feat: support container restarts (#300)

Author: Djaytan

src/runtime/start.sh

@@ -10,6 +10,15 @@ CONFIG_DIR="${SCRIPT_DIR}/config"
 OVERRIDES_CONFIG_DIR="${CONFIG_DIR}/overrides"
 CUE_DIR="${CONFIG_DIR}/cue"
 
+IS_SERVER_RESTART=false
+
+if [ ! -d "${CUE_DIR}" ]; then
+  echo '🔄 Restarting PaperMC server...'
+  IS_SERVER_RESTART=true
+else
+  echo '🚀 Starting PaperMC server for the first time...'
+fi
+
 ## JVM arguments
 # server.properties: https://minecraft.wiki/w/Server.properties
 # bukkit.yml: https://bukkit.fandom.com/wiki/Bukkit.yml
@@ -63,52 +72,55 @@ SERVER_ARGS="
 
 cd "${ROOT_DIR}"
 
-echo '⚙️ Preparing PaperMC server configuration files...'
-
-TMP="$(envsubst '$EULA' < eula.txt)"
-echo "${TMP}" > eula.txt
-echo '🧾 File eula.txt processed'
-
-# TODO: support help.yml
-# TODO: support ops.json
-# TODO: support whitelist.json
-# TODO: disable permissions.yml?
-# TODO: support custom Spark plugin version
-# TODO: Ensure Timings v2 is disabled by default
-# TODO: add tests verifying properties are well customized as expected
-
-if [ -d "${OVERRIDES_CONFIG_DIR}" ] && [ -n "$(find "${OVERRIDES_CONFIG_DIR}" -maxdepth 1 -type f \( -name '*.yml' -o -name '*.yaml' \))" ]; then
-  echo "📝 Custom YAML overrides configuration files have been found in ${OVERRIDES_CONFIG_DIR}."
-  echo '📥 Importing them...'
-  cd "${OVERRIDES_CONFIG_DIR}"
-  cue import --package paper --outfile "${CUE_DIR}/overrides.cue" --ext yml --ext yaml
-else
-  echo "ℹ️ No custom YAML overrides configuration files found in ${OVERRIDES_CONFIG_DIR}."
+if [ "${IS_SERVER_RESTART}" = false ]; then
+  echo '⚙️ Preparing PaperMC server configuration files...'
+
+  # shellcheck disable=SC2016  # Use single quotes to prevent variable expansion with envsubst
+  TMP="$(envsubst '$EULA' < eula.txt)"
+  echo "${TMP}" > eula.txt
+  echo '🧾 File eula.txt processed.'
+
+  # TODO: support help.yml
+  # TODO: support ops.json
+  # TODO: support whitelist.json
+  # TODO: disable permissions.yml?
+  # TODO: support custom Spark plugin version
+  # TODO: Ensure Timings v2 is disabled by default
+  # TODO: add tests verifying properties are well customized as expected
+
+  if [ -d "${OVERRIDES_CONFIG_DIR}" ] && [ -n "$(find "${OVERRIDES_CONFIG_DIR}" -maxdepth 1 -type f \( -name '*.yml' -o -name '*.yaml' \))" ]; then
+    echo "📝 Custom YAML overrides configuration files have been found in ${OVERRIDES_CONFIG_DIR}."
+    echo '📥 Importing them...'
+    cd "${OVERRIDES_CONFIG_DIR}"
+    cue import --package paper --outfile "${CUE_DIR}/overrides.cue" --ext yml --ext yaml
+  else
+    echo "ℹ️ No custom YAML overrides configuration files found in ${OVERRIDES_CONFIG_DIR}."
+  fi
+
+  cd "${CUE_DIR}"
+
+  # Validate configuration values
+  # TODO: more execution trace messages
+  cue vet --concrete
+
+  # Generate the configuration files
+  ENVVAR="$(env | grep -E '^(BUKKIT_|SPIGOT_|PAPER_)' | tr '\n' ',' | head -c -1)"
+
+  echo "📦 Generating configuration files..."
+  cue export --inject "${ENVVAR}" -e 'bukkit.global' --out yaml --outfile "${ROOT_DIR}/bukkit.yml"
+  cue export --inject "${ENVVAR}" -e 'bukkit.commands' --out yaml --outfile "${CONFIG_DIR}/commands.yml"
+  cue export --inject "${ENVVAR}" -e 'bukkit.permissions' --out yaml --outfile "${CONFIG_DIR}/permissions.yml"
+  cue export --inject "${ENVVAR}" -e 'spigot' --out yaml --outfile "${CONFIG_DIR}/spigot.yml"
+  cue export --inject "${ENVVAR}" -e 'paper.global' --out yaml --outfile "${CONFIG_DIR}/paper-global.yml"
+  cue export --inject "${ENVVAR}" -e 'paper["worlds-defaults"]' --out yaml --outfile "${CONFIG_DIR}/paper-world-defaults.yml"
+  echo '✅  Configuration files successfully generated!'
+
+  # Clean-up CUE files after config generation
+  rm -rf "${CUE_DIR}"
+
+  echo '✨  PaperMC server ready to start!'
 fi
 
-cd "${CUE_DIR}"
-
-# Validate configuration values
-# TODO: more execution trace messages
-cue vet --concrete
-
-# Generate the configuration files
-ENVVAR="$(env | grep -E '^(BUKKIT_|SPIGOT_|PAPER_)' | tr '\n' ',' | head -c -1)"
-
-echo "📦 Generating configuration files..."
-cue export --inject "${ENVVAR}" -e 'bukkit.global' --out yaml --outfile "${ROOT_DIR}/bukkit.yml"
-cue export --inject "${ENVVAR}" -e 'bukkit.commands' --out yaml --outfile "${CONFIG_DIR}/commands.yml"
-cue export --inject "${ENVVAR}" -e 'bukkit.permissions' --out yaml --outfile "${CONFIG_DIR}/permissions.yml"
-cue export --inject "${ENVVAR}" -e 'spigot' --out yaml --outfile "${CONFIG_DIR}/spigot.yml"
-cue export --inject "${ENVVAR}" -e 'paper.global' --out yaml --outfile "${CONFIG_DIR}/paper-global.yml"
-cue export --inject "${ENVVAR}" -e 'paper["worlds-defaults"]' --out yaml --outfile "${CONFIG_DIR}/paper-world-defaults.yml"
-echo '✅  Configuration files successfully generated!'
-
-# Clean-up CUE files after config generation
-rm -rf "${CUE_DIR}"
-
 cd "${ROOT_DIR}"
 
-echo '✨  PaperMC server ready to start!'
-
 exec java $JVM_ARGUMENTS -jar "${SCRIPT_DIR}"/papermc-server-*.jar $SERVER_ARGS