initial(ish) commit

nixos-modules/networking/tailscale.nix

@@ -0,0 +1,45 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.ragon.services.tailscale;
+in
+{
+  options.ragon.services.tailscale.enable = lib.mkEnableOption "Enables tailscale";
+  config = lib.mkIf cfg.enable {
+    # enable the tailscale service
+    services.tailscale.enable = true;
+    ragon.agenix.secrets.tailscaleKey = {};
+    networking.firewall = {
+      # always allow traffic from your Tailscale network
+      trustedInterfaces = [ "tailscale0" ];
+
+      # allow the Tailscale UDP port through the firewall
+      allowedUDPPorts = [ config.services.tailscale.port ];
+    };
+    systemd.services.tailscale-autoconnect = {
+      description = "Automatic connection to Tailscale";
+
+      # make sure tailscale is running before trying to connect to tailscale
+      after = [ "network-pre.target" "tailscale.service" ];
+      wants = [ "network-pre.target" "tailscale.service" ];
+      wantedBy = [ "multi-user.target" ];
+
+      # set this service as a oneshot job
+      serviceConfig.Type = "oneshot";
+
+      # have the job run this shell script
+      script = with pkgs; ''
+        # wait for tailscaled to settle
+        sleep 2
+
+        # check if we are already authenticated to tailscale
+        status="$(${tailscale}/bin/tailscale status -json | ${jq}/bin/jq -r .BackendState)"
+        if [ $status = "Running" ]; then # if so, then do nothing
+          exit 0
+        fi
+        key=$(<${config.age.secrets.tailscaleKey.path})
+        # otherwise authenticate with tailscale
+        ${tailscale}/bin/tailscale up -authkey $key
+      '';
+    };
+  };
+}