Add k8s deployment, standalone app Dockerfile.

Tested with Rancher k3s. See k8s/README.md for site configuration and
deployment instructions.

Add cert-manager, tls, remote headscale script.

k8s/base/kustomization.yaml

@@ -0,0 +1,42 @@
+namespace: headscale
+resources:
+- configmap.yaml
+- ingress.yaml
+- service.yaml
+generatorOptions:
+  disableNameSuffixHash: true
+configMapGenerator:
+- name: headscale-site
+  files:
+  - derp.yaml=site/derp.yaml
+  envs:
+  - site/public.env
+- name: headscale-etc
+  literals:
+  - config.json={}
+secretGenerator:
+- name: headscale
+  files:
+  - secrets/private-key
+vars:
+- name: PUBLIC_PROTO
+  objRef:
+    kind: ConfigMap
+    name: headscale-site
+    apiVersion: v1
+  fieldRef:
+    fieldPath: data.public-proto
+- name: PUBLIC_HOSTNAME
+  objRef:
+    kind: ConfigMap
+    name: headscale-site
+    apiVersion: v1
+  fieldRef:
+    fieldPath: data.public-hostname
+- name: CONTACT_EMAIL
+  objRef:
+    kind: ConfigMap
+    name: headscale-site
+    apiVersion: v1
+  fieldRef:
+    fieldPath: data.contact-email