Merge pull request 'feat: example install & upgrade script' (#4) from limiting-factor/k8s:wip-install into main

Reviewed-on: https://code.forgejo.org///infrastructure/k8s/pulls/4
Reviewed-by: earl-warren <earl-warren@noreply.code.forgejo.org>

README.md

@@ -114,6 +114,28 @@ sudo ln -s forgejo-v8 forgejo-v9
 sudo systemctl restart wakeup-on-logs-run
 ```
 
+```sh
+#!/bin/bash
+
+set -x
+
+self="${BASH_SOURCE[0]}"
+name=$(basename $self)
+# keep it lower than https://code.forgejo.org/infrastructure/wakeup-on-logs
+# otherwise it will get killed by it
+timeout=4m
+
+function lxc_run() {
+    lxc-attach $name -- sudo --user debian KUBECONFIG=/etc/rancher/k3s/k3s.yaml "$@" |& tee -a /var/log/$name.log
+}
+
+image=codeberg.org/forgejo-experimental/forgejo
+major=${name##*v}
+digest=$(skopeo inspect --format "{{.Digest}}" docker://$image:$major-rootless)
+values=https://code.forgejo.org/infrastructure/k8s/raw/branch/main/forgejo-v$major/values.yml
+lxc_run helm upgrade forgejo -f $values -f /home/debian/secrets.yml oci://code.forgejo.org/forgejo-helm/forgejo --atomic --wait --timeout $timeout --install --set image.digest=$digest
+```
+
 ## Define Forgejo Helm values
 
 * https://code.forgejo.org/infrastructure/k8s/src/branch/main/forgejo-v$version/values.yml