fank · Nov 2, 2026 · Nov 2, 2026 · Nov 2, 2026
diff --git a/README.md b/README.md
@@ -65,9 +65,11 @@ docker logs factorio
 Stop the server:
 
 ```shell
-docker stop factorio
+docker stop --timeout 120 factorio
 ```
 
+Allow enough time for the world to save before Docker sends SIGKILL. Increase the timeout for large saves; with Compose, configure `stop_grace_period` instead.
+
 Now there's a `server-settings.json` file in the folder `/opt/factorio/config`. Modify this to your liking and restart the server:
 
 ```shell
@@ -114,7 +116,7 @@ Now run the server as before. In about a minute the new version of Factorio shou
 
 ### Saves
 
-A new map named `_autosave1.zip` is generated the first time the server is started. The `map-gen-settings.json` and `map-settings.json` files in `/opt/factorio/config` are used for the map settings. On subsequent runs the newest save is used.
+A new map named `_autosave1.zip` (or `SAVE_NAME` when set) is generated the first time the server is started. The `map-gen-settings.json` and `map-settings.json` files in `/opt/factorio/config` are used for the map settings. On subsequent runs the newest save is used.
 
 To load an old save stop the server and run the command `touch oldsave.zip`. This resets the date. Then restart the server. Another option is to delete all saves except one.
 
@@ -124,7 +126,7 @@ To generate a new map stop the server, delete all of the saves and restart the s
 
 You can specify a specific save to load by configuring the server through a set of environment variables:
 
-To load an existing save set `SAVE_NAME` to the name of your existing save file located within the `saves` directory, without the `.zip` extension:
+To load an existing save, set `SAVE_NAME` to its name in the `saves` directory, with or without `.zip`, or to an absolute file path. The same path is used for generation and subsequent starts. A missing selected save produces an error rather than loading another world:
 
 ```shell
 sudo docker run -d \
@@ -312,6 +314,8 @@ These are the environment variables which can be specified at container run time
 
 **Note:** All environment variables are compared as strings. Quote YAML mapping values, for example `DLC_SPACE_AGE: "false"`. In list syntax, quote the whole item (`- "DLC_SPACE_AGE=elevated-rails"`), not only the value: `- DLC_SPACE_AGE="elevated-rails"` passes literal quotation marks to the container.
 
+An explicit port in `BIND` overrides `PORT`, for example `127.0.0.1:34201` or `[::1]:34201`. A bare IPv6 address still uses `PORT`.
+
 #### Host file ownership
 
 The regular image starts as root, adjusts ownership inside `/factorio`, and runs the server as `PUID:PGID` (845:845 by default). To keep a bind-mounted data directory owned by your host user, set these to the numeric output of `id -u` and `id -g`. Changing them changes ownership of the mounted data, so use a dedicated directory—not your entire home directory.

diff --git a/docker/Dockerfile b/docker/Dockerfile
@@ -45,7 +45,7 @@ ENV PORT=34197 \
 SHELL ["/bin/bash", "-eo", "pipefail", "-c"]
 
 RUN apt-get -q update \
-    && DEBIAN_FRONTEND=noninteractive apt-get -qy install ca-certificates curl jq pwgen xz-utils procps gettext-base file --no-install-recommends \
+    && DEBIAN_FRONTEND=noninteractive apt-get -qy install ca-certificates curl jq pwgen xz-utils procps gettext-base file util-linux --no-install-recommends \
     && if [[ "$(uname -m)" == "aarch64" && -z "${SHA256_ARM64}" ]]; then \
         echo "installing ARM compatability layer" \
         && DEBIAN_FRONTEND=noninteractive apt-get -qy install unzip --no-install-recommends \ 

diff --git a/docker/files/docker-entrypoint-rootless.sh b/docker/files/docker-entrypoint-rootless.sh
@@ -67,26 +67,32 @@ sed -i '/write-data=/c\write-data=\/factorio/' /opt/factorio/config/config.ini
 NRSAVES=$(find -L "$SAVES" -iname \*.zip -mindepth 1 | wc -l)
 if [[ $GENERATE_NEW_SAVE != true && $NRSAVES ==  0 ]]; then
     GENERATE_NEW_SAVE=true
-    SAVE_NAME=_autosave1
+    SAVE_NAME="${SAVE_NAME:-_autosave1}"
+fi
+
+if [[ "$SAVE_NAME" == /* ]]; then
+    SAVE_FILE="$SAVE_NAME"
+else
+    SAVE_FILE="$SAVES/${SAVE_NAME%.zip}.zip"
 fi
 
