docs: auto-updater

docs/operators/tutorial.md

@@ -252,6 +252,46 @@ abra app errors -w <nextcloud-domain> # error catcher
 
 Your new `traefik` instance will detect that a new app is coming up and generate SSL certificates for it. You can see what `traefik` is up to using the same commands above but replacing `<netcloud-domain>` with the `<traefik-domain>` you chose earlier (`abra app ls` will remind you what domains you chose :grinning:).
 
+### Upgrade Nextcloud
+
+To upgrade an app manually to the newest available version run:
+
+```bash
+abra app upgrade <nextcloud-domain>
+```
+
+### Automatic Upgrades
+
+`kadabra` the auto-updater is still under development, use it with care and don't use it in production environments.
+To setup the auto-updater copy the `kadabra` binary to the server and configure a cronjob for regular app upgrades.
+The following script will configure ssmtp for email notifications and setup a cronjob.
+This cronjob checks daily for new app versions, notifies if any kind of update is available and upgrades all apps to the latest patch/minor version.
+
+
+```bash
+apt install ssmtp
+
+cat > /etc/ssmtp/ssmtp.conf << EOF
+mailhub=$MAIL_SERVER:587
+hostname=$MAIL_DOMAIN
+AuthUser=$USER
+AuthPass=$PASSWORD
+FromLineOverride=yes
+UseSTARTTLS=yes
+EOF
+
+cat > /etc/cron.d/abra_updater << EOF
+MAILTO=admin@example.com
+MAILFROM=noreply@example.com
+
+0  6 * * *       root    ~/kadabra notify --major
+30 4 * * *       root    ~/kadabra upgrade --all
+EOF
+
+
+```
+
+
 ## Finishing up
 
 Hopefully you got something running! Well done! The [operators handbook](/operators/handbook) would probably be the next place to go check out if you're looking for more help. Especially on topics of ongoing maintenance.