rTorrent: Allow linux screen launch

This pull requests add the `RT_DAEMON_MODE` environment variable which allows the user to configure how rTorrent is launched.

rTorrent is still launched in daemon mode by default unless the user changes it. When daemon mode is disabled, rTorrent will launch in the foreground on a linux screen instead.

This has some graceful exit benefits in limited circumstances. See crazy-max#311

Dockerfile

@@ -241,6 +241,7 @@ RUN apk --update --no-cache add \
     php82-zip \
     python3 \
     py3-pip \
+    screen \
     shadow \
     sox \
     tar \

README.md

@@ -44,6 +44,7 @@ ___
   * [WAN IP address](#wan-ip-address)
   * [Configure rTorrent session saving](#configure-rtorrent-session-saving)
   * [Configure rTorrent tracker scrape](#rtorrent-tracker-scrape-patch)
+  * [Configure rTorrent launch mode](#rtorrent-launch-mode)
 * [Upgrade](#upgrade)
 * [Contributing](#contributing)
 * [License](#license)
@@ -139,6 +140,7 @@ Image: crazymax/rtorrent-rutorrent:latest
 * `RT_TRACKER_DELAY_SCRAPE`: Delay tracker announces at startup (default `true`)
 * `RT_DHT_PORT`: DHT UDP port (`dht.port.set`, default `6881`)
 * `RT_INC_PORT`: Incoming connections (`network.port_range.set`, default `50000`)
+* `RT_DAEMON_MODE`: Run rTorrent in daemon mode (default `true`)
 
 ### ruTorrent
 
@@ -355,6 +357,13 @@ The default value is `true`. There are two main benefits to keeping this feature
 1) Software Stability: rTorrent will not crash or time-out with tens of thousands of trackers.
 2) Immediate Access: ruTorrent can be accessed immediately after rTorrent is started.
 
+## rTorrent launch mode
+`RT_DAEMON_MODE` when set to `true` will run rTorrent in the background using daemon mode.
+The default value is true for daemon mode. This will disable the rTorrent ncurses interface.
+
+`RT_DAEMON_MODE` when set to `false` will run rTorrent in the foreground using a linux screen.
+The name of the linux screen is `rtorrent`. This feature may be required for graceful exit.
+
 ## Upgrade
 
 To upgrade, pull the newer image and launch the container:

rootfs/etc/cont-init.d/03-config.sh

@@ -26,6 +26,7 @@ RT_LOG_EXECUTE=${RT_LOG_EXECUTE:-false}
 RT_LOG_XMLRPC=${RT_LOG_XMLRPC:-false}
 RT_SESSION_SAVE_SECONDS=${RT_SESSION_SAVE_SECONDS:-3600}
 RT_TRACKER_DELAY_SCRAPE=${RT_TRACKER_DELAY_SCRAPE:-true}
+RT_DAEMON_MODE=${RT_DAEMON_MODE:-true}
 
 RU_REMOVE_CORE_PLUGINS=${RU_REMOVE_CORE_PLUGINS:-httprpc}
 RU_HTTP_USER_AGENT=${RU_HTTP_USER_AGENT:-Mozilla/5.0 (Windows NT 6.0; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0}

rootfs/etc/cont-init.d/04-create-services.sh

@@ -25,12 +25,14 @@ cat > /etc/services.d/rtorrent/run <<EOL
 with-contenv
 /bin/export HOME /data/rtorrent
 /bin/export PWD /data/rtorrent
-s6-setuidgid ${PUID}:${PGID}
 EOL
-if [ -z "${WAN_IP}" ]; then
-  echo "rtorrent -D -o import=/etc/rtorrent/.rtlocal.rc" >> /etc/services.d/rtorrent/run
+
+[[ -z "${WAN_IP}" ]] && wan="" || wan="-i ${WAN_IP}"
+if [ "$RT_DAEMON_MODE" = false ]; then
+  echo "screen -D -m -S rtorrent s6-setuidgid ${PUID}:${PGID} rtorrent -D -o import=/etc/rtorrent/.rtlocal.rc ${wan}" >> /etc/services.d/rtorrent/run
 else
-  echo "rtorrent -D -o import=/etc/rtorrent/.rtlocal.rc -i ${WAN_IP}" >> /etc/services.d/rtorrent/run
+  echo "s6-setuidgid ${PUID}:${PGID}" >> /etc/services.d/rtorrent/run
+  echo "rtorrent -D -o import=/etc/rtorrent/.rtlocal.rc ${wan}" >> /etc/services.d/rtorrent/run
 fi
 
 chmod +x /etc/services.d/rtorrent/run

rootfs/tpls/etc/rtorrent/.rtlocal.rc

@@ -1,5 +1,5 @@
 # Launch as a daemon
-system.daemon.set = true
+system.daemon.set = @RT_DAEMON_MODE@
 
 # Instance layout
 method.insert = cfg.basedir, private|const|string, (cat,"/data/rtorrent/")

test/rtorrent-rutorrent.env

@@ -21,6 +21,7 @@ WEBDAV_AUTHBASIC_STRING=WebDAV restricted access
 RT_LOG_LEVEL=info
 RT_LOG_EXECUTE=false
 RT_LOG_XMLRPC=false
+RT_DAEMON_MODE=true
 
 RU_REMOVE_CORE_PLUGINS=httprpc
 RU_HTTP_USER_AGENT=Mozilla/5.0 (Windows NT 6.0; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0