McTerraform - A terraform'ed Minecraft server (with auto-destroy on inactivity)

Deploy Minecraft server using terraform to AWS.

Uses lambda functions to auto-destroy a Minecraft server instance after inactivity. S3 is used for Minecraft world backups and for storing terraform state.

Future functionality:

• add Discord bot for both starting and stopping the Minecraft instance

Prerequisites

• An AWS account with user credentials for programmatic access - see https://docs.aws.amazon.com/IAM/latest/UserGuide/id_users_create.html#id_users_create_console
• Download and install terraform from https://www.terraform.io/downloads.html
• For running the scripted setup of the Terraform resoources, install the AWS CLI at https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-install.html
• For local development (optional): python 3.7, and pip installed

Configuration

Local Development

• Install virtualenv: sudo pip install virtualenv
• Change into source directory cd src
• Activate venv: . venv/bin/activate
• Install dependencies: pip install -r requirements.txt

AWS

• Create IAM credentials for programmatic access and add locally as named AWS credential
  • Update config/account.tfvars, iac/mc-static/config.tf, and iac/mc-server/config.tf with your credentials and your region and an unique name for your S3 bucket for Terraform state

Manual setup

• Create S3 bucket and DynamoDB table for terraform state via the AWS console
  • Create the DynamoDB table with LockID as key attribute
• Create EC2 key via the AWS console

Scripted Setup

• Run ./init_tf_req.shin the root of the locally cloned repo

Deployment Options

• Copy latest Minecraft server download URL into src/mc-server.sh.

Deployment Initialisation

• Init terraform: terraform init in iac/mc-staticand iac/mc-server

Deployment

Static Resources (once)

• Change to static infrastructure setup: cd iac/mc-static
• Execute: terraform apply -var-file=../../config/account.tfvars
• Creates: S3 bucket for Minecraft World backup, Public IP, SNS topic plus attached Lambda for auto-destroy

Server Resources

• Change to server infrastructure setup: cd iac/mc-server
• Execute: terraform apply -var-file=../../config/account.tfvars
• Creates: Minecraft Server with attached Public IP

How it all works

Beyond the allocation of AWs resources, the terraform script triggers modification of the ec2 instance. It installs the Minecraft server, downloads the S3 backed-up minecraft world to the local instance, and add's a crontab script for detecting idle state. Once idle state has been detected, it triggers a backup of the current minecraft world to S3, and triggering the destruction of the ec2 instance by sending an empty message on the SNS destroy topic.

Attached to the SNS Topic is a lambda function, which downloads and installs terraform locally within the lambda context and executes a 'terraform destroy' on the server resources.

Misc

Debugging

• Logging into ec2 instance using the EC2 key: ssh -i ~/.ssh/minecraft.pem ec2-user@<eip>
• Listing available screen sessions: screen -ls
• Re-attaching to minecraft screen session: screen -r minecraft

Updating Minecraft

• Add new Minecraft version download URL in src/mc-setup.sh
• Remove eula.txt file in root of minecraft backup S3 bucket
• Re-apply terraform with terraform apply -var-file=../config/account.tfvars

Additional links

• https://www.codingforentrepreneurs.com/blog/install-django-on-mac-or-linux - installing python on MacOS
• https://jeremievallee.com/2017/03/26/aws-lambda-terraform.html - deploying AWs Lambda with terraform