backup.sh

#!/bin/bash
set -euo pipefail

########################################
# Remote Backup Script
# Usage: ./backup.sh [--dry-run] <config_file>
########################################

NOTIFY_SCRIPT="/usr/local/emhttp/webGui/scripts/notify"
DRY_RUN=false
LOG_FILE=""

########################################
# Argument parsing
########################################
config_file=""
for arg in "$@"; do
    case "$arg" in
        --help)
            echo "Usage: $0 [--dry-run] <config_file>"
            exit 0
            ;;
        --dry-run)
            DRY_RUN=true
            ;;
        -*)
            echo "Unknown option: $arg"
            echo "Usage: $0 [--dry-run] <config_file>"
            exit 1
            ;;
        *)
            config_file="$arg"
            ;;
    esac
done

if [[ -z "$config_file" ]]; then
    echo "Usage: $0 [--dry-run] <config_file>"
    exit 1
fi

########################################
# Logging
########################################
log() {
    local ts
    ts="$(date '+%Y-%m-%d %H:%M:%S')"
    local line="[$ts] $*"
    echo "$line"
    [[ -n "$LOG_FILE" ]] && echo "$line" >> "$LOG_FILE"
}

########################################
# Notifications
########################################
notify_backup_result() {
    local status="$1"
    local message icon

    if [[ "$status" -ne 0 ]]; then
        message="Backup Failed"
        icon="alert"
    else
        message="Backup Completed"
        icon="normal"
    fi

    if [[ -x "$NOTIFY_SCRIPT" ]]; then
        "$NOTIFY_SCRIPT" -e "Remote Server Backup" -s "${config[NAME]:-unknown}" -d "$message" -i "$icon"
    fi
}

########################################
# Verify and load config
########################################
if [[ ! -s "$config_file" ]]; then
    echo "Error: Missing or empty config file ($config_file)"
    exit 1
fi

declare -A config
while IFS='=' read -r key value; do
    [[ -z "$key" || "$key" =~ ^[[:space:]]*# ]] && continue
    key="${key#"${key%%[![:space:]]*}"}"
    key="${key%"${key##*[![:space:]]}"}"
    value="${value#"${value%%[![:space:]]*}"}"
    value="${value%"${value##*[![:space:]]}"}"
    [[ -z "$key" ]] && continue
    config["$key"]="$value"
done < "$config_file"

# Validate required keys
required_keys=(NAME NETWORK DEST REMOTE_IP PORT SSHKEY SOURCE)
for k in "${required_keys[@]}"; do
    if [[ -z "${config[$k]:-}" ]]; then
        echo "Error: Missing required config key: $k"
        exit 1
    fi
done

########################################
# Setup Backup Paths & Logging
########################################
backup_base="${config[DEST]}/${config[NETWORK]}/${config[NAME]}"
daily_dir="$backup_base/Daily"
weekly_dir="$backup_base/Weekly"
monthly_dir="$backup_base/Monthly"

mkdir -p "$backup_base"
LOG_FILE="$backup_base/backup.log"

[[ "$DRY_RUN" == true ]] && log "DRY RUN ENABLED - No actual data will be transferred or modified."

########################################
# Daily Backup
########################################
rsync_base_opts=(-aHAXx --delete)

extra_opts=()
if [[ -n "${config[OPTIONS]:-}" ]]; then
    IFS=' ' read -ra extra_opts <<< "${config[OPTIONS]}"
fi

if [[ "$DRY_RUN" == true ]]; then
    log "DRY RUN - Would make \"$daily_dir\""
    log "DRY RUN - Would sync from remote to \"$daily_dir/\""
    rsync_daily_opts=("${rsync_base_opts[@]}" "${extra_opts[@]}" --dry-run)
else
    mkdir -p "$daily_dir"
    rsync_daily_opts=("${rsync_base_opts[@]}" "${extra_opts[@]}")
fi

rsync "${rsync_daily_opts[@]}" \
    -e "/usr/bin/ssh -o Compression=no -x -p '${config[PORT]}' -i '${config[SSHKEY]}'" \
    "root@${config[REMOTE_IP]}:${config[SOURCE]}" "$daily_dir/" 2>&1 | tee -a "$LOG_FILE" || true
status=${PIPESTATUS[0]}

notify_backup_result "$status"
[[ "$status" -ne 0 ]] && exit 1

########################################
# Weekly Sunday Backup
########################################
if [[ "$(date +%a)" == "Sun" ]]; then
    if [[ "$DRY_RUN" == true ]]; then
        log "DRY RUN - Would make \"$weekly_dir\""
        log "DRY RUN - Would sync: \"$daily_dir/\" -> \"$weekly_dir/\""
        rsync_weekly_opts=("${rsync_base_opts[@]}" --dry-run)
    else
        mkdir -p "$weekly_dir"
        rsync_weekly_opts=("${rsync_base_opts[@]}")
    fi

    rsync "${rsync_weekly_opts[@]}" "$daily_dir/" "$weekly_dir/" 2>&1 | tee -a "$LOG_FILE" || true
    status=${PIPESTATUS[0]}

    notify_backup_result "$status"
    [[ "$status" -ne 0 ]] && exit 1
fi

########################################
# Monthly Backup
########################################
if [[ "$(date +%d)" == "01" ]]; then
    tar_file="$monthly_dir/${config[NAME]}_$(date +%B-%Y).tar.gz"

    if [[ "$DRY_RUN" == true ]]; then
        log "DRY RUN - Would make \"$monthly_dir\""
        log "DRY RUN - Would create archive: \"$tar_file\""
    else
        mkdir -p "$monthly_dir"
        log "Creating monthly archive at \"$tar_file\""
        tar -czf "$tar_file" -C "$(dirname "$daily_dir")" "$(basename "$daily_dir")" 2>&1 | tee -a "$LOG_FILE" || true
        status=${PIPESTATUS[0]}
        if [[ "$status" -ne 0 ]]; then
            log "[!] tar failed"
            notify_backup_result 1
            exit 1
        fi

        log "Generating checksum"
        sha256sum "$tar_file" > "$tar_file.sha256"
        notify_backup_result 0
    fi
fi