Converted TYPE=FORGE to use image helper

Dockerfile

@@ -60,7 +60,7 @@ RUN easy-add --var os=${TARGETOS} --var arch=${TARGETARCH}${TARGETVARIANT} \
  --var version=0.1.1 --var app=maven-metadata-release --file {{.app}} \
  --from https://github.com/itzg/{{.app}}/releases/download/{{.version}}/{{.app}}_{{.version}}_{{.os}}_{{.arch}}.tar.gz
 
-ARG MC_HELPER_VERSION=1.9.0
+ARG MC_HELPER_VERSION=1.9.2
 ARG MC_HELPER_BASE_URL=https://github.com/itzg/mc-image-helper/releases/download/v${MC_HELPER_VERSION}
 RUN curl -fsSL ${MC_HELPER_BASE_URL}/mc-image-helper-${MC_HELPER_VERSION}.tgz \
     | tar -C /usr/share -zxf - \

examples/.gitignore

@@ -0,0 +1 @@
+/data/

examples/docker-compose-forge.yml

@@ -2,15 +2,16 @@ version: "3.8"
 
 services:
   mc:
-    image: itzg/minecraft-server:java8
+    image: itzg/minecraft-server
     ports:
     # expose the Minecraft server port outside of container
-    - 25565:25565
+    - "25565:25565"
     environment:
       # REQUIRED for all types
       EULA: "TRUE"
       # Set server type (vs the default of vanilla)
       TYPE: FORGE
+      DEBUG: "true"
     volumes:
     # use a named, managed volume for data volume
     - mc_forge:/data

start-deployForge

@@ -1,7 +1,9 @@
 #!/bin/bash
 
-. ${SCRIPTS:-/}start-utils
-: ${FORGEVERSION:=RECOMMENDED}
+: "${FORGEVERSION:=RECOMMENDED}"
+
+# shellcheck source=start-utils
+. "${SCRIPTS:-$(dirname "$0")}/start-utils"
 isDebugging && set -x
 
 get_installer() {
@@ -16,7 +18,7 @@ get_installer() {
     for fn in $forgeFileNames; do
       downloadUrl=https://maven.minecraftforge.net/net/minecraftforge/forge/$fn
       log "...trying $downloadUrl"
-      if curl -o $FORGE_INSTALLER -fsSL $downloadUrl; then
+      if get -o "$FORGE_INSTALLER" "$downloadUrl"; then
         return
       fi
     done
@@ -24,7 +26,7 @@ get_installer() {
     exit 2
  else
     log "Downloading $FORGE_INSTALLER_URL ..."
-    if ! curl -o $FORGE_INSTALLER -fsSL $FORGE_INSTALLER_URL; then
+    if ! get -o "$FORGE_INSTALLER" "$FORGE_INSTALLER_URL"; then
       log "Failed to download from given location $FORGE_INSTALLER_URL"
       exit 2
     fi
@@ -32,20 +34,19 @@ get_installer() {
 }
 
 install() {
-  if [ ! -e $FORGE_INSTALLER ]; then
-    get_installer $normForgeVersion $shortForgeVersion
+  if [ ! -e "$FORGE_INSTALLER" ]; then
+    get_installer "$normForgeVersion" "$shortForgeVersion"
   fi
 
   log "Installing Forge $shortForgeVersion using $FORGE_INSTALLER"
   mkdir -p mods
   tries=3
   while ((--tries >= 0)); do
-    java -jar $FORGE_INSTALLER --installServer
-    if [ $? == 0 ]; then
+    if java -jar "$FORGE_INSTALLER" --installServer; then
       break
     fi
   done
-  if (($tries < 0)); then
+  if ((tries < 0)); then
     log "Forge failed to install after several tries." >&2
     exit 10
   fi
@@ -66,7 +67,7 @@ install() {
 
   export SERVER=$latest
   log "Using server $SERVER"
-  echo $SERVER > $installMarker
+  echo "$SERVER" > "$installMarker"
 }
 
 resolve_versions() {
@@ -81,15 +82,21 @@ resolve_versions() {
     esac
 
     #################################################################################
+    promosUrl=http://files.minecraftforge.net/maven/net/minecraftforge/forge/promotions_slim.json
 
     log "Checking Forge version information."
     case $FORGEVERSION in
+      LATEST)
+        if ! FORGE_VERSION=$(get --json-path ".promos['$VANILLA_VERSION-latest']" "$promosUrl"); then
+          log "ERROR: Version $VANILLA_VERSION is not supported by Forge"
+          log "       Refer to http://files.minecraftforge.net/ for supported versions"
+          exit 2
+        fi
+        ;;
+
       RECOMMENDED)
-        curl -fsSL -o /tmp/forge.json http://files.minecraftforge.net/maven/net/minecraftforge/forge/promotions_slim.json
-        FORGE_VERSION=$(cat /tmp/forge.json | jq -r ".promos[\"$VANILLA_VERSION-recommended\"]")
-        if [ $FORGE_VERSION = null ]; then
-          FORGE_VERSION=$(cat /tmp/forge.json | jq -r ".promos[\"$VANILLA_VERSION-latest\"]")
-          if [ $FORGE_VERSION = null ]; then
+        if ! FORGE_VERSION=$(get --json-path ".promos['$VANILLA_VERSION-recommended']" "$promosUrl"); then
+          if ! FORGE_VERSION=$(get --json-path ".promos['$VANILLA_VERSION-latest']" "$promosUrl"); then
             log "ERROR: Version $VANILLA_VERSION is not supported by Forge"
             log "       Refer to http://files.minecraftforge.net/ for supported versions"
             exit 2
@@ -122,14 +129,15 @@ resolve_versions
 
 installMarker="/data/.forge-installed-$shortForgeVersion"
 
-if [ ! -e $installMarker ]; then
+if [ ! -e "$installMarker" ]; then
   install
 else
-  export SERVER=$(cat $installMarker)
+  SERVER=$(cat "$installMarker")
+  export SERVER
   if [ ! -e "$SERVER" ] && versionLessThan 1.17; then
     rm "$installMarker"
     install
   fi
 fi
 
-exec ${SCRIPTS:-/}start-setupWorld $@
+exec "${SCRIPTS:-$(dirname "$0")}/start-setupWorld" "$@"