use npins

at least that works

README.md

@@ -47,6 +47,27 @@ NOTE: it sometimes takes a while for the services to start up, and in the meanti
     pixelfed-manage user:create --name=test --username=test --email=test@test.com --password=testtest --confirm_email=1
     ```
 
+# Building an installer image
+
+Build an installer image for the desired configuration, e.g. for `peertube`:
+
+```bash
+nix build .#installers.peertube
+```
+
+Upload the image in `./result` to Proxmox when creating a VM.
+Booting the image will format the disk and install NixOS with the desired configuration.
+
+# Deploying an updated machine configuration
+
+> TODO: There is currently no way to specify an actual target machine by name.
+
+Assuming you have SSH configuration with access to the remote `root` user stored for a machine called e.g. `peertube`, deploy the configuration by the same name:
+
+```bash
+nix run .#deploy.peertube
+```
+
 ## debugging notes
 
 - it is sometimes useful to `cat result/bin/run-nixos-vm` to see what's really going on (e.g. which ports are getting forwarded)

default.nix

@@ -0,0 +1,103 @@
+let
+  inputs = import ./npins;
+  system = "x86_64-linux";
+  pkgs = import inputs.nixpkgs { config = { }; overlays = [ ]; system = builtins.currentSystem; };
+  lib = import "${inputs.nixpkgs}/lib" // { inherit nixosSystem; };
+  nixosSystem = args:
+    import "${inputs.nixpkgs}/nixos/lib/eval-config.nix"
+      (
+        {
+          inherit lib;
+          # Allow system to be set modularly in nixpkgs.system.
+          # We set it to null, to remove the "legacy" entrypoint's
+          # non-hermetic default.
+          system = null;
+
+          modules = args.modules;
+        }
+        // builtins.removeAttrs args [ "modules" ]
+      );
+in
+rec {
+  nixosModules = {
+    disko = "${inputs.disko}/module.nix";
+    disk-layout = import ./vm/disk-layout.nix;
+    interactive-vm = import ./vm/interactive-vm.nix;
+    mastodon-vm = import ./vm/mastodon-vm.nix;
+    peertube-vm = import ./vm/peertube-vm.nix;
+    pixelfed-vm = import ./vm/pixelfed-vm.nix;
+  };
+
+  # test with
+  #     nix-build -A nixosConfigurations.<config>.installTest
+  nixosConfigurations = {
+    mastodon = nixosSystem {
+      inherit system;
+      modules = with nixosModules; [
+        disko
+        disk-layout
+        interactive-vm
+        mastodon-vm
+      ];
+    };
+
+    peertube = nixosSystem {
+      inherit system;
+      modules = with nixosModules; [
+        disko
+        disk-layout
+        interactive-vm
+        peertube-vm
+      ];
+    };
+
+    pixelfed = nixosSystem {
+      inherit system;
+      modules = with nixosModules; [
+        disko
+        disk-layout
+        interactive-vm
+        pixelfed-vm
+      ];
+    };
+
+    all = nixosSystem {
+      inherit system;
+      modules = with nixosModules; [
+        interactive-vm
+        disko
+        disk-layout
+        peertube-vm
+        pixelfed-vm
+        mastodon-vm
+      ];
+    };
+  };
+
+  # build with
+  #     nix-build -A installers.<config>
+  installers =
+    let
+      installer = (import ./installer.nix) { inherit lib; outPath = inputs.nixpkgs; };
+    in
+    lib.mapAttrs (_: config: installer config) nixosConfigurations;
+
+  # run with
+  #     $(nix-build -A deploy.<machine> --no-out-link)/bin/deploy
+  deploy =
+    let
+      deployCommand = (pkgs.callPackage ./deploy.nix { });
+    in
+    lib.mapAttrs (name: config: deployCommand name config) nixosConfigurations;
+
+  tests = {
+    mastodon-garage = import ./tests/mastodon-garage.nix { inherit pkgs; };
+    pixelfed-garage = import ./tests/pixelfed-garage.nix { inherit pkgs; };
+  };
+
+  shell = pkgs.mkShell {
+    packages = with pkgs; [
+      nil
+    ];
+  };
+}

