dotfiles/modules/nixos/services/cloudflare.nix
2023-05-31 21:03:08 -04:00

116 lines
2.7 KiB
Nix

# This module is necessary for hosts that are serving through Cloudflare.
{ 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"
];
# Build with Cloudflare plugin for DNS validation
# Otherwise, requires HTTPS to be disabled for issuance
caddy = pkgs.stdenv.mkDerivation rec {
pname = "caddy";
version = "latest";
dontUnpack = true;
nativeBuildInputs = with pkgs; [ git go xcaddy ];
plugins = [
"github.com/caddy-dns/cloudflare@a9d3ae2690a1d232bc9f8fc8b15bd4e0a6960eec"
];
configurePhase = ''
export GOCACHE=$TMPDIR/go-cache
export GOPATH="$TMPDIR/go"
'';
buildPhase = let
pluginArgs =
lib.concatMapStringsSep " " (plugin: "--with ${plugin}") plugins;
in ''
runHook preBuild
${pkgs.xcaddy}/bin/xcaddy build "v${version}" ${pluginArgs}
runHook postBuild
'';
installPhase = ''
runHook preInstall
mkdir -p $out/bin
mv caddy $out/bin
runHook postInstall
'';
};
in {
options.cloudflare.enable = lib.mkEnableOption "Use Cloudflare.";
config = lib.mkIf config.cloudflare.enable {
# Forces Caddy to error if coming from a non-Cloudflare IP
caddy.blocks = [{
match = [{ not = [{ remote_ip.ranges = cloudflareIpRanges; }]; }];
handle = [{
handler = "static_response";
abort = true;
}];
}];
# Tell Caddy to use Cloudflare DNS for ACME challenge validation
services.caddy.package = caddy;
caddy.tlsPolicies = [{
issuers = [{
module = "acme";
challenges = {
dns.provider = {
name = "cloudflare";
api_token = "{env.CF_API_TOKEN}";
};
};
}];
}];
systemd.services.caddy.serviceConfig.EnvironmentFile =
config.secrets.cloudflareApi.dest;
# API key must have access to modify Cloudflare DNS records
secrets.cloudflareApi = {
source = ../../../private/cloudflare-api.age;
dest = "${config.secretsDirectory}/cloudflare-api";
owner = "caddy";
group = "caddy";
};
# Allows Nextcloud to trust Cloudflare IPs
services.nextcloud.config.trustedProxies = cloudflareIpRanges;
};
}