Support migrate from an existing server

migration/README.md

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+# Migrate From Existing Server
+
+## Using the script
+
+> [!WARNING]
+> Use this script at your own risk, I am not responsible for dataloss!
+>
+> Please make sure you always have a backup!
+
+1. Find a directory which is named by game server name and contains all saved game data,
+   usually it will at `~/Steam/steamapps/common/PalServer/Pal/Saved/SaveGames/0/`
+2. Make sure `migration/migrate.sh`, saved game data directory and mounted volume
+   (e.g. `palworld/`) are in the same directory. Like this:
+
+    ```shell
+    ubuntu@VM-4-5-ubuntu:~/test-pal-migrate$ ll
+    total 24
+    drwxrwxr-x  4 ubuntu ubuntu 4096 Jan 26 03:31 ./
+    drwxr-x--- 12 ubuntu ubuntu 4096 Jan 26 03:31 ../
+    drwxr-xr-x  2 ubuntu ubuntu 4096 Jan 26 03:30 74406BE1D7B54114AA5984CCF1236865/
+    -rw-r--r--  1 ubuntu ubuntu  840 Jan 25 05:51 docker-compose.yml
+    -rw-rw-r--  1 ubuntu ubuntu  848 Jan 26 03:31 migrate.sh
+    drwxrwxr-x  7 ubuntu ubuntu 4096 Jan 26 03:31 palworld/
+    ```
+
+3. Run `migrate.sh` like this
+
+    ```shell
+    ./migrate.sh {CONTAINER_NAME} {SERVER_NAME}
+    ```
+
+   For example,
+
+    ```shell
+    ./migrate.sh test-pal-migrate 74406BE1D7B54114AA5984CCF1236865
+    ```
+
+## Manually
+
+1. Copy the save from your old dedicated server to your new dedicated server.
+2. In the `PalServer\Pal\Saved\Config\LinuxServer\GameUserSettings.ini` file of the **new** server,
+   change the `DedicatedServerName` to match your save's folder name. For example,
+   if your save's folder name is `2E85FD38BAA792EB1D4C09386F3A3CDA`, the DedicatedServerName changes to
+   DedicatedServerName=`2E85FD38BAA792EB1D4C09386F3A3CDA`.
+3. Delete the entire new server save at `PalServer\Pal\Saved\SaveGames\0\<your_save_here>`,
+   and replace it with the folder from the old server.
+4. Restart the new server

migration/migrate.sh

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+#!/bin/bash
+set -e
+
+CONTAINER_NAME=$1
+MIGRATION_SERVER_NAME=$2
+
+if [ ! -d ./"${MIGRATION_SERVER_NAME}" ]; then
+  echo "can not find ${MIGRATION_SERVER_NAME} dir at current dir"
+  exit 1
+fi
+
+if [ ! -d ./palworld ]; then
+  echo "can not find palworld dir at current dir"
+  exit 1
+fi
+
+CONTAINER_ID=$(docker ps --filter name="${CONTAINER_NAME}" --format '{{.ID}}')
+
+echo "########## STOPPING CONTAINER ${CONTAINER_NAME} NOW ##########"
+docker stop "${CONTAINER_ID}"
+
+cp -r ./"${MIGRATION_SERVER_NAME}" ./palworld/Pal/Saved/SaveGames/0/"${MIGRATION_SERVER_NAME}"/
+
+sed -i "s/DedicatedServerName=.*/DedicatedServerName=${MIGRATION_SERVER_NAME}/" ./palworld/Pal/Saved/Config/LinuxServer/GameUserSettings.ini
+
+echo "########## STARTING CONTAINER ${CONTAINER_NAME} NOW ##########"
+docker start "${CONTAINER_ID}"
+
+