Hosting Supabase with a different (api.) subdomain and CloudFlare as DNS provider

[pyciko]

It took me a day and a ton of help from @timothymamo to figure this out, so sharing with everyone else:)

PART 1: Changing the subdomain
You need to modify the subdomain in 5 places, namely

• In the docker-compose.yml file on line 19
• In the supabase.subdomain.conf file on line 5.
• In the .env.tfpl file on line 62 and line 93
• In the network.tf file on line 25

PART 2: Using CloudFlare as DNS provider
First of all, there's a small thing that I still haven't managed to fix. Even though we'll rely 100% on CloudFlare, the build process still asks DO API about the website. You need to register your "domain.com" in Networking -> Domains section and leave it there as it is, without any further actions. This is just to suppress the error.

Create a new file in the terraform/files directory called cloudflare.ini.tftpl with the following:

dns_cloudflare_email = ${TF_CLOUDFLARE_EMAIL}
dns_cloudflare_api_key = ${TF_CLOUDFLARE_API_KEY}

In the locals.tf file remove line 136 and add the following:

cloudflare_ini = templatefile("${path.module}/files/cloudflare.ini.tftpl",
    {
      TF_CLOUDFLARE_EMAIL = "${var.cloudflare_email}",
      TF_CLOUDFLARE_API_KEY = "${var.cloudflare_api_key}"
    }
  )

and change line 169 and 173 (164 and 168 before modification) in the locals.tf file to have the following:

path        = "/root/supabase/cloudflare.ini"
...
content     = base64encode("${local.cloudflare_ini}")

In your docker-compose.yml file change line 24 to the following:
- ./cloudflare.ini:/config/dns-conf/cloudflare.ini

Now go to terraform/providers.tf file and, in required_providers, add

cloudflare = {
      source  = "cloudflare/cloudflare"
      version = "~> 4.0"
    }

then, below, where providers are actually assigned with API keys, add this record:

provider "cloudflare" {
  email = var.cloudflare_email
  api_key = var.cloudflare_api_key
}

Now search for all occurrences of digitalocean_record (1 in network.tf and 5 in sendgrid.tf) and replace it with cloudflare_record, and also swap the domain parameter with "zone_id = var.cloudflare_zone_id" (this is a term used in CF).

Finally, go to variables.tf and add 3 new vars:

variable "cloudflare_email" {
  type        = string
}

variable "cloudflare_api_key" {
  type        = string
}

variable "cloudflare_zone_id" {
  type        = string
}

Zone ID is available in Dashboard, account API KEY is available in My Profile -> API TOKENS.
Now you're good to go, fill the variables in terraform.tfvars and deploy:)

[ndmikkelsen]

Also need to make sure to change line 20 of /packer/supabase/docker-compose.yml from "- DNSPLUGIN=digitalocean" to "- DNSPLUGIN=cloudflare"