#!/bin/bash

# Consul备份脚本
# 此脚本用于创建Consul的快照备份，并管理备份文件

set -e

# 配置参数
CONSUL_ADDR=${CONSUL_ADDR:-"http://localhost:8500"}
BACKUP_DIR=${BACKUP_DIR:-"/backups/consul"}
RETAIN_DAYS=${RETAIN_DAYS:-7}
DATE=$(date +%Y%m%d_%H%M%S)

# 创建备份目录
mkdir -p "$BACKUP_DIR"

echo "Consul备份脚本"
echo "==============="
echo "Consul地址: $CONSUL_ADDR"
echo "备份目录: $BACKUP_DIR"
echo "保留天数: $RETAIN_DAYS"
echo "备份时间: $DATE"
echo ""

# 检查Consul连接
check_consul_connection() {
    echo "检查Consul连接..."
    if curl -s "$CONSUL_ADDR/v1/status/leader" > /dev/null; then
        echo "✓ Consul连接正常"
    else
        echo "✗ 无法连接到Consul，请检查Consul服务是否运行"
        exit 1
    fi
}

# 创建快照备份
create_snapshot() {
    echo "创建Consul快照备份..."
    
    SNAPSHOT_FILE="${BACKUP_DIR}/consul-snapshot-${DATE}.snap"
    
    # 使用Consul API创建快照
    if curl -s "${CONSUL_ADDR}/v1/snapshot" > "$SNAPSHOT_FILE"; then
        echo "✓ 快照备份创建成功: $SNAPSHOT_FILE"
        
        # 显示快照信息
        echo "快照信息:"
        consul snapshot inspect "$SNAPSHOT_FILE" 2>/dev/null || echo "  (需要安装consul客户端以查看快照信息)"
    else
        echo "✗ 快照备份创建失败"
        exit 1
    fi
}

# 清理旧备份
cleanup_old_backups() {
    echo "清理${RETAIN_DAYS}天前的备份..."
    
    # 查找并删除旧备份文件
    if find "$BACKUP_DIR" -name "consul-snapshot-*.snap" -mtime +$RETAIN_DAYS -delete; then
        echo "✓ 旧备份清理完成"
    else
        echo "  没有找到需要清理的旧备份"
    fi
}

# 列出所有备份
list_backups() {
    echo ""
    echo "当前备份列表:"
    echo "============="
    
    if [ -d "$BACKUP_DIR" ] && [ "$(ls -A "$BACKUP_DIR")" ]; then
        ls -lah "$BACKUP_DIR"/consul-snapshot-*.snap | awk '{print $5, $6, $7, $8, $9}'
    else
        echo "  没有找到备份文件"
    fi
}

# 验证备份
verify_backup() {
    echo ""
    echo "验证备份..."
    
    LATEST_BACKUP=$(ls -t "$BACKUP_DIR"/consul-snapshot-*.snap | head -n 1)
    
    if [ -n "$LATEST_BACKUP" ]; then
        echo "验证最新备份: $LATEST_BACKUP"
        
        # 检查文件大小
        FILE_SIZE=$(du -h "$LATEST_BACKUP" | cut -f1)
        echo "备份文件大小: $FILE_SIZE"
        
        # 检查文件是否为空
        if [ -s "$LATEST_BACKUP" ]; then
            echo "✓ 备份文件不为空"
        else
            echo "✗ 备份文件为空"
            exit 1
        fi
        
        # 尝试检查快照元数据
        if consul snapshot inspect "$LATEST_BACKUP" > /dev/null 2>&1; then
            echo "✓ 备份文件格式正确"
        else
            echo "✗ 备份文件格式错误"
            exit 1
        fi
    else
        echo "✗ 没有找到备份文件"
        exit 1
    fi
}

# 主函数
main() {
    check_consul_connection
    create_snapshot
    cleanup_old_backups
    list_backups
    verify_backup
    
    echo ""
    echo "✓ 备份流程完成!"
    echo ""
    echo "使用说明:"
    echo "1. 可以通过cron定期运行此脚本: 0 2 * * * /path/to/backup_consul.sh"
    echo "2. 恢复备份使用: consul snapshot restore /path/to/consul-snapshot-YYYYMMDD_HHMMSS.snap"
    echo "3. 查看备份内容: consul snapshot inspect /path/to/consul-snapshot-YYYYMMDD_HHMMSS.snap"
}

# 执行主函数
main "$@"