详解MeterSphere 配置外部Mysql5.7的全过程
# 详解MeterSphere 配置外部Mysql5.7的全过程我从cnaaa.com购买了云服务器。
## 搭建一个主从复制（Master-Slave）的MySQL集群
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> !(https:////upload-images.jianshu.io/upload_images/27470379-e5d16b88ff6795eb.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1080/format/webp)
## 本地存储原理
> 这里使用了本地存储，也就是说，用户希望Kubernetes能够直接使用宿主机上的本地磁盘目录，而不依赖于远程存储服务，来提供持久化的容器Volume
>1、我们把存储固定在一个节点上，但是Pod在调度的时候，是飘来飘去的，怎么能让Pod通过PVC也能固定在PVC上？
>2、给这个Pod加上一个nodeAffinity行不行？
> 当然行，但是这变相破坏了开发人员对资源对象的定义规范了，开发人员应该不需要时刻考虑调度的细节。调度的改动应该交给运维就行。所以我们为了实现本地存储，我们采用了**延迟绑定**的方法。方法很简单，我们都知道StorageClass一般由运维人员设计，我们只需要在StorageClass指定no-provisioner。这是因为Local Persistent Volume目前尚不支持Dynamic Provisioning，所以它没办法在用户创建PVC的时候，就自动创建出对应的PV。与此同时，这个StorageClass还定义了一个volumeBindingMode=WaitForFirstConsumer的属性。它是Local Persistent Volume里一个非常重要的特性，即：延迟绑定。
## 创建PV
> 先在Node （实验用的Node节点IP是node1）节点上，预先分配几个PV（不建议在生产上这样操作），要保证在node1上有对应的目录
```css
ssh root@node1
mkdir -pv /data/svr/projects/{mysql,mysql2,mysql3}
```
###### vim 01-persistentVolume-1.yaml
```bash
apiVersion: v1
kind: PersistentVolume
metadata:
name: example-mysql-pv
spec:
capacity:
storage: 15Gi
volumeMode: Filesystem
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Delete
storageClassName: local-storage
local:
path: /data/svr/projects/mysql
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/hostname
operator: In
values:
- node1
```
###### vim 01-persistentVolume-2.yaml
```bash
apiVersion: v1
kind: PersistentVolume
metadata:
name: example-mysql-pv-2
spec:
capacity:
storage: 15Gi
volumeMode: Filesystem
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Delete
storageClassName: local-storage
local:
path: /data/svr/projects/mysql2
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/hostname
operator: In
values:
- node1
```
###### vim 01-persistentVolume-3.yaml
```bash
apiVersion: v1
kind: PersistentVolume
metadata:
name: example-mysql-pv-3
spec:
capacity:
storage: 15Gi
volumeMode: Filesystem
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Delete
storageClassName: local-storage
local:
path: /data/svr/projects/mysql3
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/hostname
operator: In
values:
- node1
```
> 记住，这是在生产上不推荐的做法，我只是实验用途才这样手动预先创建，**正规的做法应该通过StorageClass采用Dynamic Provisioning， 而不是Static Provisioning机制生产PV
```csharp
# kubectl apply -f 01-persistentVolume-1.yaml
persistentvolume/example-mysql-pv created
# kubectl apply -f 01-persistentVolume-2.yaml
persistentvolume/example-mysql-pv-2 created
# kubectl apply -f 01-persistentVolume-3.yaml
persistentvolume/example-mysql-pv-3 created
# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
example-mysql-pv 15Gi RWO Delete Available local-storage 8s
example-mysql-pv-2 15Gi RWO Delete Available local-storage 6s
example-mysql-pv-3 15Gi RWO Delete Available local-storage 3s
```
###### 02-storageclass.yaml
```bash
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer
```
```bash
# kubectl apply -f 02-storageclass.yaml
storageclass.storage.k8s.io/local-storage created
# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
local-storage kubernetes.io/no-provisioner Delete WaitForFirstConsumer false 5s
```
## 创建Namespace
###### 03-mysql-namespace.yaml
```php
apiVersion: v1
kind: Namespace
metadata:
name: mysql
labels:
app: mysql
```
```tsx
# kubectl apply -f 03-mysql-namespace.yaml
namespace/mysql unchanged
# kubectl get ns -n mysql
NAME STATUS AGE
mysql Active 3d
```
## 创建数据库的配置文件configmap
###### 使用ConfigMap为Master/Slave节点分配不同的配置文件
###### vim 04-mysql-configmap.yaml
```bash
