随着互联网应用的不断发展和数据量的不断增加，数据库高可用性变得越来越重要。在Kubernetes（K8S）环境下，部署MySQL数据库并保证其高可用性是很常见的需求。本文将介绍如何使用keepalived实现MySQL数据库的高可用部署，旨在帮助新手快速入门。

### 步骤

| 步骤 | 操作 |
|------|--------|
| 1 | 安装MySQL数据库 |
| 2 | 配置MySQL主从复制 |
| 3 | 安装keepalived |
| 4 | 配置keepalived |

### 1. 安装MySQL数据库

首先在Kubernetes集群中安装MySQL数据库。可以使用Helm进行安装，以下是相关命令：

```bash
# 添加Bitnami仓库
helm repo add bitnami https://charts.bitnami.com/bitnami

# 安装MySQL
helm install my-release bitnami/mysql
```

### 2. 配置MySQL主从复制

在MySQL中配置主从复制，确保数据可以同步。以下是相关命令：

```sql
-- 在主节点上执行
GRANT REPLICATION SLAVE ON *.* TO 'slave_user'@'%' IDENTIFIED BY 'password';

-- 在从节点上执行
CHANGE MASTER TO
MASTER_HOST='master_host',
MASTER_USER='slave_user',
MASTER_PASSWORD='password',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=123;
START SLAVE;
```

### 3. 安装keepalived

接下来安装keepalived，用于实现虚拟IP的高可用切换，以下是相关命令：

```bash
# 在Kubernetes中创建keepalived服务
kubectl apply -f https://raw.githubusercontent.com/kubernetes/contrib/master/keepalived/deploy.yaml
```

### 4. 配置keepalived

最后配置keepalived，确保在MySQL主节点失效时能够自动切换到备用节点。以下是相关配置：

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: keepalived-cm
data:
keepalived.conf: |
vrrp_instance VI_1 {
state MASTER
interface {{VIP_INTERFACE}}
virtual_router_id 51
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
{{VIRTUAL_IP}}
}
}

---

apiVersion: apps/v1
kind: Deployment
metadata:
name: keepalived
spec:
replicas: 2
selector:
matchLabels:
app: keepalived
template:
metadata:
labels:
app: keepalived
spec:
containers:
- name: keepalived
image: osixia/keepalived:2.0.20
env:
- name: VIP_INTERFACE
value: "eth0"
- name: VIRTUAL_IP
value: "192.168.1.100"
volumeMounts:
- name: config
mountPath: /etc/keepalived/keepalived.conf
subPath: keepalived.conf
volumes:
- name: config
configMap:
name: keepalived-cm
```

以上配置将在Kubernetes中创建一个包含两个keepalived副本的Deployment，并配置虚拟IP及其切换规则。

通过以上步骤，我们就实现了MySQL数据库通过keepalived的高可用部署。希望通过这篇文章，新手能够快速掌握如何在Kubernetes环境下部署高可用的MySQL数据库。如有疑问可以留言进行讨论，我们一起进步！