deploy.nix

@@ -0,0 +1,13 @@
+{ writeShellApplication }:
+name: config:
+writeShellApplication {
+  name = "deploy";
+  text = ''
+    result="$(nix build ${./.}#nixosConfigurations.${name} --eval-store auto --store ssh-ng://${name})"
+    # shellcheck disable=SC2087
+    ssh ${name} << EOF
+    nix-env -p /nix/var/nix/profiles/system --set "$result"
+    "$result"/bin/switch-to-configuration switch
+    EOF
+  '';
+}

flake.lock

@@ -1,6 +1,40 @@
 {
   "nodes": {
+    "disko": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1727249977,
+        "narHash": "sha256-lAqOCDI4B6hA+t+KHSm/Go8hQF/Ob5sgXaIRtMAnMKw=",
+        "owner": "nix-community",
+        "repo": "disko",
+        "rev": "c1c472f4cd91e4b0703e02810a8c7ed30186b6fa",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "disko",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
+      "locked": {
+        "lastModified": 1725194671,
+        "narHash": "sha256-tLGCFEFTB5TaOKkpfw3iYT9dnk4awTP/q4w+ROpMfuw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b833ff01a0d694b910daca6e2ff4a3f26dee478c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
       "locked": {
         "lastModified": 1723726852,
         "narHash": "sha256-lRzlx4fPRtzA+dgz9Rh4WK5yAW3TsAXx335DQqxY2XY=",
@@ -18,7 +52,8 @@
     },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "disko": "disko",
+        "nixpkgs": "nixpkgs_2"
       }
     }
   },

flake.nix

@@ -3,19 +3,23 @@
 
   inputs = {
     nixpkgs.url = "github:radvendii/nixpkgs/nixos_rebuild_tests";
+    disko.url = "github:nix-community/disko";
   };
 
-  outputs = { self, nixpkgs }:
+  outputs = { self, nixpkgs, disko, ... }:
   let
     system = "x86_64-linux";
     pkgs = nixpkgs.legacyPackages.${system};
   in {
 
     nixosModules = {
+
       ## Fediversity modules
       fediversity = import ./fediversity;
 
       ## VM-specific modules
+      inherit (disko.nixosModules) disko;
+      disk-layout = import ./vm/disk-layout.nix;
       interactive-vm = import ./vm/interactive-vm.nix;
       mastodon-vm = import ./vm/mastodon-vm.nix;
       peertube-vm = import ./vm/peertube-vm.nix;
@@ -25,22 +29,42 @@
     nixosConfigurations = {
       mastodon = nixpkgs.lib.nixosSystem {
         inherit system;
-        modules = with self.nixosModules; [ fediversity interactive-vm mastodon-vm ];
+        modules = with self.nixosModules; [
+          disko
+          disk-layout
+          fediversity
+          interactive-vm
+          mastodon-vm
+        ];
       };
 
       peertube = nixpkgs.lib.nixosSystem {
         inherit system;
-        modules = with self.nixosModules; [ fediversity interactive-vm peertube-vm ];
+        modules = with self.nixosModules; [
+          disko
+          disk-layout
+          fediversity
+          interactive-vm
+          peertube-vm
+        ];
       };
 
       pixelfed = nixpkgs.lib.nixosSystem {
         inherit system;
-        modules = with self.nixosModules; [ fediversity interactive-vm pixelfed-vm ];
+        modules = with self.nixosModules; [
+          disko
+          disk-layout
+          fediversity
+          interactive-vm
+          pixelfed-vm
+        ];
       };
 
       all = nixpkgs.lib.nixosSystem {
         inherit system;
         modules = with self.nixosModules; [
+          disko
+          disk-layout
           fediversity
           interactive-vm
           peertube-vm
@@ -50,13 +74,29 @@
       };
     };
 
