Git deploy hook

update

#!/usr/bin/env bash
set -e

BRANCH=master
TARGET=/etc/nixos

ref="$1"
oldrev="$2"
newrev="$3"

echo >&2
echo "  System generations" >&2
echo >&2
nix-env --list-generations -p /nix/var/nix/profiles/system | tail -3
echo >&2

if [ "$ref" = "refs/heads/$BRANCH" ]; then
  echo >&2
  echo "  Deploying branch $BRANCH." >&2
  echo >&2
  git --work-tree="$TARGET" diff --stat --summary --find-copies-harder "$oldrev".."$newrev"
  git --work-tree="$TARGET" checkout -f "$newrev"
  git --work-tree="$TARGET" status

  echo >&2
  echo >&2
  echo "  Activating system..." >&2
  echo >&2
  nixos-rebuild switch --show-trace
  echo >&2
  echo >&2
  echo "  System deployed" >&2
  echo >&2
  nix-env --list-generations -p /nix/var/nix/profiles/system | tail -1
  echo >&2
else
  echo "Warning: doing nothing, only the $BRANCH branch will be deployed." >&2
fi