shell_sequencer/seqs/backup.sh

#!/bin/bash

# shellcheck disable=SC2001 # See if you can use ${variable//search/replace} instead.
#                             It is more easy with sed to remove multiple trailing /

sq_toolBin=rsync
sq_aptOpt=
sq_config=0

seq_config() {
  if initSeqConfig -t "${seq_configName:?}" "${seq_configTemplate:?}" ; then
    sq_config=1
  else
    error -e "Check output for errors"
    # End if no configuration file exists
    dry || return 1
  fi

  interactive || sq_aptOpt="-y"
  return 0
}

step_1_info() {
  echo "Backup root"
  echoinfo "Essential excludes are provided in the configuration template."
  echoinfo "(${seq_configTemplate})"
}
step_1_options() { echo "[ADDITIONAL_EXCLUDES...]"; }
step_1_alias() { echo "buroot"; }
step_1() {
  local buTarget="/backup"
  if (( ! sq_config )) ; then
    error -e "Cannot backup root without properly configured excludes"
    error -e "     (expected config: ${seq_configFile:?})"
  else
    buTarget="$BACKUP_TARGET"
  fi

  # don't use step number
  shift

  step budir / "$buTarget" "${BACKUP_EXCLUDES[@]}" "$@"
}

step_3_info() {
  # Backup single directory recursively
  local opt=()
  local dir='<SOURCE>'
  local tar='[TARGET]'
  local tarOpt=0
  local exc=()
  shift
  while [[ "${1:-}" =~ ^- ]] ; do
    case "${1}" in 
      --)
        shift && break;;
      -f)
        opt+=("${1:-}" "'${2:-}'")
        shift 2;;
      -t)
        tarOpt=1
        shift;;
      -*)
        opt+=("${1}")
        shift ;;
    esac
  done
  if [ -n "${1:-}" ] ; then
    dir="$1"
    shift
    if (( tarOpt )) ; then
      tar="$BACKUP_TARGET"
    else
      tar="${1:-}"
      shift
    fi
    for arg in "$@" ; do
      exc+=("'$arg'")
    done
    (( ${#exc[@]} )) || exc=("[NO EXCLUDES]")
  fi
  echo     "Backup ${opt[*]} '$dir' '$tar' ${exc[*]}"
  echoinfo " -f : Replace default flags (can be used multiple times)"
  echoinfo "      (default: ${sq_rsyncFlags[*]})"
  echoinfo " -n : No remount to rw"
  echoinfo " -t : Using configuration value as TARGET"
  echoinfo "      <DIRECTORY> [EXCLUDES...]"
  echoinfo "EXCLUDES path notation starts within $dir"
  echoinfo " e.g. to exclude $dir/a:"
  echoinfo " $0 budir $dir $tar /a"
}
sq_rsyncFlags=("-avxHAX" "--delete")
step_3_options() { echo "[OPTION] <DIRECTORY> [TARGET] [EXCLUDES...]"; }
step_3_alias() { echo "budir"; }
step_3() {
  local configTarget=0
  local remount=1
  local buSource=
  local buTarget=
  local buExcludes=
  local buLog=
  local customFlags=()
  # don't use step number
  shift

  for _ in "$@"; do
    case "$1" in
      --)
        shift && break;;
      -t)
        configTarget=1
        shift;;
      -n)
        remount=0
        shift;;
      -f)
        shift
        customFlags+=("${1:-}")
        shift;;
    esac
  done

  (( "${#customFlags[@]}" )) || customFlags=("${sq_rsyncFlags[@]}")
  if [ -z "${1:-}" ] ; then
    error -e "Nothing found to backup $1"
    exit 1
  fi

  buLog="$(basename -- "$1")"
  if [ "$buLog" == "/" ] ; then
    buLog="root"
    buSource="$1"
  else
    # remove trailing slashes
    buSource="$(echo "$1" | sed 's:/*$::')"
  fi
  buLog="backup_${buLog}"
  shift

  if (( configTarget )) && (( sq_config )) ; then
    # Taking target from config
    buTarget="$(echo "$BACKUP_TARGET" | sed 's:/*$::')"
  else
    if [ -z "$1" ] ; then
      error -e "No valid target found"
      exit 1
    fi
    buTarget="$(echo "$1" | sed 's:/*$::')"
    shift
  fi
  if [ ! -d "${buTarget}" ] && [ ! -L "${buTarget}" ]
  then
    error -e "Backup target (${buTarget}) doesn't exist"
    exit 1
  fi

  for exclu in "$@"; do
    buExcludes+=("--exclude='$exclu'")
  done

  info "Source  : $buSource"
  info "Target  : $buTarget"
  info "Excludes: $*"

  #fix doubling trailing slash on verbose output when backing up root
  local tmpSource="$buSource/"
  local tmpTarget=

  tmpTarget="${buTarget}/$(basename -- "${buSource}")"
  if [ "$buSource" == "/" ] ; then
    tmpSource="/"
    tmpTarget="${buTarget}/"
  fi

  if (( remount )) ; then
    # remount target to be writable
    exep "mount -o rw,remount '${buTarget}' >>/dev/null 2>&1"
    endReturn "Remount (${buTarget}) to be writable failed"
  fi

  if [ ! -w "${buTarget}" ] ; then
    error -e "Backup target (${buTarget}) is not writable"
    exit 1
  fi

  checkInstalled
  exep "mv -f '${buTarget}/${buLog}0.log' '/tmp/${buLog}1.log' 2>/dev/null"
  exep "'${sq_toolBin}' ${customFlags[*]} --info=stats2 ${buExcludes[*]} '${tmpSource}' '${tmpTarget}' > '/tmp/${buLog}0.log'"

  # mv is not the right tool moving files to a different file system
  exe cp /tmp/"${buLog}"*.log "${buTarget}"
  exe rm -rf /tmp/"${buLog}"*.log
  exe sync
  if (( remount )) ; then
    exep "mount -o ro,remount '${buTarget}' >>/dev/null 2>&1"
  fi
}

step_100_info() { echo "Install ${sq_toolBin}"; }
step_100_alias() { echo "install"; }
step_100() {
  exe apt update
  exe apt install ${sq_toolBin} ${sq_aptOpt}
}

checkInstalled() {
  if ! command -v ${sq_toolBin} >>/dev/null ; then
    step install
  fi
  sq_toolBin="$(command -v ${sq_toolBin})"
}

# shellcheck disable=SC2034 # Appears unused
readonly sqr_minVersion=16
# shellcheck disable=SC1091 # Don't follow this source
. /usr/local/bin/sequencer.sh