Regenerate map on schedule

Dockerfile

@@ -21,6 +21,7 @@ ENV RENDER_POI "true"
 ENV RENDER_SIGNS_FILTER "-- RENDER --"
 ENV RENDER_SIGNS_HIDE_FILTER "false"
 ENV RENDER_SIGNS_JOINER "<br />"
+ENV REFRESH_DURATION 0
 
 # ---------------------------- #
 # INSTALL & CONFIGURE DEFAULTS #

README.md

@@ -57,3 +57,5 @@ _Note:_ The `latest` Docker tag is rebuilt daily. If there are changes to the [u
 
 - `RENDER_SIGNS_JOINER`
   Default Value: `<br />`. Set to the string that should be used to join the lines on the sign while rendering. Value of `"<br />"` will make each in-game line it's own line on the render. A value of `" "` will make all the in-game lines a single line on the render.
+- `REFRESH_DURATION`
+  Default Value: `0`. Set to a number to regenerate the map every `REFRESH_DURATION` seconds. Disabled if set to `0`.

entrypoint.sh

@@ -1,6 +1,22 @@
 #!/bin/bash
 set -o errexit
 
+render_map() {
+  # Render the Map
+  if [ "$RENDER_MAP" == "true" ]; then
+    # (We disable to support passing multiple arguments)
+    # shellcheck disable=SC2086
+    overviewer.py --config "$CONFIG_LOCATION" $ADDITIONAL_ARGS
+  fi
+
+  # Render the POI
+  if [ "$RENDER_POI" == "true" ]; then
+  # (We disable to support passing multiple arguments)
+    # shellcheck disable=SC2086
+    overviewer.py --config "$CONFIG_LOCATION" --genpoi $ADDITIONAL_ARGS_POI
+  fi
+}
+
 # Require MINECRAFT_VERSION environment variable to be set (no default assumed)
 if [ -z "$MINECRAFT_VERSION" ]; then
   echo "Expecting environment variable MINECRAFT_VERSION to be set to non-empty string. Exiting."
@@ -30,16 +46,12 @@ else
     echo "Download complete."
 fi
 
-# Render the Map
-if [ "$RENDER_MAP" == "true" ]; then
-  # (We disable to support passing multiple arguments)
-  # shellcheck disable=SC2086
-  overviewer.py --config "$CONFIG_LOCATION" $ADDITIONAL_ARGS
-fi
-
-# Render the POI
-if [ "$RENDER_POI" == "true" ]; then
-# (We disable to support passing multiple arguments)
-  # shellcheck disable=SC2086
-  overviewer.py --config "$CONFIG_LOCATION" --genpoi $ADDITIONAL_ARGS_POI
-fi
+# Render the map, either once if REFRESH_DURATION is 0, or every REFRESH_DURATION seconds
+if [ $REFRESH_DURATION -gt 0 ]; then
+  while true; do
+    render_map
+    sleep $REFRESH_DURATION
+  done
+else
+  render_map
+fi