 if [[ $GENERATE_NEW_SAVE == true ]]; then
     if [[ -z "$SAVE_NAME" ]]; then
         echo "If \$GENERATE_NEW_SAVE is true, you must specify \$SAVE_NAME"
         exit 1
     fi
-    if [[ -f "$SAVES/$SAVE_NAME.zip" ]]; then
-        echo "Map $SAVES/$SAVE_NAME.zip already exists, skipping map generation"
+    if [[ -f "$SAVE_FILE" ]]; then
+        echo "Map $SAVE_FILE already exists, skipping map generation"
     else
         if [[ -n "$PRESET" ]]; then
             $EXEC /opt/factorio/bin/x64/factorio \
-                --create "$SAVES/$SAVE_NAME.zip" \
+                --create "$SAVE_FILE" \
                 --preset "$PRESET" \
                 --map-gen-settings "$CONFIG/map-gen-settings.json" \
                 --map-settings "$CONFIG/map-settings.json"
         else
             $EXEC /opt/factorio/bin/x64/factorio \
-                --create "$SAVES/$SAVE_NAME.zip" \
+                --create "$SAVE_FILE" \
                 --map-gen-settings "$CONFIG/map-gen-settings.json" \
                 --map-settings "$CONFIG/map-settings.json"
         fi
@@ -95,7 +101,6 @@ fi
 
 # Build command flags
 FLAGS=(\
-  --port "$PORT" \
   --server-settings "$SERVER_SETTINGS_FILE" \
   --server-banlist "$SERVER_BANLIST_FILE" \
   --rcon-port "$RCON_PORT" \
@@ -115,10 +120,19 @@ if [ -n "$BIND" ]; then
   FLAGS+=( --bind "$BIND" )
 fi
 
+# An explicit bind port wins; bare IPv6 addresses still use PORT.
+if [[ ! "$BIND" =~ ^[^:]+:[0-9]+$ && ! "$BIND" =~ ^\[[^]]+\]:[0-9]+$ ]]; then
+  FLAGS+=( --port "$PORT" )
+fi
+
 if [[ $LOAD_LATEST_SAVE == true ]]; then
     FLAGS+=( --start-server-load-latest )
 else
-    FLAGS+=( --start-server "$SAVE_NAME" )
+    if [[ -z "$SAVE_NAME" || ! -f "$SAVE_FILE" ]]; then
+        echo "Selected save does not exist: $SAVE_FILE. Set SAVE_NAME or GENERATE_NEW_SAVE=true." >&2
+        exit 1
+    fi
+    FLAGS+=( --start-server "$SAVE_FILE" )
 fi
 
 # Execute factorio

diff --git a/docker/files/docker-entrypoint.sh b/docker/files/docker-entrypoint.sh
@@ -56,8 +56,8 @@ if [[ $(id -u) == 0 ]]; then
   groupmod -o -g "$PGID" factorio
   # Take ownership of factorio data if running as root
   chown -R factorio:factorio "$FACTORIO_VOL"
-  # Drop to the factorio user
-  EXEC="runuser -u factorio -g factorio --"
+  # Replace the process when dropping privileges; runuser kills slow saves after SIGTERM.
+  EXEC="setpriv --reuid=factorio --regid=factorio --init-groups --"
 fi
 
 # Setup ARM64 emulation support
@@ -69,34 +69,39 @@ sed -i '/write-data=/c\write-data=\/factorio/' /opt/factorio/config/config.ini
 NRSAVES=$(find -L "$SAVES" -iname \*.zip -mindepth 1 | wc -l)
 if [[ $GENERATE_NEW_SAVE != true && $NRSAVES ==  0 ]]; then
     GENERATE_NEW_SAVE=true
-    SAVE_NAME=_autosave1
+    SAVE_NAME="${SAVE_NAME:-_autosave1}"
+fi
+
+if [[ "$SAVE_NAME" == /* ]]; then
+    SAVE_FILE="$SAVE_NAME"
+else
+    SAVE_FILE="$SAVES/${SAVE_NAME%.zip}.zip"
 fi
 
