From 90697cdb623a2eb37810a8ed1811f41682ae0b67 Mon Sep 17 00:00:00 2001
From: Paul Kloppers <kloppers101@gmail.com>
Date: Tue, 21 Apr 2026 20:36:27 +0200
Subject: [PATCH] Run world archive via docker exec

Stream tar from inside the container to the host, so all server
interaction (rcon + archive) happens through docker exec. Requires
the container to be running; fails fast otherwise.
---
 backup.sh | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/backup.sh b/backup.sh
index 325190c..123ef66 100755
--- a/backup.sh
+++ b/backup.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # Usage: ./backup.sh [label]
 # Creates backups/world-YYYY-MM-DD-HHMM[-label].tar.gz
-# If the minecraft container is running, flushes world via rcon first.
+# Requires the minecraft container to be running.
 set -euo pipefail
 
 cd "$(dirname "$0")"
@@ -13,17 +13,18 @@ OUT="backups/world-${STAMP}${SUFFIX}.tar.gz"
 
 mkdir -p backups
 
-if docker ps --format '{{.Names}}' | grep -qx minecraft; then
-    echo "Server running — flushing world via rcon..."
-    docker exec minecraft rcon-cli save-off >/dev/null
-    docker exec minecraft rcon-cli save-all flush >/dev/null
-    trap 'docker exec minecraft rcon-cli save-on >/dev/null || true' EXIT
-else
-    echo "Server not running — archiving world as-is."
+if ! docker ps --format '{{.Names}}' | grep -qx minecraft; then
+    echo "Error: minecraft container is not running." >&2
+    exit 1
 fi
 
-echo "Archiving data/world -> ${OUT}"
-tar -czf "${OUT}" -C data world
+echo "Flushing world via rcon..."
+docker exec minecraft rcon-cli save-off >/dev/null
+docker exec minecraft rcon-cli save-all flush >/dev/null
+trap 'docker exec minecraft rcon-cli save-on >/dev/null || true' EXIT
+
+echo "Archiving /data/world -> ${OUT}"
+docker exec minecraft tar -czf - -C /data world > "${OUT}"
 
 echo "Done."
 ls -lh "${OUT}"