git pre-commit hook for validating YAML files

pre-commit

# .git/hooks/pre-commit
# inspired from https://gist.github.com/maciej-lasyk/f73f8aac271b4df4c7839dd425b4f092


FILES_PATTERN='.*\.yml$'

bin_path=$(type -p /usr/{,local/}{,s}bin/python 2>/dev/null)

if [[ ($bin_path == '') && ($(which python 2> /dev/null) == '') ]];then
	echo '# Not checking Y.ML files, python not found';
	exit 0
fi  

if ! python -c 'import yaml';then 
	echo '# Not checking YML/YAML files';
	echo '# pyyaml package not found, please install with';
	echo '# pip install pyyaml';
	exit 0
fi

for f in $(git diff --cached --diff-filter=d --name-only | grep -E $FILES_PATTERN | grep -v vault)
do
  LINT_CHECK=`python -c 'import yaml,sys;yaml.safe_load(sys.stdin)' < $f 2> /dev/null`
  LINT_STATUS=$?
  if (( $LINT_STATUS != 0 )); then
    SYNTAX_FILES+=("#\t$f")
  fi
done

if (( ${#SYNTAX_FILES[@]} )); then
  echo '# There are files with syntax (YAML) errors in the commit:'
  echo '#'
  ( IFS=$'\n'; echo -e "${SYNTAX_FILES[*]}" )
  echo '#'
  echo "# Please fix these or force the commit with '--no-verify'"
fi