diff-bitte.sh

#! /usr/env bash

set -o errtrace
set -o pipefail
set -o nounset
set -o errexit

PACKAGE="diff-bitte"

function show_help() {
  echo "$PACKAGE - what happens if this project would use bitte commit XYZ"
  echo " "
  echo "$PACKAGE -c BITTE_COMMIT [-n NODE [-n NODE ] ... ] [-t TFTARGET [-t TFTARGET ] ... ]"
  echo ' '
  echo 'options:'
  echo '-h, --help                show help'
  echo '-c, --commit BITTE_COMMIT diffs against BITTE_COMMIT'
  echo '-n, --node NODE           add nodes to diff'
  echo '-t, --terraform TFTARGET  add terraform targets to diff'
  echo ' '
  echo 'BITTE_COMMIT a commit rev from the bitte repository and the future'
  echo '             right-hand side of the comparision'
  echo ' '
  echo "nix-diff binary path: $(which nix-diff)"
  echo "nix version: $(nix --version)"
}

test $# -eq 0 && (show_help && exit 1)

BITTE_REPO="input-output-hk/bitte"
NODES=()
TFTARGET=()

while test $# -gt 0; do
  case "$1" in
  -h | --help)
    show_help
    exit 0
    ;;
  -c | --commit)
    shift
    if test $# -gt 0; then
      export BITTE_COMMIT=$1
    else
      echo "no BITTE_COMMIT specified"
      exit 1
    fi
    shift
    ;;
  -n | --node)
    shift
    if test $# -gt 0; then
      NODES+=("$1")
    else
      echo "no NODE specified"
      exit 1
    fi
    shift
    ;;
  -t | --terraform)
    shift
    if test $# -gt 0; then
      TFTARGET+=("$1")
    else
      echo "no TFTARGET specified"
      exit 1
    fi
    shift
    ;;
  *)
    show_help
    exit 1
    ;;
  esac
done

swap_bitte=(--override-input bitte "github:$BITTE_REPO/$BITTE_COMMIT" --update-input bitte)

function cmd {
  local cmd
  cmd="$*"
  echo >&2 ">>> $cmd"

  if $cmd 2>/dev/null; then
    echo >&2 "$(
      tput setaf 2
      tput bold
    )OK$(tput sgr 0)"
  else
    echo >&2 "$(
      tput setaf 1
      tput bold
    )COMMAND FAILED$(tput sgr 0)" && exit 1
  fi
}

function diff {
  local attrpath="$1"
  local left
  local right

  echo
  echo "$(tput bold)------------ DIFFING ${attrpath} ...$(tput sgr 0)"

  left=$(cmd nix eval --raw "$PRJ_ROOT#$attrpath.drvPath")
  right=$(cmd nix eval "${swap_bitte[@]}" --raw "$PRJ_ROOT#$attrpath.drvPath")
  echo
  echo "$(
    tput setaf 1
    tput bold
  )- left=$left$(tput sgr 0)"
  echo "$(
    tput setaf 2
    tput bold
  )+ right=$right$(tput sgr 0)"
  echo

  echo "$(tput bold)------------ NIX-DIFF ------------$(tput sgr 0)"
  cmd nix-diff --character-oriented "$left" "$right"
  echo "$(tput bold)------------ DIFF-CLOSURES ------------$(tput sgr 0)"
  cmd nix store diff-closures "$left" "$right"
  echo
  echo
}

for i in "${NODES[@]}"; do
  attrpath="nixosConfigurations.$BITTE_CLUSTER-$i.config.system.build.toplevel"
  diff "$attrpath"
done

for i in "${TFTARGET[@]}"; do
  attrpath="clusters.$BITTE_CLUSTER.tf.$i.config"
  diff "$attrpath"
done