From bbc529287d769d708a900fd0ce8fd4b24e332e0a Mon Sep 17 00:00:00 2001
From: Noah Masur <7386960+nmasur@users.noreply.github.com>
Date: Sat, 30 Mar 2024 15:56:58 +0000
Subject: [PATCH] fix: add second no-proxy dyndns for minecraft and others

---
 flake.nix                                 |  1 +
 modules/common/default.nix                |  4 +++
 modules/nixos/gaming/minecraft-server.nix |  2 ++
 modules/nixos/services/cloudflare.nix     | 40 +++++++++++++++++++++++
 4 files changed, 47 insertions(+)

diff --git a/flake.nix b/flake.nix
index 23d05e4..82288b0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -239,6 +239,7 @@
           influxdb = "influxdb.${baseName}";
           irc = "irc.${baseName}";
           metrics = "metrics.${baseName}";
+          minecraft = "minecraft.${baseName}";
           prometheus = "prom.${baseName}";
           paperless = "paper.${baseName}";
           secrets = "vault.${baseName}";
diff --git a/modules/common/default.nix b/modules/common/default.nix
index 09391ea..7cf9c64 100644
--- a/modules/common/default.nix
+++ b/modules/common/default.nix
@@ -75,6 +75,10 @@
         type = lib.types.str;
         description = "Hostname for metrics server.";
       };
+      minecraft = lib.mkOption {
+        type = lib.types.str;
+        description = "Hostname for Minecraft server.";
+      };
       paperless = lib.mkOption {
         type = lib.types.str;
         description = "Hostname for document server (paperless-ngx).";
diff --git a/modules/nixos/gaming/minecraft-server.nix b/modules/nixos/gaming/minecraft-server.nix
index 9c21b06..869934d 100644
--- a/modules/nixos/gaming/minecraft-server.nix
+++ b/modules/nixos/gaming/minecraft-server.nix
@@ -44,6 +44,8 @@ in {
 
     networking.firewall.allowedTCPPorts = [ publicPort ];
 
+    cloudflare.noProxyDomains = [ config.hostnames.minecraft ];
+
     ## Automatically start and stop Minecraft server based on player connections
 
     # Adapted shamelessly from:
diff --git a/modules/nixos/services/cloudflare.nix b/modules/nixos/services/cloudflare.nix
index 64c4a97..763d34c 100644
--- a/modules/nixos/services/cloudflare.nix
+++ b/modules/nixos/services/cloudflare.nix
@@ -46,6 +46,11 @@ in {
 
   options.cloudflare.enable = lib.mkEnableOption "Use Cloudflare.";
 
+  options.cloudflare.noProxyDomains = lib.mkOption {
+    type = lib.types.listOf lib.types.str;
+    description = "Domains to use for dyndns without CDN proxying.";
+  };
+
   config = lib.mkIf config.cloudflare.enable {
 
     # Forces Caddy to error if coming from a non-Cloudflare IP
@@ -95,6 +100,7 @@ in {
     services.cloudflare-dyndns = {
       enable = true;
       proxied = true;
+      deleteMissing = true;
       apiTokenFile = config.secrets.cloudflare-api.dest;
     };
 
@@ -104,5 +110,39 @@ in {
       requires = [ "cloudflare-api-secret.service" ];
     };
 
+    # Run a second copy of dyn-dns for non-proxied domains
+    # Adapted from: https://github.com/NixOS/nixpkgs/blob/nixos-unstable/nixos/modules/services/networking/cloudflare-dyndns.nix
+    systemd.services.cloudflare-dyndns-noproxy = {
+      description = "CloudFlare Dynamic DNS Client (no proxy)";
+      after = [ "network.target" "cloudflare-api-secret.service" ];
+      requires = [ "cloudflare-api-secret.service" ];
+      wantedBy = [ "multi-user.target" ];
+      startAt = "*:0/5";
+
+      environment = {
+        CLOUDFLARE_DOMAINS = toString config.cloudflare.noProxyDomains;
+      };
+
+      serviceConfig = {
+        Type = "simple";
+        DynamicUser = true;
+        StateDirectory = "cloudflare-dyndns-noproxy";
+        EnvironmentFile = config.services.cloudflare-dyndns.apiTokenFile;
+        ExecStart = let
+          args = [ "--cache-file /var/lib/cloudflare-dyndns-noproxy/ip.cache" ]
+            ++ (if config.services.cloudflare-dyndns.ipv4 then
+              [ "-4" ]
+            else
+              [ "-no-4" ]) ++ (if config.services.cloudflare-dyndns.ipv6 then
+                [ "-6" ]
+              else
+                [ "-no-6" ])
+            ++ lib.optional config.services.cloudflare-dyndns.deleteMissing
+            "--delete-missing";
+
+        in "${pkgs.cloudflare-dyndns}/bin/cloudflare-dyndns ${toString args}";
+      };
+    };
+
   };
 }