add docker container secret management via env

Dockerfile

@@ -32,9 +32,12 @@ VOLUME ${DATA_PATH}
 
 
 ENV MEMORY=4G
+ENV PROXY_SECRET=change_me
 
 WORKDIR ${WORKDIR_PATH}/config
 
 EXPOSE 25565/tcp
 
-CMD java -Xms${MEMORY} -Xmx${MEMORY} -jar *.jar -nogui
+CMD \
+    sed -i "s/_PROXY_SECRET_/${PROXY_SECRET}/g" config/paper-global.yml && \
+    java -Xms${MEMORY} -Xmx${MEMORY} -jar *.jar -nogui

src/config/paper-global.yml

@@ -95,9 +95,9 @@ proxies:
     online-mode: true
   proxy-protocol: false
   velocity:
-    enabled: false
-    online-mode: true
-    secret: ''
+    enabled: true
+    online-mode: false
+    secret: '_PROXY_SECRET_'
 scoreboards:
   save-empty-scoreboard-teams: true
   track-plugin-scoreboards: false

src/server.properties

@@ -35,7 +35,7 @@ max-tick-time=60000
 max-world-size=29999984
 motd=A Minecraft Server
 network-compression-threshold=256
-online-mode=true
+online-mode=false
 op-permission-level=4
 player-idle-timeout=0
 prevent-proxy-connections=false