 if [[ $GENERATE_NEW_SAVE == true ]]; then
     if [[ -z "$SAVE_NAME" ]]; then
         echo "If \$GENERATE_NEW_SAVE is true, you must specify \$SAVE_NAME"
         exit 1
     fi
-    if [[ -f "$SAVES/$SAVE_NAME.zip" ]]; then
-        echo "Map $SAVES/$SAVE_NAME.zip already exists, skipping map generation"
+    if [[ -f "$SAVE_FILE" ]]; then
+        echo "Map $SAVE_FILE already exists, skipping map generation"
     else
         if [[ -n "$PRESET" ]]; then
             $EXEC /opt/factorio/bin/x64/factorio \
-                --create "$SAVES/$SAVE_NAME.zip" \
+                --create "$SAVE_FILE" \
                 --preset "$PRESET" \
                 --map-gen-settings "$CONFIG/map-gen-settings.json" \
                 --map-settings "$CONFIG/map-settings.json"
         else
             $EXEC /opt/factorio/bin/x64/factorio \
-                --create "$SAVES/$SAVE_NAME.zip" \
+                --create "$SAVE_FILE" \
                 --map-gen-settings "$CONFIG/map-gen-settings.json" \
                 --map-settings "$CONFIG/map-settings.json"
         fi
     fi
 fi
 
 FLAGS=(\
-  --port "$PORT" \
   --server-settings "$SERVER_SETTINGS_FILE" \
   --server-banlist "$SERVER_BANLIST_FILE" \
   --rcon-port "$RCON_PORT" \
@@ -116,10 +121,19 @@ if [ -n "$BIND" ]; then
   FLAGS+=( --bind "$BIND" )
 fi
 
+# An explicit bind port wins; bare IPv6 addresses still use PORT.
+if [[ ! "$BIND" =~ ^[^:]+:[0-9]+$ && ! "$BIND" =~ ^\[[^]]+\]:[0-9]+$ ]]; then
+  FLAGS+=( --port "$PORT" )
+fi
+
 if [[ $LOAD_LATEST_SAVE == true ]]; then
     FLAGS+=( --start-server-load-latest )
 else
-    FLAGS+=( --start-server "$SAVE_NAME" )
+    if [[ -z "$SAVE_NAME" || ! -f "$SAVE_FILE" ]]; then
+        echo "Selected save does not exist: $SAVE_FILE. Set SAVE_NAME or GENERATE_NEW_SAVE=true." >&2
+        exit 1
+    fi
+    FLAGS+=( --start-server "$SAVE_FILE" )
 fi
 
 # shellcheck disable=SC2086

diff --git a/docker/files/scenario.sh b/docker/files/scenario.sh
@@ -45,6 +45,7 @@ source "${INSTALLED_DIRECTORY}/setup-exec.sh"
 exec $EXEC /opt/factorio/bin/x64/factorio \
   --port "$PORT" \
   --start-server-load-scenario "$SERVER_SCENARIO" \
+  --mod-directory "$MODS" \
   --preset "$PRESET" \
   --map-gen-settings "$CONFIG/map-gen-settings.json" \
   --map-settings "$CONFIG/map-settings.json" \

diff --git a/docker/files/scenario2map.sh b/docker/files/scenario2map.sh
@@ -27,10 +27,13 @@ if [[ ! -f $CONFIG/map-settings.json ]]; then
   cp /opt/factorio/data/map-settings.example.json "$CONFIG/map-settings.json"
 fi
 
+"${INSTALLED_DIRECTORY}"/docker-dlc.sh
+
 # Setup ARM64 emulation support
 EXEC=""
 # shellcheck disable=SC1091
 source "${INSTALLED_DIRECTORY}/setup-exec.sh"
 
 exec $EXEC /opt/factorio/bin/x64/factorio \
-  --scenario2map "$SERVER_SCENARIO"
+  --scenario2map "$SERVER_SCENARIO" \
+  --mod-directory "$MODS"
diff --git a/tests/test_config_paths.py b/tests/test_config_paths.py
@@ -163,7 +163,8 @@ def test_scenario_conversion_uses_custom_settings(self):
         settings = self.work / "conversion" / "settings.json"
         self.run_script("scenario2map.sh", {"SERVER_SETTINGS_FILE": str(settings)})
         self.assertEqual(json.loads(settings.read_text()), self.example)
-        self.assertEqual(json.loads(self.calls.read_text()), ["--scenario2map", "freeplay"])
+        self.assertEqual(json.loads(self.calls.read_text()),
+                         ["--scenario2map", "freeplay", "--mod-directory", self.env["MODS"]])
 
 
 if __name__ == "__main__":