1.准备mysql和xtrabackup镜像
下载mysql官方镜像并上传到本地harbor
docker pull mysql:5.7
docker tag m ysql:5.7 192.168.1.110/base/mysql:5.7
docker push 192.168.1.110/base/mysql:5.7
下载xtrabackup镜像并上传到本地harbor
docker pull registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0
docker tag registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0 192.168.1.110/base/xtrabackup:1.0
docker push 192.168.1.110/base/xtrabackup:1.0
2.为mysql数据目录准备PV
nfs创建目录
# mkdir /data/k8s-data/mysql/mysql-datadir-1 -p
# mkdir /data/k8s-data/mysql/mysql-datadir-2 -p
# mkdir /data/k8s-data/mysql/mysql-datadir-3 -p
# mkdir /data/k8s-data/mysql/mysql-datadir-4 -p
# mkdir /data/k8s-data/mysql/mysql-datadir-5 -p
编写pv的yaml
root@k8-deploy:~/k8s-yaml/mysql# cat pv/mysql-datadir-pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-1
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
nfs:
server: 192.168.2.10
path: /data/k8s-data/mysql/mysql-datadir-1
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-2
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
nfs:
server: 192.168.2.10
path: /data/k8s-data/mysql/mysql-datadir-2
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-3
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
nfs:
server: 192.168.2.10
path: /data/k8s-data/mysql/mysql-datadir-3
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-4
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
nfs:
server: 192.168.2.10
path: /data/k8s-data/mysql/mysql-datadir-4
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-5
spec:
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
nfs:
server: 192.168.2.10
path: /data/k8s-data/mysql/mysql-datadir-5
创建PV
root@k8-deploy:~/k8s-yaml/mysql# kubectl apply -f mysql-datadir-pv.yaml
persistentvolume/mysql-datadir-1 created
persistentvolume/mysql-datadir-2 created
persistentvolume/mysql-datadir-3 created
persistentvolume/mysql-datadir-4 created
persistentvolume/mysql-datadir-5 created
root@k8-deploy:~/k8s-yaml/mysql# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
mysql-datadir-1 10Gi RWO Retain Available 3s
mysql-datadir-2 10Gi RWO Retain Available 3s
mysql-datadir-3 10Gi RWO Retain Available 3s
mysql-datadir-4 10Gi RWO Retain Available 3s
mysql-datadir-5 10Gi RWO Retain Available 3s
3.部署StatefulSet的mysql集群
3.1 编写yaml文件
configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
labels:
app: mysql
data:
master.cnf: |
# Apply this config only on the master.
[mysqld]
log-bin
slave.cnf: |
# Apply this config only on slaves.
[mysqld]
super-read-only
mysql-services.yaml
Headless service for stable DNS entries of StatefulSet members.
apiVersion: v1
kind: Service
metadata:
name: mysql
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
clusterIP: None
selector:
app: mysql
---
# Client service for connecting to any MySQL instance for reads.
# For writes, you must instead connect to the master: mysql-0.mysql.
apiVersion: v1
kind: Service
metadata:
name: mysql-read
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
statefulset.yaml
# cat mysql-statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 3
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql
image: 192.168.1.110/base/mysql:5.7
command:
- bash
- "-c"
- |
set -ex
# Generate mysql server-id from pod ordinal index.
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
echo [mysqld] > /mnt/conf.d/server-id.cnf
# Add an offset to avoid reserved server-id=0 value.
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# Copy appropriate conf.d files from config-map to emptyDir.
if [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/master.cnf /mnt/conf.d/
else
cp /mnt/config-map/slave.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: 192.168.1.110/base/xtrabackup:1.0
command:
- bash
- "-c"
- |
set -ex
# Skip the clone if data already exists.
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Skip the clone on master (ordinal index 0).
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# Clone data from previous peer.
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# Prepare the backup.
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: 192.168.1.110/base/mysql:5.7
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "1"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
# Check we can execute queries over TCP (skip-networking is off).
command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: 192.168.1.110/base/xtrabackup:1.0
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then
# XtraBackup already generated a partial "CHANGE MASTER TO" query
# because we're cloning from an existing slave. (Need to remove the tailing semicolon!)
cat xtrabackup_slave_info | sed -E 's/;$//g' > change_master_to.sql.in
# Ignore xtrabackup_binlog_info in this case (it's useless).
rm -f xtrabackup_slave_info xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# We're cloning directly from master. Parse binlog position.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
rm -f xtrabackup_binlog_info xtrabackup_slave_info
echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in
fi
# Check if we need to complete a clone by starting replication.
if [[ -f change_master_to.sql.in ]]; then
echo "Waiting for mysqld to be ready (accepting connections)"
until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
mysql -h 127.0.0.1 \
-e "$(<change_master_to.sql.in), \
MASTER_HOST='mysql-0.mysql', \
MASTER_USER='root', \
MASTER_PASSWORD='', \
MASTER_CONNECT_RETRY=10; \
START SLAVE;" || exit 1
# In case of container restart, attempt this at-most-once.
mv change_master_to.sql.in change_master_to.sql.orig
fi
# Start a server to send backups when requested by peers.
exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \
"xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 100m
memory: 100Mi
volumes:
- name: conf
emptyDir: {}
- name: config-map
configMap:
name: mysql
volumeClaimTemplates:
- metadata:
name: data
spec:
accessModes: ["ReadWriteOnce"]
resources:
requests:
storage: 10Gi
3.2 创建集群
kubectl apply -f mysql-configmap.yaml
kubectl apply -f mysql-services.yaml
kubectl apply -f mysql-statefulset.yaml
3.3 测试集群
查看pod是否创建成功
root@k8-deploy:~/k8s-yaml/mysql# kubectl get pod
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 3m13s
mysql-1 2/2 Running 1 2m44s
mysql-2 2/2 Running 1 99s
进入pod查看挂载pv
root@k8-deploy:~/k8s-yaml/mysql# kubectl exec mysql-0 -it -- bash
root@mysql-0:/# df -h
Filesystem Size Used Avail Use% Mounted on
...
