Coder Deployment on AWS with Terraform

This Terraform configuration deploys a complete Coder development environment on AWS with a dedicated PostgreSQL database. The setup creates two EC2 instances in your default VPC: one running Coder and another running PostgreSQL.

Architecture

┌─────────────────────────────────────────────────────┐
│                    Default VPC                      │
│                                                     │
│  ┌──────────────────┐      ┌──────────────────┐     │
│  │  Coder Instance  │      │ Postgres Instance│     │
│  │  (t3.medium)     │─────▶│  (t3.medium)     │     │
│  │  Port: 7080      │      │  Port: 5432      │     │
│  │  Public IP       │      │  Public IP       │     │
│  └──────────────────┘      └──────────────────┘     │
│         │                          │                │
│         │ (HTTP/HTTPS)             │ (SSH only)     │
│         ▼                          ▼                │
└─────────────────────────────────────────────────────┘
         │
         ▼
   Internet Access

Security Model

• Coder Instance: Accessible from the internet on ports 80, 443, 7080, and 22 (SSH)
• PostgreSQL Instance: Port 5432 is only accessible from the Coder security group (not from the internet)
• Both instances have public IPs but PostgreSQL is protected by security group rules
• All EBS volumes are encrypted by default

Prerequisites

• Terraform >= 1.0
• AWS CLI configured with credentials
• An AWS account with permissions to create EC2 instances, security groups, and key pairs
• An SSH key pair (or the script will create one for you)

Quick Start

1. Clone the repository

   git clone <repository-url>
   cd <repository-directory>

2. Initialize Terraform

   terraform init

3. Review and customize variables (optional)

   Create a terraform.tfvars file:

   aws_region      = "us-west-2"
   project_name    = "my-coder-deployment"
   coder_version   = "2.18.5"
   instance_type   = "t3.large"

4. Deploy the infrastructure

   terraform apply

5. Access Coder

   After deployment completes, Terraform will output the Coder access URL:

   terraform output coder_access_url

   Open this URL in your browser and complete the initial Coder setup.

Configuration Variables

Variable	Description	Default	Required
aws_region	AWS region to deploy resources	us-east-1	No
instance_type	EC2 instance type	t3.medium	No
key_name	Existing AWS key pair name	"" (creates new)	No
public_key_path	Path to public key file	~/.ssh/id_ed25519.pub	No
postgres_username	PostgreSQL username	coder	No
postgres_password	PostgreSQL password	coder	No
postgres_database	PostgreSQL database name	coder	No
coder_version	Coder version to install	latest	No
project_name	Project name for resource tagging	coder-simple	No
allowed_ssh_cidr	CIDR block allowed to SSH	0.0.0.0/0	No
root_volume_size	Size of root EBS volume (GB)	25	No
root_volume_type	Type of root EBS volume	gp3	No

Security Best Practices

For production deployments, always:

• Set a strong postgres_password
• Restrict allowed_ssh_cidr to your IP or network
• Consider using AWS Secrets Manager for sensitive values
• Use a specific coder_version instead of latest

Example secure configuration:

postgres_password = "your-secure-password-here"
allowed_ssh_cidr  = "203.0.113.0/24"  # Your office/VPN CIDR
coder_version     = "2.29.1"

Outputs

After deployment, the following information is available:

# Get the Coder URL
terraform output coder_access_url

# Get SSH commands
terraform output ssh_command_coder
terraform output ssh_command_postgres

# Get IP addresses
terraform output coder_public_ip
terraform output postgres_private_ip

# Get PostgreSQL connection string (sensitive)
terraform output -raw postgres_connection_string

What Gets Installed

Coder Instance

• Ubuntu 24.04 LTS
• Coder server (specified version)
• Docker and Docker Compose
• PostgreSQL client
• Systemd service for Coder (auto-starts on boot)

PostgreSQL Instance

• Ubuntu 24.04 LTS
• PostgreSQL 14+ (latest from Ubuntu repos)
• Configured to accept connections from Coder instance
• Database and user created automatically

Troubleshooting

Coder not accessible

1. Check if the service is running:

   ssh -i <path_to_key_pair> ubuntu@<coder_public_ip> 'sudo systemctl status coder'

2. View initialization logs:

   ssh -i <path_to_key_pair> ubuntu@<coder_public_ip> 'sudo cat /var/log/user-data.log'

3. Check Coder logs:

   ssh -i <path_to_key_pair> ubuntu@<coder_public_ip> 'sudo journalctl -u coder -n 100'

PostgreSQL connection issues

1. Verify PostgreSQL is running:

   ssh -i <path_to_key_pair> ubuntu@<postgres_public_ip> 'sudo systemctl status postgresql'

2. Test connectivity from Coder instance:

   ssh -i <path_to_key_pair> ubuntu@<coder_public_ip> "pg_isready -h <postgres_private_ip> -p 5432"

3. Check PostgreSQL logs:

   ssh -i <path_to_key_pair> ubuntu@<postgres_public_ip> 'sudo tail -f /var/log/postgresql/postgresql-*-main.log'

Instance not ready

The user-data scripts take 5-10 minutes to complete. You can monitor progress:

ssh ubuntu@<instance_ip> 'tail -f /var/log/user-data.log'

Upgrading Coder

To upgrade Coder to a new version:

1. Update the coder_version variable
2. Run terraform apply
3. SSH into the Coder instance and restart the service:

   sudo systemctl restart coder

Cleanup

To destroy all resources:

terraform destroy

Warning: This will permanently delete all resources including data in PostgreSQL. Make sure to backup any important data first.

Cost Estimation

Using default settings (t3.medium instances in us-east-1):

• 2x t3.medium instances: ~$60/month
• 2x 25GB gp3 volumes: ~$4/month
• Data transfer: Variable

Total estimated cost: ~$65-75/month

Costs will vary based on region, instance type, and usage patterns.

Notes

• This configuration uses the default VPC and subnet
• Both instances are assigned public IPs
• PostgreSQL is configured to listen on all interfaces but is protected by security groups
• All EBS volumes are encrypted
• Docker is installed on the Coder instance for template testing
• The setup is designed for testing/development; additional hardening is recommended for production

Support

For issues with:

• This Terraform configuration: Open an issue in this repository
• Coder itself: Visit Coder's documentation or GitHub
• AWS resources: Consult AWS documentation