Allow setting raw url for app tarballs

templates/nextcloud-onlyoffice-config.yaml

@@ -99,10 +99,16 @@ data:
       # Where to install the app
       target_directory="/var/www/html/custom_apps"
       # We need to edit $ to be able to use `tpl` inside a `range`,
-      # see https://github.com/helm/helm/issues/5979#issuecomment-518231758
-      # allows us to use version variable in the release_filename
+      # see https://github.com/helm/helm/issues/5979#issuecomment-518231758 .
+      # This allows us to use version variable in the `release_filename` or
+      # `raw_url`.
       {{- $_ := set $ "version" .version}}
-      curl "https://github.com/{{ .github_repository }}/releases/download/{{ .version }}/{{ tpl .release_filename $ }}" -Lo "{{ .name }}.tar.gz"
+      {{- if .raw_url }}
+      url="{{ tpl .raw_url }}"
+      {{- else }}
+      url="https://github.com/{{ .github_repository }}/releases/download/{{ .version }}/{{ tpl .release_filename $ }}"
+      {{- end }} # end if .raw_url
+      curl "$url" -Lo "{{ .name }}.tar.gz"
       # If the above url results in a 404, curl will not complain and store the
       # body of the 404 in the file :/. So we check here whether we actually
       # got a valid archive; `tar` will fail if not.