Update Dockerfile

Dockerfile

@@ -30,15 +30,17 @@ EXPOSE 25565
 
 # launcher script: start tunnel, wait for tcp url, print it, then run server
 RUN printf '%s\n' \
-    '#!/bin/sh' \
-    'set -e' \
-    'cloudflared tunnel --url tcp://localhost:25565 --no-autoupdate --logfile /tmp/cf.log &' \
-    'CF_PID=$!' \
-    'echo "waiting for cloudflared…"' \
-    'while ! grep -m1 "tcp://" /tmp/cf.log >/dev/null 2>&1; do sleep 1; done' \
-    'MC_URL=$(grep -m1 "tcp://" /tmp/cf.log | sed -n "s/.*\(tcp:\/\/[^ ]*\).*/\1/p")' \
-    'echo "minecraft public endpoint: $MC_URL"' \
-    'exec java -Xmx2G -Xms2G -jar /minecraft/server.jar --nogui' \
-    > /start.sh && chmod +x /start.sh
+  '#!/bin/sh' \
+  'set -e' \
+  'cloudflared tunnel --url tcp://localhost:25565 --no-autoupdate --logfile /tmp/cf.log --logformat json &' \
+  'echo "waiting for cloudflared…"' \
+  'while true; do' \
+  '  MC_URL=$(grep -o "tcp://[A-Za-z0-9._-]*trycloudflare.com:[0-9]*" /tmp/cf.log | head -n1)' \
+  '  [ -n "$MC_URL" ] && break' \
+  '  sleep 1' \
+  'done' \
+  'echo "minecraft public endpoint: $MC_URL"' \
+  'exec java -Xmx2G -Xms2G -jar /minecraft/server.jar --nogui' \
+  > /start.sh && chmod +x /start.sh
 
 CMD ["/start.sh"]