+    # build with
+    #     nix build .#installers.<config>
+    installers =
+      let
+        installer = (import ./installer.nix) nixpkgs;
+      in
+      nixpkgs.lib.mapAttrs (_: config: installer config) self.nixosConfigurations;
+
+    # run with
+    #     nix run .#deploy.<machine>
+    deploy =
+      let
+        deployCommand = (pkgs.callPackage ./deploy.nix {});
+      in
+      nixpkgs.lib.mapAttrs (name: config: deployCommand name config) self.nixosConfigurations;
+
     checks.${system} = {
-      mastodon-garage = import ./tests/mastodon-garage.nix { inherit pkgs self; };
-      pixelfed-garage = import ./tests/pixelfed-garage.nix { inherit pkgs self; };
+      mastodon-garage = import ./tests/mastodon-garage.nix { inherit pkgs; };
+      pixelfed-garage = import ./tests/pixelfed-garage.nix { inherit pkgs; };
     };
 
     devShells.${system}.default = pkgs.mkShell {
-      inputs = with pkgs; [
+      packages = with pkgs; [
         nil
       ];
     };

installer.nix

@@ -0,0 +1,29 @@
+/**
+  Convert a NixOS configuration to one for a minimal installer ISO
+
+  WARNING: Running this installer will format the target disk!
+*/
+nixpkgs: machine:
+  let
+    installer = { config, pkgs, ... }:
+      let
+        bootstrap = pkgs.writeShellApplication {
+          name = "bootstrap";
+          runtimeInputs = with pkgs; [ nixos-install-tools ];
+          text = ''
+            ${machine.config.system.build.diskoScript}
+            nixos-install --no-root-password --no-channel-copy --system ${machine.config.system.build.toplevel}
+          '';
+        };
+      in
+      {
+        imports = [
+          "${nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix"
+        ];
+        nixpkgs.hostPlatform = "x86_64-linux";
+        programs.bash.loginShellInit = ''
+          ${nixpkgs.lib.getBin bootstrap}
+        '';
+      };
+  in
+  (nixpkgs.lib.nixosSystem { modules =  [installer];}).config.system.build.isoImage

npins/default.nix

@@ -0,0 +1,80 @@
+# Generated by npins. Do not modify; will be overwritten regularly
+let
+  data = builtins.fromJSON (builtins.readFile ./sources.json);
+  version = data.version;
+
+  mkSource =
+    spec:
+    assert spec ? type;
+    let
+      path =
+        if spec.type == "Git" then
+          mkGitSource spec
+        else if spec.type == "GitRelease" then
+          mkGitSource spec
+        else if spec.type == "PyPi" then
+          mkPyPiSource spec
+        else if spec.type == "Channel" then
+          mkChannelSource spec
+        else
+          builtins.throw "Unknown source type ${spec.type}";
+    in
+    spec // { outPath = path; };
+
+  mkGitSource =
+    {
+      repository,
+      revision,
+      url ? null,
+      hash,
+      branch ? null,
+      ...
+    }:
+    assert repository ? type;
+    # At the moment, either it is a plain git repository (which has an url), or it is a GitHub/GitLab repository
+    # In the latter case, there we will always be an url to the tarball
+    if url != null then
+      (builtins.fetchTarball {
+        inherit url;
+        sha256 = hash; # FIXME: check nix version & use SRI hashes
+      })
+    else
+      assert repository.type == "Git";
+      let
+        urlToName =
+          url: rev:
+          let
+            matched = builtins.match "^.*/([^/]*)(\\.git)?$" repository.url;
+
+            short = builtins.substring 0 7 rev;
+
+            appendShort = if (builtins.match "[a-f0-9]*" rev) != null then "-${short}" else "";
+          in
+          "${if matched == null then "source" else builtins.head matched}${appendShort}";
+        name = urlToName repository.url revision;
+      in
+      builtins.fetchGit {
+        url = repository.url;
+        rev = revision;
+        inherit name;
+        # hash = hash;
+      };
+
+  mkPyPiSource =
+    { url, hash, ... }:
+    builtins.fetchurl {
+      inherit url;
+      sha256 = hash;
+    };
+
+  mkChannelSource =
+    { url, hash, ... }:
+    builtins.fetchTarball {
+      inherit url;
+      sha256 = hash;
+    };
+in
+if version == 3 then
+  builtins.mapAttrs (_: mkSource) data.pins
+else
+  throw "Unsupported format version ${toString version} in sources.json. Try running `npins upgrade`"

