From 709441590bfe576ebba8843e2842b803bc0ff8dc Mon Sep 17 00:00:00 2001
From: Markus Schmidl <markus.schmidl@mailbox.tu-dresden.de>
Date: Wed, 22 Nov 2023 23:53:42 +0100
Subject: [PATCH] add test-vm

---
 .gitignore           |  1 +
 flake.nix            | 50 ++++++++++++++++++++++++++++++++++++++--
 tests/vm/default.nix | 55 ++++++++++++++++++++++++++++++++++++++++++++
 tests/vm/lizard.nix  | 29 +++++++++++++++++++++++
 4 files changed, 133 insertions(+), 2 deletions(-)
 create mode 100644 tests/vm/default.nix
 create mode 100644 tests/vm/lizard.nix

diff --git a/.gitignore b/.gitignore
index 1fbc882..a82d537 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /target
 result
 .direnv
+nixos.qcow2
diff --git a/flake.nix b/flake.nix
index f0cfa04..355914b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -33,11 +33,33 @@
               rustc = toolchain;
             }).buildPackage;
           };
+
+          test-vm-pkg = self.nixosConfigurations.lizard-mctest.config.system.build.vm;
         in
         rec {
           checks = packages;
           packages = {
             lizard = package;
+            test-vm = test-vm-pkg;
+            test-vm-wrapper = pkgs.writeScript "trekkie-test-vm-wrapper"
+            ''
+              set -e
+
+              echo Trekkie-McTest: enterprise-grade, free-range, grass fed testing vm
+              echo
+              echo "ALL RELEVANT SERVICES WILL BE EXPOSED TO THE HOST:"
+              echo -e "Service\t\tPort"
+              echo -e "SSH:\t\t2222\troot:lol"
+              echo -e "lizard:\t8060"
+              echo -e "redis:\t\t8061"
+              echo
+
+              set -x
+              export QEMU_NET_OPTS="hostfwd=tcp::2222-:22,hostfwd=tcp::8060-:8060,hostfwd=tcp::8061-:6379"
+
+              echo "running the vm now..."
+              ${self.packages.${system}.test-vm}/bin/run-nixos-vm
+            '';
             default = package;
             docs = (pkgs.nixosOptionsDoc {
               options = (nixpkgs.lib.nixosSystem {
@@ -47,6 +69,14 @@
             }).optionsCommonMark;
           };
 
+          # to get yourself a virtualized testing playground:
+          # nix run .\#mctest
+          apps = {
+            mctest = {
+              type = "app";
+              program = "${self.packages.${system}.test-vm-wrapper}";
+            };
+          };
           devShells.default = pkgs.mkShell {
             nativeBuildInputs = (with packages.lizard; nativeBuildInputs ++ buildInputs);
           };
@@ -57,12 +87,28 @@
           };
         }) // {
       nixosModules = rec {
-        default = funnel;
-        funnel = import ./nixos-module;
+        default = lizard;
+        lizard = import ./nixos-module;
       };
       overlays.default = final: prev: {
         inherit (self.packages.${prev.system})
           lizard;
       };
+
+      # qemu vm for testing
+      nixosConfigurations.lizard-mctest = nixpkgs.lib.nixosSystem {
+        system = "x86_64-linux";
+        specialArgs = { inherit inputs; };
+        modules = [
+          self.nixosModules.default
+          ./tests/vm
+
+          {
+            nixpkgs.overlays = [
+              self.overlays.default
+            ];
+          }
+        ];
+      };
     };
 }
diff --git a/tests/vm/default.nix b/tests/vm/default.nix
new file mode 100644
index 0000000..4e46422
--- /dev/null
+++ b/tests/vm/default.nix
@@ -0,0 +1,55 @@
+# add-hoc config for a test VM. 
+{ inputs, modulesPath, ... }:
+{
+  imports = [
+    "${modulesPath}/virtualisation/qemu-vm.nix"
+    ./lizard.nix
+  ];
+
+  fileSystems = {
+    "/" = {
+      device = "/dev/disk/by-label/nixos";
+      fsType = "ext4";
+    };
+  };
+
+  boot = {
+    kernelParams = [ "console=ttyS0" "boot.shell_on_fail" ];
+    loader.timeout = 5;
+  };
+
+  virtualisation = {
+    diskSize = 512;
+    memorySize = 512;
+    graphics = false;
+  };
+
+  services.getty = {
+    autologinUser = "root";
+  };
+  users.motd = ''
+  Trekkie-McTest: enterprise-grade, free-range, grass-fed testing vm
+  Now with 100% less graphics!
+
+  Services exposed to the host:
+  lizard: 8060
+  SSH: 2222
+  redis: 8061
+
+  root password is "lol"
+
+  have fun!
+  '';
+
+
+  networking.firewall.enable = false;
+
+  users.mutableUsers = false;
+  users.users.root.password = "lol";
+  services.openssh = {
+    enable = true;
+    permitRootLogin = "yes";
+  };
+
+  system.stateVersion = "22.11";
+}
diff --git a/tests/vm/lizard.nix b/tests/vm/lizard.nix
new file mode 100644
index 0000000..ad47ab4
--- /dev/null
+++ b/tests/vm/lizard.nix
@@ -0,0 +1,29 @@
+{ config, inputs, ... }:
+{
+  TLMS.lizard = {
+    # Unlike the production, we do not reverse-proxy the lizard, we just expose
+    # port directly to the host vm.
+    enable = true;
+    http = {
+      host = "0.0.0.0";
+      port = 8060;
+    };
+    redis = {
+      port = 6379;
+      host = "localhost";
+    };
+    logLevel = "info";
+  };
+  systemd.services."lizard" = {
+    after = [ "redis-lizard.service" ];
+    wants = [ "redis-lizard.service" ];
+  };
+
+  services = {
+    redis.servers."lizard" = {
+      enable = true;
+      bind = config.TLMS.lizard.redis.host;
+      port = config.TLMS.lizard.redis.port;
+    };
+  };
+}