rsync.sh

#!/bin/bash
set -eu -o pipefail
safe_source () { [[ ! -z ${1:-} ]] && source $1; _dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"; _sdir=$(dirname "$(readlink -f "$0")"); }; safe_source
# end of bash boilerplate

safe_source $_sdir/lib/all.sh

# do not exit on errors
set +e

# show help
show_help(){
    cat <<HELP

    $(basename $0) [options] /path/to/source /path/to/destination
    Options:
        --dry-run          : Dry run, don't touch anything actually
        -u                 : Unattended run, don't show yes/no prompt
        --ssh[="settings"] : Switch to SSH mode by using "settings"

    Example:

        rsync.sh --ssh user@myhost:/path/to/src/ /path/to/dest/
        rsync.sh --ssh="-p 1234 -i /path/to/id" user@myhost:/path/to/src/ /path/to/dest/

HELP
    exit
}

die () {
    echo
    echo_red "$1"
    show_help
    exit 255
}


# Parse command line arguments
# ---------------------------
# Initialize parameters
dry_run=false
unattended=false
iredir=false # internal redirect
ssh_mode=false
ssh_settings=
# ---------------------------
args=("$@")
_count=1
while :; do
    key="${1:-}"
    case $key in
        -h|-\?|--help|'')
            show_help    # Display a usage synopsis.
            exit
            ;;
        # --------------------------------------------------------
        --dry-run) shift
            dry_run=true
            ;;
        -u) shift
            unattended=true
            ;;
        --internal-redirect) shift
            iredir=true
            ;;
        --ssh*) shift
            ssh_mode=true
            # use port/id file settings after "=" sign (or null)
            ssh_settings=$(echo $key | sed -e  's/^[^=]*//' | cut -d "=" -f 2)
            ;;
        # --------------------------------------------------------
        -*) # Handle unrecognized options
            echo
            echo "Unknown option: $1"
            show_help
            exit 1
            ;;
        *)  # Generate the positional arguments: $_arg1, $_arg2, ...
            [[ ! -z ${1:-} ]] && declare _arg$((_count++))="$1" && shift
    esac
    [[ -z ${1:-} ]] && break
done; set -- "${args[@]}"
# use $_arg1 in place of $1, $_arg2 in place of $2 and so on, "$@" is intact

src=${_arg1:-}
dest=${_arg2:-}

[[ -z $src ]] && die "Source can not be empty"
[[ -z $dest ]] && die "Destination can not be empty"

[[ $iredir = false ]] && echo_green "Using destination directory: $dest"

if [[ $unattended = false ]]; then
    if ! prompt_yes_no "Should we really continue?"; then
        echo_info "Interrupted by user."
        exit 0
    fi
fi

# All checks are done, run as root
[[ $(whoami) = "root" ]] || { sudo $0 "$@" -u --internal-redirect; exit 0; }

if [[ $ssh_mode = false ]]; then
    for path in $src $dest; do
        if [[ $path =~ ^[a-zA-Z0-9_@.%+-]+\:[0-9]{1,4}.* ]]; then
	    echo_info "It seems that SSH mode is being used with a custom port."
            die "Use --ssh=\"-p ...\" switch to declare the SSH port."
        fi
    done
    for path in $src $dest; do
        if [[ $path =~ ^[a-zA-Z0-9_@.%+-]+\:.* ]]; then
	    echo_info "SSH mode seems to be intended"
            die "Please add the --ssh switch."
        fi
    done
fi

# Cleanup code (should be after "run as root")
sure_exit(){
    echo
    echo_yellow "Interrupted by user."
    exit 5
}
cleanup(){
    exit_code=$?
    if [[ $exit_code -eq 0 ]]; then
        echo_green "Have a nice day."
    else
        echo_red "Something went wrong: Code: $exit_code"
    fi
    exit $exit_code
}
trap sure_exit SIGINT # Runs on Ctrl+C, before EXIT
trap cleanup EXIT



RSYNC="nice -n19 ionice -c3 rsync"
SSH="ssh -o ServerAliveInterval=60 -o ServerAliveCountMax=3 -o ExitOnForwardFailure=yes -o AddressFamily=inet"

start_timer

# build rsync params
_params=
[[ $dry_run = true ]] && _params="$_params --dry-run"
if [[ $ssh_mode = true ]]; then
    ssh_config_path="$(eval echo ~$SUDO_USER)/.ssh/config"
    ssh_config_arg=
    [[ -f ssh_config_path ]] && ssh_config_arg="-F $ssh_config_path"
    ssh_id_path="$(eval echo ~$SUDO_USER)/.ssh/id_rsa"
    _params="$_params --rsh=\"$SSH $ssh_settings $ssh_config_arg\" --rsync-path=\"sudo rsync\""
fi

for i in `seq 1 3`; do
    eval $RSYNC -aHAXvPh $_params --delete --delete-excluded --numeric-ids \
        --filter="\"merge $_sdir/exclude-list.txt\"" "$src" "$dest"
    exit
    exit_code=$?
    if [ $exit_code -eq 11 ]; then
        echo_red "NO Space Left on the device (code $exit_code)"
        # It's useful to retry on "No Space Left on the device" error on BTRFS because
        # user might have deleted some big snapshots recently and btrfs-cleanup might be still
        # working on freeing the available space.
        # TODO: Retry only if it's BTRFS filesystem.
        retry="10m"
        echo_yellow "...will retry in $retry"
        sleep ${retry}
        echo_green "...Retrying..."
        continue
    fi
    break
done

show_timer "sync completed in:"

exit $exit_code