feat: add cert-manager

cluster/core/namespaces/cert-manger.yaml

@@ -0,0 +1,5 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: cert-manager

cluster/core/namespaces/kustomization.yaml

@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- cert-manager.yaml
+- networking.yaml

cluster/core/namespaces/networking.yaml

@@ -0,0 +1,5 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: networking