backup.sh

#!/bin/bash
set -e

show_usage() {
    echo "usage: $0 [-bd]"
    echo
    echo "-b   run backups only"
    echo "-d   dry run (don't create or delete any files)"
}

dry_run_command() {
    if [[ "$dry_run" == "0" ]]; then
        "$@"
    else
        echo "DRY RUN: skipping execution of $1"
    fi
}

backup_only=0
dry_run=0
while getopts ":bd" opt; do
    case "$opt" in
        'b')
            backup_only=1
            ;;
        'd')
            dry_run=1
            ;;
        \?)
            show_usage
            exit
            ;;
    esac
done

umask 0002

max_backups=20
backup="/var/backups/reports"
prod="/var/www/sites/report"
beta="/var/www/sites/beta/Reports"
backup_file="$(date '+%Y%m%d%H%M%S')-reports.tgz"
backup_path="$backup/$backup_file"

echo "Creating backup $backup_file"
dry_run_command tar cfz "$backup_path" --strip-components=3 "$prod"

# Prune latest backup
cd "$backup"
dirlen=$(find . -name "*-reports.tgz" -type f | wc -l)
while (( "$dirlen" > "$max_backups" )); do
    which=$(find . -name "*-reports.tgz" -type f | cut -d '-' -f 1 | sort -n | head -n 1)
    remove="$backup/$which-reports.tgz"
    dry_run_command rm -v "$remove"
    if [[ "$dry_run" == "1" ]]; then
        break
    fi
    dirlen=$(find . -name "*-reports.tgz" -type f | wc -l)
done
if [[ "$backup_only" == "0" ]]; then
    echo "Removing old production"
    dry_run_command rm -r "$prod"/*
    echo "Copying current beta into production"
    dry_run_command cp -r "$beta"/* "$prod"/
else
    echo "Running backup only - skipping copy to production"
fi

echo "Done"