valheim-on-aws

Why does this project exist?

This project exists because I wanted a cheaper and more efficient way to host a Valheim server. Using AWS and Terraform this project will create a single Valheim server which is ready to join from the Valheim server browser. It will automatically turn off after ~15 minutes of inactivity (saving you loads of money), and you have the option of using the AWS app to turn it back on whenever you want to play.

Features

• Cheap (~$0.049 USD per hour)
• Updates
• Backups
• Alerts
• Monitoring (Netdata)
• Remote management (AWS app)

Requirements

• MacOS required to run this code (or Linux, but will require some fiddling around)
• AWS account including CLI configured on your machine
• Terraform v0.14+

Usage

1. Create a Terraform backend S3 bucket to store your state files
2. Copy and paste the template folder somewhere on your computer
3. Configure terraform.tf to point at the S3 bucket you just created
4. Create a file called terraform.tfvars as per the input descriptions in inputs.tf E.g.

aws_region       = "ap-southeast-2"    // Choose a region closest to your physical location
domain           = "fakedomain.com"    // (Optional) Used as the monitoring URL
keybase_username = "fakeusername"      // Use Keybase to encrypt AWS user passwords
sns_email        = "mrsmith@gmail.com" // Alert go here e.g. server started, server stopped
world_name       = "super cheap world"
server_name      = "super cheap server"
server_password  = "nohax"
admins = {
  "bob"   = 76561197993928955 // Create an AWS user for remote management and make Valheim admin using SteamID
  "jane"  = 76561197994340319
  "sally" = ""                // Create an AWS user for remote management but don't make Valheim admin
}

5. Run terraform init && terraform apply

Example folder structure

valheim-on-aws           // (this project)
└── your-valheim-server  // (create me)
    ├── inputs.tf        // (copied from ./template)
    ├── main.tf          // (copied from ./template)
    ├── terraform.tf     // (copied from ./template)
    └── terraform.tfvars // (create me), example above)

Monitoring

To view server monitoring metrics visit the monitoring_url output from Terraform after deploying. Note that this URL will change every time the server starts unless you're using your own domain in AWS. In this case I find it's easier to just take note of the public IP address when you turn the server on.

Timings

• It usually takes around 1 minute for Terraform to deploy all the components
• Upon the first deployment the server will take 5-10 minutes to become ready
• Subsequent starts will take 2-3 minutes before appearing on the server browser

Backups

The server logic around backups is as follows:

1. Check if world files exist locally and if so start the server using those
2. If no files exist, try to fetch from backup store and use those
3. If no backup files exist, create a new world and start the server
4. Five minutes after the server has started perform a backup
5. Perform backups every hour after boot

Restores

todo

Infracost

The following breakdown is an estimate based on the region ap-southeast-2 and the monthly cost. A more accurate estimate is the hourly cost since the server is designed to shutdown automatically when not in use.

I.e. 35.74 * 12 / 52 / 7 / 24 = $0.049 USD per hour

 Name                                                            Quantity  Unit                Monthly Cost 
                                                                                                            
 module.main.aws_cloudwatch_metric_alarm.valheim_stopped                                                    
 └─ Standard resolution                                                 1  alarm metrics              $0.10 
                                                                                                            
 module.main.aws_instance.valheim                                                                           
 ├─ Instance usage (Linux/UNIX, on-demand, t3a.medium)                730  hours                     $34.67 
 ├─ CPU credits                                           Cost depends on usage: $0.05 per vCPU-hours       
 └─ root_block_device                                                                                       
    └─ Storage (general purpose SSD, gp2)                               8  GB-months                  $0.96 
                                                                                                            
 module.main.aws_route53_record.valheim[0]                                                                  
 ├─ Standard queries (first 1B)                           Cost depends on usage: $0.40 per 1M queries       
 ├─ Latency based routing queries (first 1B)              Cost depends on usage: $0.60 per 1M queries       
 └─ Geo DNS queries (first 1B)                            Cost depends on usage: $0.70 per 1M queries       
                                                                                                            
 module.main.aws_s3_bucket.valheim                                                                          
 └─ Standard                                                                                                
    ├─ Storage                                            Cost depends on usage: $0.03 per GB-months        
    ├─ PUT, COPY, POST, LIST requests                     Cost depends on usage: $0.0055 per 1k requests    
    ├─ GET, SELECT, and all other requests                Cost depends on usage: $0.00044 per 1k requests   
    ├─ Select data scanned                                Cost depends on usage: $0.00225 per GB-months     
    └─ Select data returned                               Cost depends on usage: $0.0008 per GB-months      
                                                                                                            
 module.main.aws_sns_topic.valheim                                                                          
 └─ Requests                                              Cost depends on usage: $0.50 per 1M requests      
                                                                                                            
