Initial revision: cloudformation template with UserData for calling i…

…n further setup from this repository.

cloudformation_server_stack.yaml

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+AWSTemplateFormatVersion: '2010-09-09'
+Description: AWS CloudFormation Template for a hosted game server
+
+Parameters:
+  ServerPortNumberStart:
+    Type: Number
+    Description: First TCP port for game server traffic
+
+  ServerPortNumberEnd:
+    Type: Number
+    Description: Last TCP port for game server traffic
+
+  SetupCommand:
+    Type: String
+    Description: Defines the setup invocation. Permits code execution. Direct secrets prohibited.
+
+  ExistingVolumeId:
+    Type: String
+    Description: ID of an existing EBS volume to attach. Leave empty to create a new volume.
+    Default: ""
+
+Conditions:
+  CreateNewVolume: !Equals [ !Ref ExistingVolumeId, "" ]
+
+Resources:
+  ServerInstance:
+    Type: AWS::EC2::Instance
+    Properties:
+      InstanceType: t3.large  # 8GB, 2vcpu, 0.1056 USD/hour
+      ImageId: ami-02765a2a1f276edff  # Amazon Linux 2 AMI (HVM) - Kernel 5.10, SSD Volume Type, 64-bit (x86)  /  https://ap-southeast-4.console.aws.amazon.com/ec2/home?region=ap-southeast-4#AMICatalog:
+      KeyName: tim_ssh_to_game_server  # EC2 / key pairs
+      SecurityGroupIds:
+        - !Ref ServerSecurityGroup
+      UserData:
+        Fn::Base64: !Sub |
+          #!/bin/bash
+
+          # Australia/Melbourne should be all that anyone will ever need... right?
+          timedatectl set-timezone Australia/Melbourne
+
+          echo "!! Check whether the attached volume is formatted.."
+          REAL_DEVICE=$(sudo readlink -f /dev/sdf)
+          echo "/dev/sdf maps to $REAL_DEVICE by symlink check"
+          if [ "$(sudo file -s $REAL_DEVICE | awk '{print $2}')" == "data" ]; then
+              echo "$REAL_DEVICE is not formatted, formatting as ext4..."
+              sudo mkfs -t ext4 $REAL_DEVICE
+          else
+              echo "$REAL_DEVICE is already formatted."
+          fi
+
+          echo "!! Mount the attached volume to /mnt/persist"
+          sudo mkdir -p /mnt/persist
+          sudo mount $REAL_DEVICE /mnt/persist
+          echo "$REAL_DEVICE /mnt/persist ext4 defaults,nofail 0 2" | sudo tee -a /etc/fstab > /dev/null
+
+          echo "!! Clone and use AWS-Games"
+          yum install -y git
+          cd /home/ec2-user
+          git clone https://github.com/TSheahan/AWS-Games.git
+          chown -R ec2-user:ec2-user AWS-Games
+          cd AWS-Games
+
+          echo "!! Execute SetupCommand"
+          # as root, invoke the setup command, expecting it to handle system & user setup tasks
+          # use due caution for code execution capability
+          ${SetupCommand}
+
+
+  NewVolume:
+    Type: AWS::EC2::Volume
+    Condition: CreateNewVolume
+    Properties:
+      Size: 10  # Adjust as needed for world files - 1.13GB after 1 months minecraft play
+      VolumeType: gp3
+      AvailabilityZone: !GetAtt ServerInstance.AvailabilityZone
+      Tags:
+        - Key: "Purpose"
+          Value: "GameServerPersistentFiles"
+    DeletionPolicy: Retain
+
+  PersistentVolumeAttachment:
+    Type: AWS::EC2::VolumeAttachment
+    Properties:
+      InstanceId: !Ref ServerInstance
+      VolumeId: !If [CreateNewVolume, !Ref NewVolume, !Ref ExistingVolumeId]
+      Device: /dev/sdf
+
+  ServerEIP:
+    Type: AWS::EC2::EIP
+    Properties:
+      InstanceId: !Ref ServerInstance
+
+  ServerSecurityGroup:
+    Type: AWS::EC2::SecurityGroup
+    Properties:
+      GroupDescription: Allow SSH and game traffic
+      SecurityGroupIngress:
+        - IpProtocol: tcp
+          FromPort: 22
+          ToPort: 22
+          CidrIp: 0.0.0.0/0
+        - IpProtocol: tcp
+          FromPort: !Ref ServerPortNumberStart  # Destination port range start
+          ToPort: !Ref ServerPortNumberEnd      # Destination port range end
+          CidrIp: 0.0.0.0/0
+
+Outputs:
+  ServerIP:
+    Description: IP Address of the server
+    Value: !Ref ServerEIP
+  ServerPortStart:
+    Description: First TCP port used for the server
+    Value: !Ref ServerPortNumberStart
+  ServerPortEnd:
+    Description: Last TCP port used for the server
+    Value: !Ref ServerPortNumberEnd
+  SetupCommand:
+    Description: Displays the SetupCommand which was used at instance instantiation
+    Value: !Ref SetupCommand
+  NewVolumeId:
+    Description: The ID of the newly created EBS volume (if created).
+    Value: !If [ CreateNewVolume, !Ref NewVolume, "" ]
+  ExistingVolumeId:
+    Description: Mirrors the input for optional existing EBS volume ID.
+    Value: !Ref ExistingVolumeId