192.168.2.10:/data/k8s-data/mysql/mysql-datadir-4/mysql 98G 20G 74G 21% /var/lib/mysql
...
进入mysql-0 pod（mysql主）查看mysql状态，并创建测试数据库
root@mysql-0:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 148
Server version: 5.7.36-log MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-0-bin.000003
Position: 154
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)
ERROR:
No query specified
mysql> shwo databases;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'shwo databases' at line 1
mysql> show databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
+------------------------+
5 rows in set (0.04 sec)
mysql> create database yan_test;
Query OK, 1 row affected (0.02 sec)
mysql> show databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
| yan_test |
+------------------------+
6 rows in set (0.01 sec)
mysql> exit
依次查看其他从库的主从同步状态
root@mysql-1:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 140
Server version: 5.7.36 MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: mysql-0.mysql
Master_User: root
Master_Port: 3306
Connect_Retry: 10
Master_Log_File: mysql-0-bin.000003
Read_Master_Log_Pos: 325
Relay_Log_File: mysql-1-relay-bin.000002
Relay_Log_Pos: 493
Relay_Master_Log_File: mysql-0-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
mysql> show databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
| yan_test |
+------------------------+
6 rows in set (0.02 sec)
查看mysql的数据是否写入nfs
root@k8-deploy:~/k8s-yaml/mysql# tree -L 2 /data/k8s-data/mysql/
/data/k8s-data/mysql/
├── mysql-datadir-1
│ └── mysql
├── mysql-datadir-2
│ └── mysql
├── mysql-datadir-3
├── mysql-datadir-4
│ └── mysql
└── mysql-datadir-5
4.扩缩容测试
4.1 将集群副本增加到4个
root@k8-deploy:~/k8s-yaml/mysql# kubectl scale -n default statefulset mysql --replicas=4
statefulset.apps/mysql scaled
root@k8-deploy:~/k8s-yaml/mysql# kubectl get pod
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 13m
mysql-1 2/2 Running 1 12m
mysql-2 2/2 Running 1 11m
mysql-3 1/2 Running 1 24s
4.2 查看增加的mysql-3的主从状态
root@mysql-3:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 5.7.36 MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: mysql-0.mysql
Master_User: root
Master_Port: 3306
Connect_Retry: 10
Master_Log_File: mysql-0-bin.000003
Read_Master_Log_Pos: 325
Relay_Log_File: mysql-3-relay-bin.000002
Relay_Log_Pos: 322
Relay_Master_Log_File: mysql-0-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
mysql> show databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
| yan_test |
+------------------------+
6 rows in set (0.02 sec)
4.3 查看nfs mysql数据目录
root@k8-deploy:~/k8s-yaml/mysql# tree -L 2 /data/k8s-data/mysql/
/data/k8s-data/mysql/
├── mysql-datadir-1
│ └── mysql
├── mysql-datadir-2
│ └── mysql
├── mysql-datadir-3
│ └── mysql
├── mysql-datadir-4
│ └── mysql
└── mysql-datadir-5
9 directories, 0 files
4.4 将副本数缩容至2个
root@k8-deploy:~/k8s-yaml/mysql# kubectl scale -n default statefulset mysql --replicas=2
statefulset.apps/mysql scaled
4.4 查看pod缩容的过程（-w 参数）
root@k8-deploy:~/k8s-yaml/mysql# kubectl get pod -w
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 47m
mysql-1 2/2 Running 1 46m
mysql-2 2/2 Running 1 45m
mysql-3 2/2 Terminating 1 34m
mysql-3 0/2 Terminating 1 34m
mysql-3 0/2 Terminating 1 34m
mysql-3 0/2 Terminating 1 34m
mysql-2 2/2 Terminating 1 46m
root@k8-deploy:~/k8s-yaml/mysql# kubectl get pod
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 48m
mysql-1 2/2 Running 1 47m
4.4 再次查看mysql-1的主从状态是否正常。
# kubectl exec mysql-1 -it -- bash
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: mysql-0.mysql
Master_User: root
Master_Port: 3306
Connect_Retry: 10
Master_Log_File: mysql-0-bin.000003
Read_Master_Log_Pos: 325
Relay_Log_File: mysql-1-relay-bin.000002
Relay_Log_Pos: 493
Relay_Master_Log_File: mysql-0-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
4.4 缩容后再次查看nfs上mysql的数据目录（k8s并不会自动删除清理，需要手动操作）
root@k8-deploy:~/k8s-yaml/mysql# tree -L 2 /data/k8s-data/mysql/
/data/k8s-data/mysql/
├── mysql-datadir-1
│ └── mysql
├── mysql-datadir-2
│ └── mysql
├── mysql-datadir-3
│ └── mysql
├── mysql-datadir-4
│ └── mysql
└── mysql-datadir-5
9 directories, 0 files