By default, generate random RCON password at startup (#2071)

Dockerfile

@@ -58,7 +58,7 @@ WORKDIR /data
 STOPSIGNAL SIGTERM
 
 # End user MUST set EULA and change RCON_PASSWORD
-ENV TYPE=VANILLA VERSION=LATEST EULA="" UID=1000 GID=1000 RCON_PASSWORD=minecraft
+ENV TYPE=VANILLA VERSION=LATEST EULA="" UID=1000 GID=1000
 
 COPY --chmod=755 scripts/start* /
 COPY --chmod=755 bin/ /usr/local/bin/

README.md

@@ -1188,9 +1188,9 @@ The server icon which has been set doesn't get overridden by default. It can be
 
 RCON is **enabled by default** to allow for graceful shut down the server and coordination of save state during backups. RCON can be disabled by setting `ENABLE_RCON` to "false".
 
-The default password is "minecraft" but **change the password before deploying into production** by setting `RCON_PASSWORD`.
+The RCON password can be set via `RCON_PASSWORD` or the name of a file that contains the password can be referenced by setting `RCON_PASSWORD_FILE`. If not set, a random password will be generated at each startup.
 
-**DO NOT MAP THE RCON PORT EXTERNALLY** unless you aware of all the consequences and have set a **secure password** with `RCON_PASSWORD`. 
+Regardless of the password set or defaulted, **DO NOT MAP THE RCON PORT EXTERNALLY** unless you sure that is what you intended. 
 
 > Mapping ports (`-p` command line or `ports` in compose) outside the container and docker networking needs to be a purposeful choice. Most production Docker deployments do not need any of the Minecraft ports mapped externally from the server itself.
 

scripts/start

@@ -10,10 +10,18 @@
 umask 0002
 chmod g+w /data
 
+if isTrue "${ENABLE_RCON:-true}" && ! [ -v RCON_PASSWORD ] && ! [ -v RCON_PASSWORD_FILE ]; then
+  RCON_PASSWORD=$(openssl rand -hex 12)
+  export RCON_PASSWORD
+fi
+
 if ! isTrue "${SKIP_SUDO:-false}" && [ "$(id -u)" = 0 ]; then
   runAsUser=minecraft
   runAsGroup=minecraft
 
+  # For rcon-cli access running via exec, which by default is running as root
+  echo "password=${RCON_PASSWORD}" > "$HOME/.rcon-cli.env"
+
   if [[ -v UID ]]; then
     if [[ $UID != 0 ]]; then
       if [[ $UID != $(id -u minecraft) ]]; then

scripts/start-configuration

@@ -83,6 +83,9 @@ if [[ $RCON_PASSWORD_FILE ]]; then
     log ""
 fi
 
+# For rcon-cli access
+echo "password=${RCON_PASSWORD}" > "$HOME/.rcon-cli.env"
+
 function fixJavaPath() {
   # Some Docker management UIs grab all the image declared variables and present them for configuration.
   # When upgrading images across Java versions, that creates a mismatch in PATH's expected by base image.

tests/setuponlytests/defaults/verify.sh

@@ -1,3 +1,2 @@
-mc-image-helper assert propertyEquals --file=server.properties --property=rcon.password --expect=minecraft
 mc-image-helper assert propertyEquals --file=server.properties --property=rcon.port --expect=25575
 mc-image-helper assert propertyEquals --file=server.properties --property=enable-rcon --expect=true