storage: Use Authelia for Longhorn UI auth

Instead of using a static username/password and HTTP Basic
authentication for the Longhorn UI, we can now use Authelia via the
*nginx* auth subrequest functionality.

storage/README.md

@@ -23,18 +23,11 @@ kubectl apply -f longhorn.yaml
 Expose the Longhorn UI outside the cluster:
 
 ```sh
-printf 'Longhorn username: '
-read longhorn_username
-printf 'Longhorn password: '
-read -s longhorn_password
-printf '%s:%s\n' \
-    "${longhorn_username}" \
-    "$(openssl passwd -stdin -apr1 <<< "${longhorn_password}")" \
-    > auth
-kubectl create secret generic -n longhorn-system basic-auth --from-file auth
 kubectl apply -f longhorn-ingress.yaml
 ```
 
+Authentication to the UI is handled by Authelia.
+
 
 [0]: https://longhorn.io/docs/1.3.0/deploy/install/install-with-kubectl/
 [1]: https://longhorn.io/docs/1.3.0/advanced-resources/deploy/node-selector/

storage/longhorn-ingress.yaml

@@ -4,14 +4,12 @@ metadata:
   name: longhorn-ingress
   namespace: longhorn-system
   annotations:
-    # type of authentication
-    nginx.ingress.kubernetes.io/auth-type: basic
-    # prevent the controller from redirecting (308) to HTTPS
-    nginx.ingress.kubernetes.io/ssl-redirect: 'false'
-    # name of the secret that contains the user/password definitions
-    nginx.ingress.kubernetes.io/auth-secret: basic-auth
-    # message to display with an appropriate context why the authentication is required
-    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required '
+    nginx.ingress.kubernetes.io/auth-method: GET
+    nginx.ingress.kubernetes.io/auth-url: http://authelia.authelia.svc.cluster.local:9091/api/verify
+    nginx.ingress.kubernetes.io/auth-signin: https://auth.pyrocufflink.blue/?rm=$request_method
+    nginx.ingress.kubernetes.io/auth-response-headers: Remote-User,Remote-Name,Remote-Groups,Remote-Email
+    nginx.ingress.kubernetes.io/auth-snippet: |
+      proxy_set_header X-Forwarded-Method $request_method;
     # custom max body size for file uploading like backing image uploading
     nginx.ingress.kubernetes.io/proxy-body-size: 10000m
 spec: