add some bootstrap experiement

Author: andir

bootstrap/README.md

@@ -0,0 +1,5 @@
+# Bootstrap a target via cloud-init
+
+```
+hcloud server create --user-data-from-file $(nix-build --no-out-link) --name test --image debian-10 --type cx11
+```

bootstrap/boot.nix

@@ -0,0 +1,18 @@
+let
+  pkgs = import <nixpkgs> {};
+  src = builtins.fetchTarball https://github.com/nix-community/nixos-generators/archive/942232e3000e80b4b4ad34cb3c07923415c27493.tar.gz;
+  generator = import (src + "/nixos-generate.nix");
+
+  diskoSrc = builtins.fetchTarball https://github.com/nix-community/disko/archive/1af856886eca80ce39b61fd97816e4b3be07b236.tar.gz;
+
+  disko = import diskoSrc;
+
+  partitionDisk = disko.create cfg;
+
+in generator {
+  format-config = src + "/formats/kexec-bundle.nix";
+  configuration = ({ config, ... }: {
+    users.users.root.openssh.authorizedKeys.keyFiles = [ /run/root.keys ];
+    services.openssh.enable = true;
+  });
+}

bootstrap/default.nix

@@ -0,0 +1,39 @@
+{ pkgs ? import ../nix/default.nix }:
+let
+  cloud-init = (builtins.toJSON {
+    write_files = [
+      {
+        path = "/run/bootstrap.nix";
+        content = builtins.readFile ./boot.nix;
+      }
+      {
+        path = "/run/root.keys";
+        content = builtins.readFile ../config/profiles/base/andi.pub;
+      }
+    ];
+    bootcmd = [
+      # install curl
+      "apt-get update"
+      "apt-get install -y curl"
+
+      # add user to drive the installer with
+      "echo 'silly    ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers"
+      "useradd silly"
+      # bootstrap nix
+      "curl -o /run/nix.tar.xz https://nixos.org/releases/nix/nix-2.3.2/nix-2.3.2-x86_64-linux.tar.xz"
+      # verify that we didn't download trash
+      "echo bd4cb069d16417ba4aadc5bb005fdb263823990352f9d37c5b763a0bd145394f  /run/nix.tar.xz | sha256sum -c -"
+      # unpack and run install
+      "cd /run && tar -xf ./nix.tar.xz && mv ./nix-* nix"
+      "systemd-run --property=After=local-fs.target --property=User=silly /run/nix/install --daemon"
+
+      # build the installer environment
+      "systemd-run --property=After=local-fs.target nix-build /run/bootstrap.nix --out-link /run/bootstrap"
+      # exec into the installer
+      "systemd-run --property=After=multi-user.target /run/bootstrap"
+    ];
+  });
+in pkgs.writeText "cloud-init" ''
+#cloud-config
+${cloud-init}
+''