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
namespace: mysql
labels:
app: mysql
data:
master.cnf: |
# Master配置
log-bin=mysqllog
skip-name-resolve
slave.cnf: |
# Slave配置
super-read-only
skip-name-resolve
log-bin=mysql-bin
replicate-ignore-db=mysql
```
```csharp
# kubectl apply -f 04-mysql-configmap.yaml
configmap/mysql created
# kubectl get cm -n mysql
NAME DATA AGE
mysql 2 5s
```
## 创建MySQL密码Secret
###### 05-mysql-secret.yaml
```cpp
apiVersion: v1
kind: Secret
metadata:
name: mysql-secret
namespace: mysql
labels:
app: mysql
type: Opaque
data:
password: MTIzNDU2 # echo -n "123456" | base64
```
```csharp
# kubectl apply -f 05-mysql-secret.yaml
secret/mysql-secret created
# kubectl get secret -n mysql
NAME TYPE DATA AGE
mysql-secret Opaque 1 18s
```
## 使用Service为MySQL提供读写分离
###### 06-mysql-services.yaml
```cpp
apiVersion: v1
kind: Service
metadata:
name: mysql
namespace: mysql
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
clusterIP: None
selector:
app: mysql
---
apiVersion: v1
kind: Service
metadata:
name: mysql-read
namespace: mysql
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
```
> 用户所有写请求，必须以DNS记录的方式直接访问到Master节点，也就是mysql-0.mysql这条DNS记录。
> 用户所有读请求，必须访问自动分配的DNS记录可以被转发到任意一个Master或Slave节点上，也就是mysql-read这条DNS记录。
```csharp
# kubectl apply -f 06-mysql-services.yaml
service/mysql created
service/mysql-read created
# kubectl get svc -n mysql
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
mysql ClusterIP None 3306/TCP 3s
mysql-read ClusterIP 10.107.90.19 3306/TCP 3s
```
## 创建MySQL集群实例
###### 使用StatefulSet搭建MySQL主从集群
###### 07-mysql-statefulset.yaml
```bash
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: mysql:5.7
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
command:
- bash
- "-c"
- |
set -ex
# 从Pod的序号，生成server-id
[[ $(hostname) =~ -(+)$ ]] || exit 1
ordinal=${BASH_REMATCH}
echo > /mnt/conf.d/server-id.cnf
# 由于server-id不能为0，因此给ID加100来避开它
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# 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
# 否则，拷贝ConfigMap里的Slave的配置文件
if [[ ${ordinal} -eq 0 ]]; then
cp /mnt/config-map/master.cnf /mnt/conf.d
else
cp /mnt/config-map/slave.cnf /mnt/conf.d
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: gcr.io/google-samples/xtrabackup:1.0
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
command:
- bash
- "-c"
- |
set -ex
# 拷贝操作只需要在第一次启动时进行，所以数据已经存在则跳过
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Master 节点（序号为 0）不需要这个操作
[[ $(hostname) =~ -(+)$ ]] || exit 1
ordinal=${BASH_REMATCH}
[[ $ordinal == 0 ]] && exit 0
# 使用ncat指令，远程地从前一个节点拷贝数据到本地
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# 执行 --prepare，这样拷贝来的数据就可以用作恢复了
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: mysql:5.7
env:
# - name: MYSQL_ALLOW_EMPTY_PASSWORD
# value: "1"
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping", "-uroot", "-p${MYSQL_ROOT_PASSWORD}"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
command: ["mysqladmin", "ping", "-uroot", "-p${MYSQL_ROOT_PASSWORD}"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: gcr.io/google-samples/xtrabackup:1.0
ports:
- name: xtrabackup
containerPort: 3307
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-secret
key: password
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# 从备份信息文件里读取MASTER_LOG_FILE和MASTER_LOG_POS这2个字段的值，用来拼装集群初始化SQL
if [[ -f xtrabackup_slave_info ]]; then