minecraft/setup.sh

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+#!/bin/env bash
+
+cat <<'EOF'
+======================================================================
+This script sets up a Minecraft server with the following configurations:
+- Server Folder: The directory where the server files are stored.
+- Server Version: The version of the Minecraft server to be deployed.
+  - used to compose jar filename upon download
+- JAR URL: The URL from which the Minecraft server JAR file is downloaded.
+
+Usage:
+minecraft/setup.sh --server-folder=<path> --server-version=<version> --jar-url=<url>
+
+The script is designed to be invoked as root via the UserData script of a
+linux game server instance (defined in a CloudFormation template).
+
+It expects to be executed from the repository root folder.
+
+The SetupCommand parameter must include the needed arguments.
+
+======================================================================
+EOF
+
+if [ ! -d ../AWS-Games ]; then
+  echo "setup must run from repository root"
+  exit 1
+fi
+
+# Initialize variables to hold the values of the arguments
+serverFolder=""
+serverVersion=""
+jarUrl=""
+
+# Error function to display an error message and exit
+error() {
+  echo "Error: $1" >&2
+  echo "Usage: $0 --server-folder=<path> --server-version=<version> --jar-url=<url>" >&2
+  exit 1
+}
+
+# Loop through arguments and process them
+for arg in "$@"
+do
+    case $arg in
+        --server-folder=*)
+        serverFolder="${arg#*=}"
+        ;;
+        --server-version=*)
+        serverVersion="${arg#*=}"
+        ;;
+        --jar-url=*)
+        jarUrl="${arg#*=}"
+        ;;
+        *)
+        # Unknown option
+        error "Unknown argument ${arg}"
+        ;;
+    esac
+done
+
+# Check if any of the required arguments are missing
+if [ -z "$serverFolder" ]; then
+    error "server-folder argument is required"
+fi
+if [ -z "$serverVersion" ]; then
+    error "server-version argument is required"
+fi
+if [ -z "$jarUrl" ]; then
+    error "jar-url argument is required"
+fi
+
+# If all arguments are provided, proceed with the rest of the script
+echo "Server Folder: $serverFolder"
+echo "Server Version: $serverVersion"
+echo "JAR URL: $jarUrl"
+
+
+echo "!! Install JDK"
+yum update -y
+yum install -y java-17-amazon-corretto-devel
+
+echo "!! Check Java version"
+java -version
+
+echo "!! Ensure /mnt/persist/minecraft exists and is owned by ec2-user"
+mkdir -p /mnt/persist/minecraft
+chown ec2-user:ec2-user /mnt/persist/minecraft
+
+echo "!! Ensure the server folder exists and is owned by ec2-user"
+mkdir -p "/mnt/persist/minecraft/${serverFolder}"
+chown ec2-user:ec2-user "/mnt/persist/minecraft/${serverFolder}"
+
+echo "!! Write /etc/systemd/system/minecraft-server.service"
+cat << EOF > /etc/systemd/system/minecraft-server.service
+[Unit]
+Description=Minecraft Server
+After=network.target
+
+[Service]
+User=ec2-user
+WorkingDirectory=/mnt/persist/minecraft/${serverFolder}
+ExecStart=/mnt/persist/minecraft/${serverFolder}/start-minecraft.sh
+ExecStop=/mnt/persist/minecraft/${serverFolder}/stop-minecraft.sh
+TimeoutStopSec=60
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+startScriptPath="/mnt/persist/minecraft/${serverFolder}/start-minecraft.sh"
+echo "!! Install the start-minecraft.sh wrapper script at $startScriptPath"
+cp minecraft/start-minecraft.sh "$startScriptPath"
+# Make the script executable
+chmod +x "$startScriptPath"
+# Ensure the script is owned by ec2-user
+chown ec2-user:ec2-user "$startScriptPath"
+
+stopScriptPath="/mnt/persist/minecraft/${serverFolder}/stop-minecraft.sh"
+echo "!! Install the stop-minecraft.sh wrapper script at $stopScriptPath"
+cp minecraft/stop-minecraft.sh "$stopScriptPath"
+# Make the script executable
+chmod +x "$stopScriptPath"
+# Ensure the script is owned by ec2-user
+chown ec2-user:ec2-user "$stopScriptPath"
+
+jarPath="/home/ec2-user/minecraft_server_${serverVersion}.jar"
+echo "!! Download Minecraft server JAR to $jarPath"
+sudo -u ec2-user wget -O "$jarPath" "$jarUrl"
+
+symlinkPath="/mnt/persist/minecraft/${serverFolder}/minecraft_server.jar"
+echo "!! Symlink the jar to $symlinkPath"
+sudo -u ec2-user ln -s "$jarPath" "$symlinkPath"
+
+echo "!! reload systemd"
+# Reload systemd to recognize the new service and enable it to start on boot
+systemctl daemon-reload
+systemctl enable minecraft-server.service
+
+# echo "!! start minecraft-server"
+# systemctl start minecraft-server.service
+# ? consider rebooting here..

