k8s中实现mysql主备
文章目录
- 一、k8s中实现mysql主备
-
- 1.1 环境信息
- 1.2 部署nfs-provisioner
-
- 1.2.1 安装nfs
- 1.2.2 部署nfs-provisioner
- 1.3 安装mysql
- 1.4 备库上查看是否同步
一、k8s中实现mysql主备
1.1 环境信息
| 机器 | 操作系统 | ip | mysql版本 | k8s版本 | storageClass |
|---|---|---|---|---|---|
| master1 | CentOS7.8 | 192.168.0.20 | mysql5.7.42 | 1.27.1 | nfs |
| node1 | CentOS7.8 | 192.168.0.21 | mysql5.7.42 | 1.27.1 | nfs |
1.2 部署nfs-provisioner
说明：
使用statefulSet部署双机MySQL，所以需要提供storageClass，这里使用nfs-provisioner。
1.2.1 安装nfs
这里nfs安装在node1节点上
mkdir /mnt/nfs && sh nfs_install.sh /mnt/nfs 192.168.0.0/24
nfs_install.sh
#!/bin/bash
### How to install it? ###
### 安装nfs-server，需要两个参数：1、挂载点 2、允许访问nfs-server的网段 ###
### How to use it? ###
### Client节点`yum -y install nfs-utils rpcbind`，然后挂载nfs-server目录到本地 ###
### 如：echo "192.168.0.20:/mnt/data01 /mnt/data01 nfs defaults 0 0" >> /etc/fstab && mount -a ###
mount_point=$1
subnet=$2
function nfs_server() {
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i 's/^SELINUX.*/SELINUX\=disabled/' /etc/selinux/config
yum -y install nfs-utils rpcbind
mkdir -p $mount_point
echo "$mount_point ${subnet}(rw,sync,no_root_squash)" >> /etc/exports
systemctl start rpcbind && systemctl enable rpcbind
systemctl restart nfs-server && systemctl enable nfs-server
chown -R nfsnobody:nfsnobody $mount_point
}
function usage() {
echo "Require 2 argument: [mount_point] [subnet]
eg: sh $0 /mnt/data01 192.168.10.0/24"
}
declare -i arg_nums
arg_nums=$#
if [ $arg_nums -eq 2 ];then
nfs_server
else
usage
exit 1
fi
1.2.2 部署nfs-provisioner
master1节点上执行 kubectl create namespace devops && kubectl apply -f nfs-provisioner.yaml
nfs-provisioner.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: nfs-provisioner
namespace: devops
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: nfs-provisioner-runner
rules:
- apiGroups: [""]
resources: ["persistentvolumes"]
verbs: ["get", "list", "watch", "create", "delete"]
- apiGroups: [""]
resources: ["persistentvolumeclaims"]
verbs: ["get", "list", "watch", "update"]
- apiGroups: ["storage.k8s.io"]
resources: ["storageclasses"]
verbs: ["get", "list", "watch"]
- apiGroups: [""]
resources: ["events"]
verbs: ["create", "update", "patch"]
- apiGroups: [""]
resources: ["services", "endpoints"]
verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: run-nfs-provisioner
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: nfs-provisioner-runner
subjects:
- kind: ServiceAccount
name: nfs-provisioner
namespace: devops
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
name: leader-locking-nfs-provisioner
namespace: devops
rules:
- apiGroups: [""]
resources: ["endpoints"]
verbs: ["get", "list", "watch", "create", "update", "patch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
name: leader-locking-nfs-provisioner
namespace: devops
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: leader-locking-nfs-provisioner
subjects:
- kind: ServiceAccount
name: nfs-provisioner
namespace: devops
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nfs-provisioner
namespace: devops
spec:
selector:
matchLabels:
app: nfs-provisioner
replicas: 1
strategy:
type: Recreate
template:
metadata:
labels:
app: nfs-provisioner
spec:
serviceAccountName: nfs-provisioner
containers:
- name: nfs-provisioner
image: docker.io/gmoney23/nfs-client-provisioner:latest
volumeMounts:
- name: nfs-client-root
mountPath: /persistentvolumes
env:
- name: PROVISIONER_NAME
value: example.com/nfs
- name: NFS_SERVER
value: 192.168.0.21
- name: NFS_PATH
value: /mnt/nfs
volumes:
- name: nfs-client-root
nfs:
server: 192.168.0.21
path: /mnt/nfs
---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: nfs
provisioner: example.com/nfs
#reclaimPolicy: Retain
1.3 安装mysql
kubectl apply -f deploy.yaml
deploy.yaml
apiVersion: v1
kind: Namespace
metadata:
name: mysql
labels:
app: mysql
---
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
namespace: mysql
labels:
app: mysql
data:
master.cnf: |
[client]
default-character-set=utf8mb4
[mysql]
default-character-set=utf8mb4
[mysqld]
max_connections=2000
default-time_zone='+8:00'
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
innodb_buffer_pool_size=536870912
datadir=/var/lib/mysql
pid-file=/var/run/mysqld/mysqld.pid
log-error=/var/lib/mysql/error.log
log-bin=mysqllog
skip-name-resolve
lower-case-table-names=1
log_bin_trust_function_creators=1
slave.cnf: |
[client]
default-character-set=utf8mb4
[mysql]
default-character-set=utf8mb4
[mysqld]
max_connections=2000
default-time_zone='+8:00'
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
innodb_buffer_pool_size=536870912
datadir=/var/lib/mysql
pid-file=/var/run/mysqld/mysqld.pid
log-error=/var/lib/mysql/error.log
super-read-only
skip-name-resolve
log-bin=mysql-bin
lower-case-table-names=1
log_bin_trust_function_creators=1
---
apiVersion: v1
kind: Secret
metadata:
name: mysql-secret
namespace: mysql
labels:
app: mysql
type: Opaque
data:
password: TnNiZzExMTEqQCE= # Nsbg1111*@!
replicationUser: Y29weQ== #copy
replicationPassword: TnNiZzExMTEqQCE= #Nsbg1111*@!
