Add Velero and snapshot controller for backups

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

_includes/kubernetes-flux-kustomization.md

@@ -0,0 +1,26 @@
+### Kustomization
+
+Now that the "global" elements of this deployment (*just the HelmRepository in this case*) have been defined, we do some "flux-ception", and go one layer deeper, adding another Kustomization, telling flux to deploy any YAMLs found in the repo at `/{{ page.meta.helmrelease_namespace }}/`. I create this example Kustomization in my flux repo:
+
+```yaml title="/bootstrap/kustomizations/kustomization-{{ page.meta.kustomization_name }}.yaml"
+apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
+kind: Kustomization
+metadata:
+  name: {{ page.meta.kustomization_name }}
+  namespace: flux-system
+spec:
+  interval: 30m
+  path: ./{{ page.meta.helmrelease_namespace }}
+  prune: true # remove any elements later removed from the above path
+  timeout: 10m # if not set, this defaults to interval duration, which is 1h
+  sourceRef:
+    kind: GitRepository
+    name: flux-system
+  healthChecks:
+    - apiVersion: helm.toolkit.fluxcd.io/v2beta1
+      kind: HelmRelease
+      name: {{ page.meta.helmrelease_name }}
+      namespace: {{ page.meta.helmrelease_namespace }}
+```
+
+--8<-- "premix-cta-kubernetes.md"