dotfiles/modules/nixos/services/cloudflare.nix
2024-03-24 18:31:28 -04:00

113 lines
3.2 KiB
Nix

# This module is necessary for hosts that are serving through Cloudflare.
# Cloudflare is a CDN service that is used to serve the domain names and
# caching for my websites and services. Since Cloudflare acts as our proxy, we
# must allow access over the Internet from Cloudflare's IP ranges.
# We also want to validate our HTTPS certificates from Caddy. We'll use Caddy's
# DNS validation plugin to connect to Cloudflare and automatically create
# validation DNS records for our generated certificates.
{ config, pkgs, lib, ... }:
let
cloudflareIpRanges = [
# Cloudflare IPv4: https://www.cloudflare.com/ips-v4
"173.245.48.0/20"
"103.21.244.0/22"
"103.22.200.0/22"
"103.31.4.0/22"
"141.101.64.0/18"
"108.162.192.0/18"
"190.93.240.0/20"
"188.114.96.0/20"
"197.234.240.0/22"
"198.41.128.0/17"
"162.158.0.0/15"
"104.16.0.0/13"
"104.24.0.0/14"
"172.64.0.0/13"
"131.0.72.0/22"
# Cloudflare IPv6: https://www.cloudflare.com/ips-v6
"2400:cb00::/32"
"2606:4700::/32"
"2803:f800::/32"
"2405:b500::/32"
"2405:8100::/32"
"2a06:98c0::/29"
"2c0f:f248::/32"
];
in {
options.cloudflare.enable = lib.mkEnableOption "Use Cloudflare.";
config = lib.mkIf config.cloudflare.enable {
# Forces Caddy to error if coming from a non-Cloudflare IP
caddy.cidrAllowlist = cloudflareIpRanges;
# Tell Caddy to use Cloudflare DNS for ACME challenge validation
services.caddy.package = pkgs.caddy-cloudflare; # Patched overlay
caddy.tlsPolicies = [{
issuers = [{
module = "acme";
challenges = {
dns = {
provider = {
name = "cloudflare";
api_token = "{env.CLOUDFLARE_API_TOKEN}";
};
resolvers = [ "1.1.1.1" ];
};
};
}];
}];
# Allow Caddy to read Cloudflare API key for DNS validation
systemd.services.caddy.serviceConfig.EnvironmentFile =
config.secrets.cloudflare-api.dest;
# API key must have access to modify Cloudflare DNS records
secrets.cloudflare-api = {
source = ../../../private/cloudflare-api.age;
dest = "${config.secretsDirectory}/cloudflare-api";
owner = "caddy";
group = "caddy";
};
systemd.services.cloudflare-api-secret.serviceConfig.ExecStartPost = ''
/run/current-system/sw/bin/systemctl restart caddy.service
/run/current-system/sw/bin/systemctl restart cloudflare-dyndns.service
'';
# Wait for secret to exist
systemd.services.caddy = {
after = [ "cloudflare-api-secret.service" ];
requires = [ "cloudflare-api-secret.service" ];
};
# Allows Nextcloud to trust Cloudflare IPs
services.nextcloud.settings.trusted_proxies = cloudflareIpRanges;
# Allows Transmission to trust Cloudflare IPs
services.transmission.settings.rpc-whitelist =
builtins.concatStringsSep "," ([ "127.0.0.1" ] ++ cloudflareIpRanges);
services.cloudflare-dyndns = {
enable = true;
proxied = true;
apiTokenFile = config.secrets.cloudflare-api.dest;
};
# Wait for secret to exist
systemd.services.cloudflare-dyndns = {
after = [ "cloudflare-api-secret.service" ];
requires = [ "cloudflare-api-secret.service" ];
};
};
}