add rclone-openrc (#21)

Reviewed-on: #21

packaging/alpine/local/rclone-openrc/README.md

@@ -0,0 +1,59 @@
+# rclone OpenRC Alpine Package
+
+Provides a generic, instance-capable OpenRC service for Alpine's `rclone`
+package. It does not repackage the rclone binary.
+
+## Install
+
+```sh
+apk add rclone-openrc
+```
+
+The package creates the unprivileged `rclone` account, `/etc/rclone` for
+configuration and credentials, and `/var/lib/rclone/cache` for rclone state.
+It deliberately does not create remotes, credentials, authorized-key files, or
+SSH host keys; provision those as machine-specific secrets.
+
+## Create an Instance
+
+Copy the template and symlink the generic service under an instance name:
+
+```sh
+cp /etc/conf.d/rclone /etc/conf.d/rclone.sftp
+ln -s rclone /etc/init.d/rclone.sftp
+```
+
+For an SFTP server, configure `/etc/conf.d/rclone.sftp`:
+
+```sh
+RCLONE_COMMAND="serve sftp"
+RCLONE_REMOTE="/srv/storage"
+RCLONE_ARGS="
+  --addr :2022
+  --authorized-keys /etc/rclone/authorized_keys
+  --key /etc/rclone/ssh_host_ed25519_key
+  --log-level INFO
+"
+```
+
+Then enable and start it:
+
+```sh
+rc-update add rclone.sftp default
+rc-service rclone.sftp start
+```
+
+Other instances, such as `rclone.webdav` or `rclone.rcd`, use their own
+`/etc/conf.d/rclone.<name>` file with the same generic init script. The service
+runs rclone in the foreground under `supervise-daemon`, which restarts it after
+an unexpected exit. Set `RCLONE_RESPAWN_MAX` to a positive value to limit
+restart attempts.
+
+## Package Commands
+
+```sh
+ALPINE_PACKAGE=rclone-openrc mise run apk:checksum
+ALPINE_PACKAGE=rclone-openrc mise run apk:build
+ALPINE_PACKAGE=rclone-openrc SKIP_BUILD=1 mise run apk:test-install
+ALPINE_PACKAGE=rclone-openrc mise run apk:runtime-test
+```