dar_wrapper

#!/usr/bin/env bash
# vim: set shiftwidth=4 softtabstop=4 expandtab foldlevel=0 foldmethod=indent: # vim-modline, don't delete
#############################################################################
# $HGFile: dar_script $
# $HGLocation: /home.crypt/mb/src/tools $

# 1st Author: Massimo
# Created: 2006

# $HGChecked in by: massimo $
# $HGDate: 2015-07-19 17:39 +0200 $
# $HGRevision: 6 $
# $HGBranch:  $
# $HGDesc: updates $
#############################################################################

# Checking Bash version
(( ${BASH_VERSINFO[0]} >= 4 )) || die "This script needs at least bash version 4"

## User Configuration #######################################################
declare -A conf tmp
conf[c_nice]="15"

#conf[c_backup_source]=~
#conf[c_slice]="3800M"
conf[c_backup_onefilesystem]="true"

#conf[c_exclude_dirs]=""

conf[c_empty_dirs]=""

conf[c_exclude_files]="
*.dar
*.swp
"

conf[c_exclude_compress]="
*.AVI
*.GIF
*.GZ
*.JPEG
*.JPG
*.MOV
*.MP*
*.PNG
*.RAR
*.ZIP
*.avi
*.bz2
*.gif
*.gz
*.jar
*.jpeg
*.jpg
*.mov
*.mp*
*.png
*.rar
*.sqfs
*.svgz
*.tar*
*.tgz
*.zip
"
#############################################################################

this_basename="${0##*/}"
this_dirname="${0%/*}"

# Libraries
libs=( output )
for lib in "${libs[@]}"; do
    lib_path="${BASH_PREFIX:-/}usr/local/lib/lib_$lib"
    [[ -e "$lib_path" ]] || { echo "$lib_path not found" 1>&2; exit 1; }
    source "$lib_path"
done

usage() {
    cat <<EOF
Usage: $0 [OPTIONS] <source_root_dir> <target_dir>

Custom backup using dar.
Does differential backups if possible, otherwise full backup.
The filename in <target_dir> will be generated from path <source_root_dir>.

    Options:

    -e, --exclude <file>    File with exclude patterns line-separated
    -f, --full              Force full backup even when differential backup is possible
    -i, --info              Show configuration information
    -d, --debug             Debugging mode
    -h, --help              Show this help

   [-c, --crypt             Encrypt archives (currently not supported)]
EOF
}

print_config() {
    for key in ${!conf[@]}; do
        printf "%-20s = %s\n" "${key#c_}" "${conf[$key]}"
    done | sort
}

while [[ $1 == -* ]]; do
    case "$1" in
        -e|--exclude)   shift
                        if [[ $1 == -* || -z $1 ]]; then
                            die "No exclude pattern file given"
                        fi
                        if [[ ! -r $1 ]]; then
                            die "Cannot read file \"$1\" or no exclude pattern file given"
                        fi
                        while read -r line; do
                            debug "Adding  $line  to exclude_dirs"
                            conf[c_exclude_dirs]+=" $line"
                        done < "$1"
                        shift;;
        -c|--crypt)     opt_crypt=1;    shift;;
        -d|--debug)     opt_debug=1;    shift;;
        -f|--full)      opt_full=1;     shift;;
        -i|--info)      opt_info=1;     shift;;
        -h|--help|-\?)  usage;          exit 0;;
        -*) echo "invalid option: $1" 1>&2; usage; exit 1;;
    esac
done

# Checking for dar binary
dar_bin="$(type -ap dar)" || die "dar binary not found"

# Checking source_root_dir parameter
if [[ -n $1 || -n $opt_info ]]; then
    opt_source="$1"
fi
if [[ -z $opt_source ]]; then
    error "No source root directory given!"
    usage
    exit 1
fi
if [[ ! -d $opt_source ]]; then
    error "Source root directory $opt_source does not exist or is not a directory!"
fi

if [[ $opt_source == "/" ]]; then
    # backup source is /
    conf[c_backup_source]="${opt_source}"
    # Setting generic target basename:
    conf[c_basename]="rootfs"
else
    conf[c_backup_source]="${opt_source%/}"         # Removing trailing /
    # Setting generic target basename:
    conf[c_basename]="${conf[c_backup_source]#/}"   # Removing leading /
    conf[c_basename]="${conf[c_basename]//\//_}"    # Replace '/' by '_'
    conf[c_basename]="${conf[c_basename]##+(_)}"
fi


# Checking target_dir parameter
if [[ -n $2 || -n $opt_info ]]; then
    opt_target="$2"
fi
if [[ -z $opt_target ]]; then
    error "No target directory given!"
    usage
    exit 1
fi
if [[ ! -d $opt_target ]]; then
    error "Target directory $opt_target does not exist or is not a directory!"
elif [[ ! -w $opt_target ]]; then
    error "Target directory $opt_target is not writeable!"
fi
conf[c_backup_destination]="${opt_target%/}"

