Initial commitHEADmaster

1 files changed, 72 insertions, 0 deletions

diff --git a/kexec.nix b/kexec.nix
new file mode 100644
index 0000000..3556f28
--- /dev/null
+++ b/kexec.nix
@@ -0,0 +1,72 @@
+{ pkgs, config, ... }:
+
+{
+  system.build = rec {
+    image = pkgs.runCommand "image" { buildInputs = [ pkgs.nukeReferences ]; } ''
+      mkdir $out
+      cp ${config.system.build.kernel}/bzImage $out/kernel
+      cp ${config.system.build.netbootRamdisk}/initrd $out/initrd
+      echo "init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}" > $out/cmdline
+      nuke-refs $out/kernel
+    '';
+
+    kexec_script = pkgs.writeTextFile {
+      executable = true;
+      name = "kexec-nixos";
+      text = ''
+        #!${pkgs.stdenv.shell}
+        export PATH=${pkgs.kexectools}/bin:${pkgs.cpio}/bin:$PATH
+        set -x
+        cd $(mktemp -d)
+        pwd
+        mkdir initrd
+        pushd initrd
+        cat /ssh_pubkey >> authorized_keys
+        find -type f | cpio -o -H newc | gzip -9 > ../extra.gz
+        popd
+        cat ${image}/initrd extra.gz > final.gz
+
+        kexec -l ${image}/kernel --initrd=final.gz --append="init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
+        sync
+        echo "executing kernel, filesystems will be improperly umounted"
+        kexec -e
+        '';
+    };
+
+    kexec_tarball = pkgs.callPackage <nixpkgs/nixos/lib/make-system-tarball.nix> {
+      storeContents = [
+        { object = config.system.build.kexec_script; symlink = "/kexec_nixos"; }
+      ];
+      contents = [];
+    };
+
+    kexec_tarball_self_extract_script = pkgs.writeTextFile {
+      executable = true;
+      name = "kexec-nixos";
+      text = ''
+        #!/bin/sh
+        ARCHIVE=`awk '/^__ARCHIVE_BELOW__/ { print NR + 1; exit 0; }' $0`
+
+        tail -n+$ARCHIVE $0 | tar xJ -C /
+        /kexec_nixos
+
+        exit 0
+
+        __ARCHIVE_BELOW__
+      '';
+    };
+
+    kexec_bundle = pkgs.runCommand "kexec_bundle" {} ''
+      cat \
+        ${kexec_tarball_self_extract_script} \
+        ${kexec_tarball}/tarball/nixos-system-${kexec_tarball.system}.tar.xz \
+        > $out
+      chmod +x $out
+    '';
+  };
+
+  boot.initrd.postMountCommands = ''
+    mkdir -p /mnt-root/root/.ssh/
+    cp /authorized_keys /mnt-root/root/.ssh/
+  '';
+}