From 48f700b803644dcd18fc6b9911a9366e0ee94faa Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Tue, 17 Dec 2024 14:36:53 -0500
Subject: [PATCH] Add script for managing nix testing vm.

---
 nix/virtual_machine/nix_vm.bash | 100 ++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100755 nix/virtual_machine/nix_vm.bash

diff --git a/nix/virtual_machine/nix_vm.bash b/nix/virtual_machine/nix_vm.bash
new file mode 100755
index 0000000..736a11c
--- /dev/null
+++ b/nix/virtual_machine/nix_vm.bash
@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+#
+# Manage a nix vm for testing.
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+: ${VM_ROOT_ZFS:="zroot/linux/archmain/vm/nix"}
+: ${VM_ROOT_MOUNT:="/vm/nix"}
+: ${VM_DISK_SIZE:="100G"}
+
+# Manual Steps:
+#
+#   Download the nixos livecd from https://channels.nixos.org/nixos-24.11/latest-nixos-gnome-x86_64-linux.iso
+
+############## Setup #########################
+
+function die {
+    local status_code="$1"
+    shift
+    (>&2 echo "${@}")
+    exit "$status_code"
+}
+
+function log {
+    (>&2 echo "${@}")
+}
+
+############## Program #########################
+
+function main {
+    local cmd="$1"
+    shift 1
+    if [ "$cmd" = "init" ]; then
+        vm_init "${@}"
+    elif [ "$cmd" = "install" ]; then
+        vm_install "${@}"
+    elif [ "$cmd" = "run" ]; then
+        vm_run "${@}"
+    elif [ "$cmd" = "iso_ssh" ]; then
+        vm_iso_ssh "${@}"
+    elif [ "$cmd" = "iso_sync" ]; then
+        vm_iso_sync "${@}"
+    else
+        die 1 "Unknown command: $cmd"
+    fi
+}
+
+function vm_init {
+    zfs create -o mountpoint=none -o canmount=off "$VM_ROOT_ZFS"
+    zfs create -u -o "mountpoint=$VM_ROOT_MOUNT" -o canmount=on "$VM_ROOT_ZFS/settings"
+    zfs create -s "-V${VM_DISK_SIZE}" -o volmode=dev -o primarycache=metadata -o secondarycache=none -o volblocksize=64K "${VM_ROOT_ZFS}/disk0"
+
+    zfs snapshot -r "$VM_ROOT_ZFS@empty"
+
+    zfs mount "$VM_ROOT_ZFS/settings"
+
+    # Empty EFI variables
+    cp /usr/share/edk2/x64/OVMF_VARS.4m.fd "${VM_ROOT_MOUNT}/"
+}
+
+function vm_install {
+    VM_CDROM="$1"
+    shift 1
+    vm_run "${@}"
+}
+
+function vm_run {
+    local additional_args=()
+
+    if [ -n "${VM_CDROM:-}" ]; then
+        log "Using CD $VM_CDROM"
+        additional_args+=("-cdrom" "$VM_CDROM")
+    fi
+
+    exec qemu-system-x86_64 \
+         -accel kvm \
+         -cpu host \
+         -smp cores=8 \
+         -m 32768 \
+         -drive file=/usr/share/edk2/x64/OVMF_CODE.4m.fd,if=pflash,format=raw,readonly=on \
+         -drive if=pflash,format=raw,file="$(readlink -f "${VM_ROOT_MOUNT}/OVMF_VARS.4m.fd")" \
+         -drive "if=none,file=/dev/zvol/${VM_ROOT_ZFS}/disk0,format=raw,id=hd0" \
+         -device nvme,serial=deadbeef,drive=hd0 \
+         -nic user,hostfwd=tcp::60022-:22 \
+         -boot order=d \
+         "${additional_args[@]}"
+}
+
+function vm_iso_ssh {
+    exec gpg_auth ssh -p 60022 nixos@127.0.0.1
+}
+
+function vm_iso_sync {
+    gpg_auth rsync -av --delete --progress -e 'ssh -p 60022' "$DIR/../configuration" nixos@127.0.0.1:~/
+    gpg_auth ssh -p 60022 nixos@127.0.0.1 'sudo nix --experimental-features "nix-command flakes" run github:nix-community/disko/latest -- --mode destroy,format,mount ./configuration/hosts/odo/disk-config.nix'
+    gpg_auth ssh -t -p 60022 nixos@127.0.0.1 sudo nixos-install --flake ./configuration#odovm
+}
+
+main "${@}"