---
apiVersion: v1
kind: Service
metadata:
name: mysql
namespace: mysql
labels:
app: mysql
spec:
selector:
app: mysql
clusterIP: None
ports:
- name: mysql
port: 3306
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
namespace: mysql
labels:
app: mysql
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 2
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql
image: docker.io/library/mysql:5.7.42
command:
- bash
- "-c"
- |
set -ex
#从pod的hostname中通过正则获取序号，如果没有截取到就退出程序
ordinal=`cat /etc/hostname | awk -F"-" '{print $2}'` || exit 1
#将serverId输入到对应的配置文件中，路径可以随意（与之后的对应上就行），但是文件名不能换
echo [mysqld] > /etc/mysql/conf.d/server-id.cnf
# 由于server-id不能为0，因此给ID加100来避开它
server_id=$((100 + $ordinal))
echo "server-id=$server_id" >> /etc/mysql/conf.d/server-id.cnf
if [[ ${ordinal} -eq 0 ]]; then
# 如果Pod的序号为0，说明它是Master节点，从ConfigMap里把Master的配置文件拷贝到/mnt/conf.d目录下
cp /mnt/config-map/master.cnf /etc/mysql/conf.d
else
# 否则，拷贝ConfigMap里的Slave的配置文件
cp /mnt/config-map/slave.cnf /etc/mysql/conf.d
fi
echo "ending..."
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
- name: MYSQL_REPLICATION_USER
valueFrom:
secretKeyRef:
name: mysql-secret
key: replicationUser
- name: MYSQL_REPLICATION_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: replicationPassword
volumeMounts:
- name: conf
mountPath: /etc/mysql/conf.d
- name: config-map
mountPath: /mnt/config-map
containers:
- name: mysql
image: docker.io/library/mysql:5.7.42
lifecycle:
postStart:
exec:
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
#查看是否存在名为mysqlInitOk的文件，我们自己生产的标识文件，防止重复初始化集群
if [ ! -f mysqlInitOk ]; then
echo "Waiting for mysqld to be ready（accepting connections）"
#执行一条mysql的命令，查看mysql是否初始化完毕，如果没有就反复执行直到可以运行
#until mysql -uroot -p${MYSQL_ROOT_PASSWORD} -e "use mysql;SELECT 1;"; do sleep 1; done
sleep 5s
echo "Initialize ready"
#判断是master还是slave
pod_seq=`cat /etc/hostname | awk -F"-" '{print $2}'`
if [ $pod_seq -eq 0 ];then
#创建主从账户
mysql -uroot -p${MYSQL_ROOT_PASSWORD} -e "create user '${MYSQL_REPLICATION_USER}'@'%' identified by '${MYSQL_REPLICATION_PASSWORD}';"
#设置权限
mysql -uroot -p${MYSQL_ROOT_PASSWORD} -e "grant replication slave on *.* to '${MYSQL_REPLICATION_USER}'@'%' with grant option;"
#刷新配置
mysql -uroot -p${MYSQL_ROOT_PASSWORD} -e "flush privileges;"
#初始化master
mysql -uroot -p${MYSQL_ROOT_PASSWORD} -e "reset master;"
else
#设置slave连接的master
#mysql-0.mysql.mysql的由来{pod-name}.{service-name}.{namespace}
mysql -e \
"change master to master_host='mysql-0.mysql.mysql',master_port=3306, \
master_user='${MYSQL_REPLICATION_USER}',master_password='${MYSQL_REPLICATION_PASSWORD}', \
master_log_file='mysqllog.000001',master_log_pos=154;"
#重置slave
mysql -e "reset slave;"
#开始同步
mysql -e "start slave;"
#改成只读模式
mysql -e "set global read_only=1;"
fi
#运行完毕创建标识文件，防止重复初始化集群
touch mysqlInitOk
fi
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
- name: MYSQL_REPLICATION_USER
valueFrom:
secretKeyRef:
name: mysql-secret
key: replicationUser
- name: MYSQL_REPLICATION_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: replicationPassword
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
- name: conf
mountPath: /etc/mysql/conf.d
- name: run-mysql
mountPath: /var/run/mysql
resources:
requests:
cpu: 500m
memory: 2Gi
#设置存活探针
livenessProbe:
exec:
command: ["mysqladmin", "ping", "-uroot", "-p${MYSQL_ROOT_PASSWORD}"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
#设置就绪探针
readinessProbe:
exec:
command: ["mysqladmin", "ping", "-uroot", "-p${MYSQL_ROOT_PASSWORD}"]
initialDelaySeconds: 5
periodSeconds: 10
timeoutSeconds: 1
volumes:
- name: config-map
configMap:
name: mysql
volumeClaimTemplates:
- metadata:
name: data
spec:
accessModes:
- ReadWriteOnce
storageClassName: nfs
resources:
requests:
storage: 5Gi
- metadata:
name: conf
spec:
accessModes:
- ReadWriteOnce
storageClassName: nfs
resources:
requests:
storage: 100Mi
- metadata:
name: run-mysql
spec:
accessModes:
- ReadWriteOnce
storageClassName: nfs
resources:
requests:
storage: 100Mi
1.4 备库上查看是否同步
