Backup Automation

#!/usr/bin/env bash
set -euo pipefail

readonly BACKUP_DIR="/backups/postgres"
readonly DB_NAME="myapp"
readonly RETENTION_DAYS=7

mkdir -p "$BACKUP_DIR"

# Dump with timestamp
TIMESTAMP=$(date '+%Y%m%d-%H%M%S')
BACKUP_FILE="$BACKUP_DIR/$DB_NAME-$TIMESTAMP.sql.gz"

pg_dump "$DB_NAME" | gzip > "$BACKUP_FILE"

echo "Backup created: $BACKUP_FILE"
echo "Size: $(du -h "$BACKUP_FILE" | cut -f1)"

# Verify backup is not empty
if [[ ! -s "$BACKUP_FILE" ]]; then
    echo "ERROR: Backup file is empty"
    rm -f "$BACKUP_FILE"
    exit 1
fi

# Cleanup old backups
find "$BACKUP_DIR" -name "*.sql.gz" -mtime +$RETENTION_DAYS -delete
echo "Cleaned up backups older than $RETENTION_DAYS days"

#!/usr/bin/env bash
set -euo pipefail

readonly BACKUP_DIR="/backups/mysql"
readonly DB_NAME="myapp"
readonly TIMESTAMP=$(date '+%Y%m%d-%H%M%S')

mkdir -p "$BACKUP_DIR"

mysqldump \
    --user="$DB_USER" \
    --password="$DB_PASS" \
    --single-transaction \
    --routines \
    --triggers \
    "$DB_NAME" | gzip > "$BACKUP_DIR/$DB_NAME-$TIMESTAMP.sql.gz"

echo "MySQL backup complete"

#!/usr/bin/env bash
set -euo pipefail

readonly SOURCE="/var/www/app"
readonly DEST="/backups/files"
readonly TIMESTAMP=$(date '+%Y%m%d-%H%M%S')

# Incremental backup with rsync
rsync -av --delete \
    --link-dest="$DEST/latest" \
    "$SOURCE/" "$DEST/$TIMESTAMP/"

# Update latest symlink
ln -snf "$DEST/$TIMESTAMP" "$DEST/latest"

echo "File backup complete: $DEST/$TIMESTAMP"

#!/usr/bin/env bash

# gzip — fast, good compression
tar -czf backup.tar.gz /data

# bzip2 — slower, better compression
tar -cjf backup.tar.bz2 /data

# xz — slowest, best compression
tar -cJf backup.tar.xz /data

# pigz — parallel gzip (multi-core)
tar -I pigz -cf backup.tar.gz /data

# zstd — modern, fast compression (recommended)
tar --zstd -cf backup.tar.zst /data

# Encrypted backup
tar -czf - /data | gpg -c -o backup.tar.gz.gpg

# Encrypted with symmetric key
tar -czf - /data | \
    openssl enc -aes-256-cbc -salt -out backup.tar.gz.enc

#!/usr/bin/env bash
set -euo pipefail

BACKUP_DIR="/backups"
KEEP_DAILY=7
KEEP_WEEKLY=4
KEEP_MONTHLY=12

rotate_backups() {
    echo "Starting backup rotation..."

    # Delete daily backups older than 7 days
    find "$BACKUP_DIR/daily" -name "*.tar.gz" -mtime +$KEEP_DAILY -delete

    # Delete weekly backups older than 4 weeks
    find "$BACKUP_DIR/weekly" -name "*.tar.gz" -mtime +$((KEEP_WEEKLY * 7)) -delete

    # Delete monthly backups older than 12 months
    find "$BACKUP_DIR/monthly" -name "*.tar.gz" -mtime +$((KEEP_MONTHLY * 30)) -delete

    echo "Rotation complete"
}

# Daily backup
daily_backup() {
    mkdir -p "$BACKUP_DIR/daily"
    local file="$BACKUP_DIR/daily/backup-$(date +%Y%m%d).tar.gz"
    tar -czf "$file" /data
    echo "Daily backup: $file"
}

# Weekly backup (Sundays)
if [[ $(date +%u) -eq 7 ]]; then
    mkdir -p "$BACKUP_DIR/weekly"
    tar -czf "$BACKUP_DIR/weekly/backup-$(date +%Y%m%d).tar.gz" /data
fi

# Monthly backup (1st of month)
if [[ $(date +%d) -eq 1 ]]; then
    mkdir -p "$BACKUP_DIR/monthly"
    tar -czf "$BACKUP_DIR/monthly/backup-$(date +%Y%m).tar.gz" /data
fi

rotate_backups

#!/usr/bin/env bash
set -euo pipefail

verify_backup() {
    local backup_file="$1"

    echo "Verifying: $backup_file"

    # Check file exists and is not empty
    if [[ ! -s "$backup_file" ]]; then
        echo "FAIL: File is empty or missing"
        return 1
    fi

    # Check archive integrity
    if ! tar -tzf "$backup_file" >/dev/null 2>&1; then
        echo "FAIL: Archive is corrupted"
        return 1
    fi

    # Check file count
    local file_count
    file_count=$(tar -tzf "$backup_file" | wc -l)
    echo "  Files in archive: $file_count"

    if (( file_count < 10 )); then
        echo "WARN: Suspiciously few files"
        return 1
    fi

    echo "PASS: Backup is valid"
    return 0
}

# Verify all backups in directory
for backup in /backups/*.tar.gz; do
    verify_backup "$backup" || {
        echo "ALERT: Invalid backup found: $backup"
        # Send notification
    }
done