 PROJECT TOTAL                                                                                       $35.74 

Source: Infracost v0.8.5 infracost breakdown --path . --show-skipped --no-color

Install dependencies

Currently this installs more than required to run the code, however doesn't include AWS CLI.

make install

Inputs

Name	Description	Type	Default	Required
admins	List of AWS users/Valheim server admins (use their SteamID)	map(any)	{ "default_valheim_user": "" }	no
aws_region	The AWS region to create the Valheim server	string	n/a	yes
domain	Domain name used to create a static monitoring URL	string	""	no
instance_type	AWS EC2 instance type to run the server on (t3a.medium is the minimum size)	string	"t3a.medium"	no
keybase_username	The Keybase username to encrypt AWS user passwords with	string	"marypoppins"	no
purpose	The purpose of the deployment	string	"prod"	no
server_name	The server name	string	n/a	yes
server_password	The server password	string	n/a	yes
sns_email	The email address to send alerts to	string	n/a	yes
unique_id	The ID of the deployment (used for tests)	string	""	no
world_name	The Valheim world name	string	n/a	yes

Outputs

Name	Description
bucket_id	The S3 bucket name
instance_id	The EC2 instance ID
monitoring_url	URL to monitor the Valheim Server
valheim_user_passwords	List of AWS users and their encrypted passwords

Example Terraform State

module.main.data.aws_ami.ubuntu
module.main.data.aws_caller_identity.current
module.main.data.aws_iam_policy.ssm
module.main.data.aws_route53_zone.selected[0]
module.main.aws_cloudwatch_event_rule.valheim_started
module.main.aws_cloudwatch_event_target.valheim_started
module.main.aws_cloudwatch_metric_alarm.valheim_stopped
module.main.aws_iam_group.valheim_users
module.main.aws_iam_group_policy_attachment.valheim_users
module.main.aws_iam_instance_profile.valheim
module.main.aws_iam_policy.valheim
module.main.aws_iam_policy.valheim_cname[0]
module.main.aws_iam_policy.valheim_users
module.main.aws_iam_policy_attachment.ssm
module.main.aws_iam_policy_attachment.valheim
module.main.aws_iam_policy_attachment.valheim_cname[0]
module.main.aws_iam_role.valheim
module.main.aws_iam_user.valheim_user["user1"]
module.main.aws_iam_user.valheim_user["user2"]
module.main.aws_iam_user.valheim_user["user3"]
module.main.aws_iam_user_group_membership.valheim_users["user1"]
module.main.aws_iam_user_group_membership.valheim_users["user2"]
module.main.aws_iam_user_group_membership.valheim_users["user3"]
module.main.aws_iam_user_login_profile.valheim_user["user1"]
module.main.aws_iam_user_login_profile.valheim_user["user2"]
module.main.aws_iam_user_login_profile.valheim_user["user3"]
module.main.aws_instance.valheim
module.main.aws_route53_record.valheim[0]
module.main.aws_s3_bucket.valheim
module.main.aws_s3_bucket_object.admin_list
module.main.aws_s3_bucket_object.backup_valheim
module.main.aws_s3_bucket_object.bootstrap_valheim
module.main.aws_s3_bucket_object.crontab
module.main.aws_s3_bucket_object.install_valheim
module.main.aws_s3_bucket_object.start_valheim
module.main.aws_s3_bucket_object.update_cname[0]
module.main.aws_s3_bucket_object.update_cname_json[0]
module.main.aws_s3_bucket_object.valheim_service
module.main.aws_s3_bucket_policy.valheim
module.main.aws_security_group.ingress
module.main.aws_security_group_rule.egress
module.main.aws_security_group_rule.netdata
module.main.aws_security_group_rule.valheim_ingress
module.main.aws_sns_topic.valheim
module.main.aws_sns_topic_subscription.valheim

todo

• Add docs on performing restores
• Don't include empty keys in admin list
• Fix shellcheck and terraform docs pre commit
• Add tests e.g. cron, scripts exist, ports open, s3 access, etc
• Add support for spot instances