npins/sources.json

@@ -0,0 +1,32 @@
+{
+  "pins": {
+    "disko": {
+      "type": "GitRelease",
+      "repository": {
+        "type": "GitHub",
+        "owner": "nix-community",
+        "repo": "disko"
+      },
+      "pre_releases": false,
+      "version_upper_bound": null,
+      "release_prefix": null,
+      "version": "v1.8.0",
+      "revision": "624fd86460e482017ed9c3c3c55a3758c06a4e7f",
+      "url": "https://api.github.com/repos/nix-community/disko/tarball/v1.8.0",
+      "hash": "06ifryv6rw25cz8zda4isczajdgrvcl3aqr145p8njxx5jya2d77"
+    },
+    "nixpkgs": {
+      "type": "Git",
+      "repository": {
+        "type": "GitHub",
+        "owner": "radvendii",
+        "repo": "nixpkgs"
+      },
+      "branch": "nixos_rebuild_tests",
+      "revision": "8648620e5c0d8a63f7319bbdaaa9a7f3bccae0f0",
+      "url": "https://github.com/radvendii/nixpkgs/archive/8648620e5c0d8a63f7319bbdaaa9a7f3bccae0f0.tar.gz",
+      "hash": "18s3731h59rby16hv1vkdjaib91h3myxbr041fndq6j5m7jjkbap"
+    }
+  },
+  "version": 3
+}

shell.nix

@@ -0,0 +1,31 @@
+{ ... }:
+{
+  disko.devices.disk.main = {
+    device = "/dev/sda";
+    type = "disk";
+    content = {
+      type = "gpt";
+      partitions = {
+        ESP = {
+          priority = 1;
+          size = "500M";
+          type = "EF00";
+          content = {
+            type = "filesystem";
+            format = "vfat";
+            mountpoint = "/boot";
+          };
+        };
+        root = {
+          priority = 2;
+          size = "100%";
+          content = {
+            type = "filesystem";
+            format = "ext4";
+            mountpoint = "/";
+          };
+        };
+      };
+    };
+  };
+}

tests/mastodon-garage.nix

@@ -1,4 +1,4 @@
-{ pkgs, self }:
+{ pkgs }:
 let
   lib = pkgs.lib;
   rebuildableTest = import ./rebuildableTest.nix pkgs;
@@ -37,7 +37,7 @@ pkgs.nixosTest {
   nodes = {
     server = { config, ... }: {
       virtualisation.memorySize = lib.mkVMOverride 4096;
-      imports = with self.nixosModules; [ mastodon-vm ];
+      imports = [ ./../vm/mastodon-vm.nix ];
       # TODO: pair down
       environment.systemPackages = with pkgs; [
         python3

tests/pixelfed-garage.nix

@@ -1,4 +1,4 @@
-{ pkgs, self }:
+{ pkgs }:
 let
   lib = pkgs.lib;
   rebuildableTest = import ./rebuildableTest.nix pkgs;
@@ -136,7 +136,7 @@ pkgs.nixosTest {
         memorySize = lib.mkVMOverride 8192;
         cores = 8;
       };
-      imports = with self.nixosModules; [ pixelfed-vm ];
+      imports = [ ../../vm/pixelfed-vm.nix ];
       # TODO: pair down
       environment.systemPackages = with pkgs; [
         python3

vm/disk-layout.nix

@@ -0,0 +1,36 @@
+{ ... }:
+{
+  disko.devices.disk.main = {
+    device = "/dev/sda";
+    type = "disk";
+    content = {
+      type = "gpt";
+      partitions = {
+        MBR = {
+          priority = 0;
+          size = "1M";
+          type = "EF02";
+        };
+        ESP = {
+          priority = 1;
+          size = "500M";
+          type = "EF00";
+          content = {
+            type = "filesystem";
+            format = "vfat";
+            mountpoint = "/boot";
+          };
+        };
+        root = {
+          priority = 2;
+          size = "100%";
+          content = {
+            type = "filesystem";
+            format = "ext4";
+            mountpoint = "/";
+          };
+        };
+      };
+    };
+  };
+}