# 如果xtrabackup_slave_info文件存在，说明这个备份数据来自于另一个Slave节点
# 这种情况下，XtraBackup工具在备份的时候，就已经在这个文件里自动生成了“CHANGE MASTER TO”SQL语句
# 所以，只需要把这个文件重命名为change_master_to.sql.in，后面直接使用即可
mv xtrabackup_slave_info change_master_to.sql.in
# 所以，也就用不着xtrabackup_binlog_info了
rm -f xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# 如果只是存在xtrabackup_binlog_info文件，说明备份来自于Master节点，就需要解析这个备份信息文件，读取所需的两个字段的值
[[ $(cat xtrabackup_binlog_info) =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
rm xtrabackup_binlog_info
# 把两个字段的值拼装成SQL，写入change_master_to.sql.in文件
echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH}',\
MASTER_LOG_POS=${BASH_REMATCH}" > change_master_to.sql.in
fi
# 如果存在change_master_to.sql.in，就意味着需要做集群初始化工作
if [[ -f change_master_to.sql.in ]]; then
# 但一定要先等MySQL容器启动之后才能进行下一步连接MySQL的操作
echo "Waiting for mysqld to be ready（accepting connections）"
until mysql -h 127.0.0.1 -uroot -p${MYSQL_ROOT_PASSWORD} -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
# 将文件change_master_to.sql.in改个名字
# 防止这个Container重启的时候，因为又找到了change_master_to.sql.in，从而重复执行一遍初始化流程
mv change_master_to.sql.in change_master_to.sql.orig
# 使用change_master_to.sql.orig的内容，也就是前面拼装的SQL，组成一个完整的初始化和启动Slave的SQL语句
mysql -h 127.0.0.1 -uroot -p${MYSQL_ROOT_PASSWORD}整体的StatefulSet有两个Replicas，一个Master，一个Slave，然后使用init-mysql这个initContainers进行配置文件的初始化。接着使用clone-mysql这个initContainers进行数据的传输；同时使用xtrabackup这个**sidecar容器**进行SQL初始化和数据传输功能。
>创建 StatefulSet
```css
kubectl apply -f 07-mysql-statefulset.yaml
```
> 可以看到，StatefulSet启动成功后，会有两个Pod运行。接下来，我们可以尝试向这个MySQL集群 发起请求，执行一些SQL操作来验证它是否正常。整个过程因为拉取mysql和一个gcr.io/google-samples/xtrabackup:1.0国外的镜像会很慢,但是在创建mysql-0拉取一次之后，后续创建m>ysql-1就相对很快了。
>最后，容器检查pod的运行状态
```csharp
# kubectl get po -n mysql
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 2m7s
mysql-1 2/2 Running 0 116s
```
## 服务验证
###### 验证主从状态
```dart
# kubectl -n mysql exec mysql-1 -c mysql -- bash -c "mysql -uroot -p123456 -e 'show slave status \G'"
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: mysql-0.mysql.mysql
Master_User: root
Master_Port: 3306
Connect_Retry: 10
Master_Log_File: mysqllog.000003
Read_Master_Log_Pos: 154
Relay_Log_File: mysql-1-relay-bin.000002
Relay_Log_Pos: 319
Relay_Master_Log_File: mysqllog.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: mysql0
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 154
Relay_Log_Space: 528
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 100
Master_UUID: f8c7768a-6702-11ec-a648-c204e42fb62e
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
mysql: Using a password on the command line interface can be insecure.
```
###### 接下来，我们通过Master容器创建数据库和表、插入数据库
```swift
# kubectl -n mysql exec mysql-0 -c mysql -- bash -c "mysql -uroot -p123456 -e 'create database test'"
# kubectl -n mysql exec mysql-0 -c mysql -- bash -c "mysql -uroot -p123456 -e 'use test;create table counter(c int);'"
# kubectl -n mysql exec mysql-0 -c mysql -- bash -c "mysql -uroot -p123456 -e 'use test;insert into counter values(123)'"
# kubectl -n mysql exec mysql-1 -c mysql -- bash -c "mysql -uroot -p123456 -e 'use test;select * from counter'"
c
123
```
###### 当看到输出结果，主从同步正常了
###### 扩展节点
```csharp
# kubectl -n mysql scale statefulset mysql -—replicas=3
# kubectl get po -n mysql
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 11m
mysql-1 2/2 Running 0 11m
mysql-2 2/2 Running 0 20s
```
###### 查看扩容节点数据是否已同步
```swift
kubectl -n mysql exec mysql-2 -c mysql -- bash -c "mysql -uroot -p123456 -e 'use test;select * from counter’"
c
123
```
http://blog.itpub.net/70021605/viewspace-2916479/
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