depot/ops/nixos/lib/switch-prebuilt.nix

# SPDX-FileCopyrightText: 2020 Luke Granger-Brown <depot@lukegb.com>
#
# SPDX-License-Identifier: Apache-2.0

{ depot, pkgs, ... }:
pkgs.writeShellScriptBin "switch-prebuilt" ''
  set -ue

  export AWS_ACCESS_KEY_ID="${depot.ops.secrets.nixCache.AWS_ACCESS_KEY_ID}"
  export AWS_SECRET_ACCESS_KEY="${depot.ops.secrets.nixCache.AWS_SECRET_ACCESS_KEY}"
  system="''${1}"

  if [[ "$system" == "latest" ]]; then
    tmpdir="$(mktemp -d)"
    trap '{ rm -rf -- "$tmpdir"; }' EXIT
    
    ${pkgs.curl}/bin/curl -so "$tmpdir/archive.zip" 'https://hg.lukegb.com/api/v4/projects/lukegb%2Fdepot/jobs/artifacts/branch%2Fdefault/download?job=nixCache'
    ${pkgs.unzip}/bin/unzip -d "$tmpdir" -q -o "$tmpdir/archive.zip"
    system="$(${pkgs.jq}/bin/jq -r ".\"$(hostname)\"" "$tmpdir/systems.json")"
  fi

  if [[ ! -e "$system" ]]; then
    # We should be a trusted-user.
    nix copy -v --from 's3://lukegb-nix-cache?endpoint=storage.googleapis.com' --no-check-sigs "$system"
  fi

  diff "$system/etc/hostname" "/etc/hostname"

  # The next phase requires sudo, but it's harmless to run the preceding commands twice.
  if [[ $EUID -ne 0 ]]; then
    exec sudo "$0" "$system"
  fi

  nix-env -p /nix/var/nix/profiles/system --set "$system"
  "$system/bin/switch-to-configuration" switch
''