This small setup can be used to provision Flatcar nodes on DigitalOcean.

Create a terraform.tfvars file that lists your preferences. Like this one:

cluster_name           = "mycluster"
machines               = ["mynode"]
datacenter             = "nyc3"
ssh_keys               = ["ssh-rsa AA... [email protected]"]
flatcar_stable_version = "x.y.z"

You can resolve the latest Flatcar Stable version with this shell command:

curl -sSfL https://stable.release.flatcar-linux.net/amd64-usr/current/version.txt | grep -m 1 FLATCAR_VERSION_ID= | cut -d = -f 2

The machine name listed in the machines variable is used to retrieve the corresponding Container Linux Config. For each machine in the list, you should have a machine-NAME.yaml.tmpl file with a corresponding name. An example file machine-mynode.yaml.tmpl for mynode is already provided.

Now run Terraform (version 13) as follows:

export DIGITALOCEAN_TOKEN=...
terraform init
terraform apply

When terraform is done running, it will print the IP addresses of the machines created. Log in via ssh core@IPADDRESS (maybe add -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null).

When you make a change to machine-mynode.yaml.tmpl and run terraform apply again, the instance will be replaced. Consider using create_before_destroy in your final setup.