
+			},
+			Data: map[string][]byte{"key": []byte("value1")},
+		},
+		&k8s.Secret{
+			TypeMeta: v1.TypeMeta{
+				Kind:       "Secret",
+				APIVersion: "v1",
+			},
+			Data: map[string][]byte{"key": []byte("value2")},
+		},
+	}
+	data, err := secrets.Marshal()
+	require.NoError(err)
+
+	assert.Equal(`apiVersion: v1
+data:
+  key: dmFsdWUx
+kind: Secret
+metadata:
+  creationTimestamp: null
+---
+apiVersion: v1
+data:
+  key: dmFsdWUy
+kind: Secret
+metadata:
+  creationTimestamp: null
+`, string(data))
+}