## System Configuration #####################################################

shopt -s extglob

conf[c_date]="$(date '+%Y%m%d_%H%M%S')"
conf[c_backupfile]="${conf[c_basename]}.${conf[c_date]}"
conf[c_diff_file]="${conf[c_basename]}.diff.${conf[c_date]}"
conf[c_cat_latest_file]="${conf[c_basename]}.last.cat"
conf[c_cat_new_file]="${conf[c_backupfile]}.cat"
conf[c_cat_diff_new_file]="${conf[c_diff_file]}.cat"

conf[c_backup_path]="${conf[c_backup_destination]}/${conf[c_backupfile]}"
conf[c_diff_path]="${conf[c_backup_destination]}/${conf[c_diff_file]}"
conf[c_cat_latest_path]="${conf[c_backup_destination]}/${conf[c_cat_latest_file]}"
conf[c_cat_new_path]="${conf[c_backup_destination]}/${conf[c_cat_new_file]}"
conf[c_cat_diff_new_path]="${conf[c_backup_destination]}/${conf[c_cat_diff_new_file]}"

daropt_cipher="blowfish:"
daropt_others="--beep --compression=bzip2 --verbose"


# Removing spaces:
read -r conf[c_empty_dirs] <<< "${conf[c_empty_dirs]//+([[:space:]]|$'\n')/ }"
read -r conf[c_exclude_compress] <<< "${conf[c_exclude_compress]//+([[:space:]]|$'\n')/ }"
read -r conf[c_exclude_dirs] <<< "${conf[c_exclude_dirs]//+([[:space:]]|$'\n')/ }"
read -r conf[c_exclude_files] <<< "${conf[c_exclude_files]//+([[:space:]]|$'\n')/ }"

# Splitting spaces for -Z, if config variable is not empty:
daropt_string_empty_dirs="${conf[c_empty_dirs]:+-D ${conf[c_empty_dirs]// /' -D '}}"
daropt_string_exclude_compress="${conf[c_exclude_compress]:+-Z ${conf[c_exclude_compress]// /' -Z '}}"
daropt_string_exclude_dirs="${conf[c_exclude_dirs]:+-P ${conf[c_exclude_dirs]// /' -P '}}"
#daropt_string_exclude_files="${conf[c_exclude_files]:+-X '${conf[c_exclude_files]// /' -X '}'}"
 daropt_string_exclude_files="${conf[c_exclude_files]:+-X ${conf[c_exclude_files]// /' -X '}}"

#############################################################################


if [[ -n $opt_info ]]; then
    print_config
    exit 0
fi

renice ${conf[c_nice]} $$ >/dev/null
echo "Backup target: ${conf[c_basename]}"
if [[ -z $opt_full && -r "${conf[c_cat_latest_path]}.1.dar" ]]; then
    echo "Continuing with differential backup..."
    eval_command="$dar_bin \
        --create ${conf[c_diff_path]} \
        --fs-root ${conf[c_backup_source]} \
        --ref ${conf[c_cat_latest_path]} \
        --on-fly-isolate ${conf[c_cat_diff_new_path]} \
        --execute \"ln -sfv ${conf[c_cat_diff_new_file]}.%n.dar ${conf[c_cat_latest_path]}.1.dar\" \
        ${conf[c_backup_onefilesystem]:+--no-mount-points} \
        ${opt_crypt:+ --key $daropt_cipher} \
        ${conf[c_slice]:+--slice ${conf[c_slice]}} \
        $daropt_others $daropt_string_exclude_compress $daropt_string_exclude_dirs $daropt_string_empty_dirs $daropt_string_exclude_files"
        debug "Evaluating $eval_command"
        eval "$eval_command"

        # Encrypting the catalog and deleting the unencrypted:
        if (( $? == 0 )) && [[ -n $opt_crypt ]]; then
            eval_command="$dar_bin \
                --key $daropt_cipher \
                --isolate ${conf[c_cat_latest_path]} \
                --ref ${conf[c_cat_new_path]} &&\
            rm -vf ${conf[c_cat_new_path]}.1.dar"
            debug "Evaluating $eval_command"
            eval "$eval_command"
        fi
else
    echo "Initiating complete backup..."
    eval_command="$dar_bin \
        --create \"${conf[c_backup_path]}\" \
        --fs-root \"${conf[c_backup_source]}\" \
        --on-fly-isolate \"${conf[c_cat_new_path]}\" \
        --execute \"ln -sfv ${conf[c_cat_new_file]}.%n.dar ${conf[c_cat_latest_path]}.1.dar\" \
        ${conf[c_backup_onefilesystem]:+--no-mount-points} \
        ${opt_crypt:+ --key $daropt_cipher} \
        ${conf[c_slice]:+--slice ${conf[c_slice]}} \
        $daropt_others $daropt_string_exclude_compress $daropt_string_exclude_dirs $daropt_string_empty_dirs $daropt_string_exclude_files"
        debug "Evaluating $eval_command"
        eval "$eval_command"
        
        # Encrypting the catalog and deleting the unencrypted:
        if (( $? == 0 )) && [[ -n $opt_crypt ]]; then
            $dar_bin \
                --key $daropt_cipher \
                --isolate ${conf[c_cat_latest_path]} \
                --ref ${conf[c_cat_new_path]} &&\
            rm -vf ${conf[c_cat_new_path]}.1.dar
        fi
fi