Production-Grade (ish) server orchestration with Kamal

This is the architecture of our small cluster:

Architecture

It creates two servers: web where our application lives and accessories where our dependencies like databases and caches live. web exposes ports 80, 22 and 443, while accessories is not accessible from the outside. Root access is disabled on both machines and only the kamal user can SSH into them.

Important

If you are copying this workflow, you should change the SSH keys in cloudinit/base.yaml to your own. It is defined on ssh_import_id and imports the SSH keys from your GitHub account.

The machines

Both machines are CPX11: 2 AMD vCPUs, 2 GB of RAM and 40 GB of SSD storage, running Ubuntu 22.04. See variables.tf for more details and how to change them.

Price

This setup will cost you around 10 EUR/month.

How to use it

1. Clone
2. Create a file terraform.tfvars with your credentials, it will look like this:

hetzner_api_key = "your-api-key"

3. Run terraform init
4. Run terraform plan (optional)
5. Run terraform apply