Custom octodns setup!

modules/nixos/cloudflared.nix

@@ -8,22 +8,44 @@ in
       description = "Cloudflare tunnel id to use for the `satellite.cloudflared.at` helper";
     };
 
+    domain = lib.mkOption {
+      description = "Root domain to use as a default for configurations.";
+      type = lib.types.str;
+      default = config.satellite.dns.domain;
+    };
+
     at = lib.mkOption {
       description = "List of hosts to set up ingress rules for";
       default = { };
-      type = lib.types.attrsOf (lib.types.submodule ({ name, ... }: {
+      type = lib.types.attrsOf (lib.types.submodule ({ name, config, ... }: {
         options = {
+          subdomain = lib.mkOption {
+            description = ''
+              Subdomain to use for host generation. 
+              Only required if `host` is not set manually.
+            '';
+            type = lib.types.str;
+            default = name;
+          };
+
           port = lib.mkOption {
-            type = lib.types.port;
             description = "Localhost port to point the tunnel at";
+            type = lib.types.port;
           };
 
           host = lib.mkOption {
-            default = name;
-            type = lib.types.str;
             description = "Host to direct traffic from";
+            type = lib.types.str;
+            default = "${config.subdomain}.${cfg.domain}";
+          };
+
+          url = lib.mkOption {
+            description = "External https url used to access this host";
+            type = lib.types.str;
           };
         };
+
+        config.url = "https://${config.host}";
       }));
     };
   };
@@ -34,4 +56,13 @@ in
       value = "http://localhost:${toString port}";
     })
     cfg.at;
+
+  config.satellite.dns.records =
+    let mkDnsRecord = { subdomain, ... }: {
+      type = "CNAME";
+      at = subdomain;
+      zone = cfg.domain;
+      value = "${cfg.tunnel}.cfargotunnel.com.";
+    };
+    in lib.attrsets.mapAttrsToList (_: mkDnsRecord) cfg.at;
 }

modules/nixos/default.nix

@@ -7,4 +7,6 @@
   nginx = import ./nginx.nix;
   pilot = import ./pilot.nix;
   pounce = import ./pounce.nix;
+  dns = import ./dns.nix;
+  dns-assertions = import ./dns-assertions.nix;
 }

modules/nixos/dns-assertions.nix

@@ -0,0 +1,17 @@
+# This must only be loaded on actual Nixos, otherwise `assertions`
+# won't be defined when running `evaluateModules`.
+{ config, ... }:
+let cfg = config.satellite.dns;
+in
+{
+  config.assertions =
+    let assertProperToUsage = config:
+      {
+        assertion = (config.to == null) || (config.type == "CNAME");
+        message = ''
+          The option `satellite.dns.records[*].to` can only be used with `CNAME` records.
+          This was not the case for ${config.type} record at ${config.at}.${config.zone}.
+        '';
+      };
+    in builtins.map assertProperToUsage cfg.records;
+}

modules/nixos/dns.nix

@@ -0,0 +1,59 @@
+{ config, pkgs, lib, ... }:
+let
+  format = pkgs.formats.yaml { };
+  cfg = config.satellite.dns;
+in
+{
+  options.satellite.dns = {
+    domain = lib.mkOption {
+      description = "Default zone to include records in";
+      type = lib.types.str;
+    };
+
+    records = lib.mkOption {
+      description = "List of records to create";
+      default = [ ];
+      type = lib.types.listOf (lib.types.submodule ({ config, ... }: {
+        options = {
+          at = lib.mkOption {
+            description = "Subdomain to use for entry";
+            type = lib.types.nullOr lib.types.str;
+          };
+
+          zone = lib.mkOption {
+            description = "Zone this record is a part of";
+            type = lib.types.str;
+            default = cfg.domain;
+          };
+
+          type = lib.mkOption {
+            type = lib.types.enum [ "A" "AAAA" "TXT" "CNAME" "MX" ];
+            description = "The type of the DNS record";
+          };
+
+          to = lib.mkOption {
+            type = lib.types.nullOr lib.types.str;
+            description = "Shorthand for CNMAE-ing to a subdomain of the given zone";
+            default = null;
+          };
+
+          value = lib.mkOption {
+            type = format.type;
+            description = "The value assigned to the record, in octodns format";
+          };
+
+          ttl = lib.mkOption {
+            type = lib.types.int;
+            description = "The TTL assigned to the record";
+            default = 300;
+          };
+
+          enableCloudflareProxy = lib.mkEnableOption "proxying using cloudflare";
+        };
+
+        config.value = lib.mkIf (config.type == "CNAME" && config.to != null)
+          "${config.to}.${config.zone}.";
+      }));
+    };
+  };
+}

modules/nixos/nginx.nix

@@ -6,24 +6,28 @@ in
     domain = lib.mkOption {
       description = "Root domain to use as a default for configurations.";
       type = lib.types.str;
+      default = config.satellite.dns.domain;
     };
 
     at = lib.mkOption {
       description = "Per-subdomain nginx configuration";
       type = lib.types.attrsOf (lib.types.submodule ({ name, config, ... }: {
-        options.name = lib.mkOption {
-          description = "Attribute name leading to this submodule";
+        options.subdomain = lib.mkOption {
+          description = ''
+            Subdomain to use for host generation. 
+            Only required if `host` is not set manually.
+          '';
           type = lib.types.str;
+          default = name;
         };
 
-        config.name = name;
-
         options.host = lib.mkOption {
           description = "Host to route requests from";
           type = lib.types.str;
-          default = "${name}.${cfg.domain}";
         };
 
+        config.host = "${config.subdomain}.${cfg.domain}";
+
         options.url = lib.mkOption {
           description = "External https url used to access this host";
           type = lib.types.str;
@@ -53,8 +57,8 @@ in
         {
           assertion = (config.port == null) == (config.files != null);
           message = ''
-            Precisely one of the options 'satellite.nginx.at.${config.name}.port'
-            and 'satellite.nginx.at.${config.name}.files' must be specified.
+            Precisely one of the options 'satellite.nginx.at.${config.subdomain}.port'
+            and 'satellite.nginx.at.${config.subdomain}.files' must be specified.
           '';
         };
       in lib.mapAttrsToList (_: assertSingleTarget) cfg.at;
@@ -81,5 +85,14 @@ in
           } // extra;
       };
       in lib.attrsets.mapAttrs' (_: mkNginxConfig) cfg.at;
+
+    satellite.dns.records =
+      let mkDnsRecord = { subdomain, ... }: {
+        type = "CNAME";
+        zone = cfg.domain;
+        at = subdomain;
+        to = config.networking.hostName;
+      };
+      in lib.attrsets.mapAttrsToList (_: mkDnsRecord) cfg.at;
   };
 }