minecraft/start-minecraft.sh

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+#!/bin/bash
+
+if [ ! -e server.properties ]; then
+  echo "server.properties not found, aborting."
+  exit 1
+fi
+
+# Flag indicating if the installed version of screen is < 4.06
+# that does not support the -Logfile argument.
+# Set legacyScreen=1 for true, and legacyScreen=0 for false.
+legacyScreen=1
+
+logFile="console_$(date +"%Y-%m-%d_%H-%M-%S").log"
+# TODO:
+#   - investigate how closely this mirrors the minecraft logs in /logs
+#   - verify the stop workflow vs instance shutdown - does the minecraft server stop properly?
+
+echo "logfile is $logFile"
+
+if [ "$legacyScreen" -eq 1 ]; then
+  cat << EOF >/tmp/screenrc.$$
+logfile $logFile
+EOF
+  /usr/bin/screen -DmS minecraft -L -c /tmp/screenrc.$$ java -Xmx4092M -Xms4092M -jar minecraft_server.jar
+  rm /tmp/screenrc.$$
+else
+  /usr/bin/screen -DmS minecraft -L -Logfile "$logFile" java -Xmx4092M -Xms4092M -jar minecraft_server.jar
+fi

minecraft/stop-minecraft.sh

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+/usr/bin/screen -S minecraft -p 0 -X stuff "/say systemd is shutting down this service.^M"
+sleep 5
+/usr/bin/screen -S minecraft -p 0 -X stuff "/stop^M"