Delete git outdated branches

outdated_branches_cleanup.sh

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

# Reset in case getopts has been used previously in the shell.
OPTIND=1

DRY_RUN=0
KEEP_MONTHS=6  # remove only branches older than keep value
GIT_REF_PREFIX="refs/remotes/origin"
EXCLUDE=('INT' 'QA' 'STAGE' 'master')
EXCLUDE_REGEX="^($(IFS=\|; echo "${EXCLUDE[*]}"))$"

CYAN='\033[0;36m'
RED='\033[0;31m'
NC='\033[0m'


function warn() {
  echo -e "${RED}$@${NC}"
}


function info() {
  echo -e "${CYAN}$@${NC}"
}


function usage {
  cat <<USAGE
Usage: $0 [OPTION] ...
Arguments:
-d, dry-run, just print
-m, delete branches older than X, default is ${KEEP_MONTHS}
USAGE
}


function cleanup_old_branches {
  info "Fetching remote branches..."
  git fetch
  # list just remote branches
  # git branch --remotes | wc -l

  tmpfilename=$(mktemp /tmp/old.branches.XXXX)
  branches=$(git for-each-ref --sort=-committerdate ${GIT_REF_PREFIX} --format='%(refname) | %(committerdate:short) | %(authorname) | %(authoremail)' > ${tmpfilename})

  if [ $DRY_RUN -eq 1 ]; then
    warn "DRY RUN. Just listing outdated branches without any actions!"
  fi
  info "Branches outdated for ${KEEP_MONTHS} months:\n"
  while IFS='' read -r line || [[ -n "$line" ]]; do
    fullbranch=$(echo "${line}" | awk -F "|" '{print $1}')
    branch=${fullbranch#"${GIT_REF_PREFIX}/"}  # remove prefix
    branch="${branch%% }"  # trim trailing whitespace
    if [[ $branch =~ $EXCLUDE_REGEX ]]; then
      warn "Skipping excluded branch [${branch}]..."
      continue
    fi
    commit_date=$(echo "${line}" | awk -F "|" '{print $2}')
    if [[ "${OSTYPE}" == "linux-gnu" ]]; then
      commit_timestamp=$(date -d "${commit_date}" +%s)
      outdated_timestamp=$(date -d "$(date +%Y-%m-%d) -${KEEP_MONTHS} month" +%s)
    elif [[ "${OSTYPE}" == "darwin"* ]]; then
      commit_timestamp=$(date -jf %Y-%m-%d ${commit_date} +%s)
      outdated_timestamp=$(date -jf %Y-%m-%d -v-${KEEP_MONTHS}m $(date +%Y-%m-%d) +%s)
    else
      warn "Unsupported platform. Script will not work properly!"
      exit 1
    fi
    # if last commit in branch was earlier than KEEP_MONTHS from now
    if [ $commit_timestamp -le $outdated_timestamp ]; then
      if [ $DRY_RUN -eq 1 ]; then
        info "${line}"
      else
        warn "REMOVING [${branch}] from remote..."
        info "${line}\n"
        git push origin --delete "${branch}"
      fi
    fi
  done < "${tmpfilename}"
  rm "${tmpfilename}"
}

while getopts "hdm:" opt; do
  case "$opt" in
  h)
    usage
    exit 0
    ;;
  d)
    DRY_RUN=1
    ;;
  m)
    KEEP_MONTHS=$OPTARG
    ;;
  esac
done

shift $((OPTIND-1))

cleanup_old_branches