k8s实战案例之基于StatefulSet控制器运行MySQL一主多从
StatefulSet本质上是Deployment的⼀种变体，在v1.9版本中已成为GA版本，它为了解决有状态服务的问题，它所管理的Pod拥有固定的Pod名称，启停顺序，在StatefulSet中，Pod名字称为⽹络标识(hostname)，还必须要⽤到共享存储。在Deployment中，与之对应的服务是service，⽽在StatefulSet中与之对应的headless service，headless service，即⽆头服务，与service的区别就是它没有Cluster IP，解析它的名称时将返回该Headless Service对应的全部Pod的Endpoint列表。
1、前言
Pod调度运⾏时，如果应⽤不需要任何稳定的标示、有序的部署、删除和扩展，则应该使⽤⼀组⽆状态副本的控制器来部署应⽤，例如 Deployment 或 ReplicaSet更适合⽆状态服务需求，⽽StatefulSet适合管理所有有状态的服务，⽐如MySQL、MongoDB集群等。
2、StatefulSet控制器运行MySQL一主多从架构图
StatefulSet本质上是Deployment的⼀种变体，在v1.9版本中已成为GA版本，它为了解决有状态服务的问题，它所管理的Pod拥有固定的Pod名称，启停顺序，在StatefulSet中，Pod名字称为⽹络标识(hostname)，还必须要⽤到共享存储。
在Deployment中，与之对应的服务是service，⽽在StatefulSet中与之对应的headless service，headless service，即⽆头服务，与service的区别就是它没有Cluster IP，解析它的名称时将返回该Headless Service对应的全部Pod的Endpoint列表。
2.1、StatefulSet控制器特点
- 给每个pod分配固定且唯⼀的⽹络标识符
- 给每个pod分配固定且持久化的外部存储
- 对pod进⾏有序的部署和扩展
- 对pod进有序的删除和终⽌
- 对pod进有序的⾃动滚动更新
2.2、StatefulSet的组成部分
- Headless Service：⽤来定义Pod⽹络标识( DNS domain)，指的是短的service(丢失了domainname)。
- StatefulSet：定义具体应⽤，有多少个Pod副本，并为每个Pod定义了⼀个域名。
- volumeClaimTemplates： 存储卷申请模板，创建PVC，指定pvc名称⼤⼩，将⾃动创建pvc，且pvc必须由存储类供应。
3、在k8s上部署mysql一主多从
3.1、基础镜像准备
3.1.1、准备mysql镜像
下载镜像
root@k8s-master01:~# nerdctl pull mysql:5.7.36
修改镜像tag为本地harbor地址
root@k8s-master01:~# nerdctl tag mysql:5.7.36 harbor.ik8s.cc/magedu/mysql:5.7.36
上传镜像至本地harbor
root@k8s-master01:~# nerdctl push harbor.ik8s.cc/magedu/mysql:5.7.36
3.1.2、准备xtrabackup镜像
下载镜像
root@k8s-master01:~# nerdctl pull registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0
修改镜像tag为本地harbor地址
root@k8s-master01:~# nerdctl tag registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0 harbor.ik8s.cc/magedu/xtrabackup:1.0
上传镜像至本地harbor
root@k8s-master01:~# nerdctl push harbor.ik8s.cc/magedu/xtrabackup:1.0
3.1.3、验证镜像是否上传至harbor？
3.2、准备pv
3.2.1、在nfs服务器上创建数据存储目录
root@harbor:~# mkdir -pv /data/k8sdata/magedu/mysql-datadir-{1..5}
mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-1'
mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-2'
mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-3'
mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-4'
mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-5'
root@harbor:~#
3.2.2、在nfs服务器上导出数据存储目录
root@harbor:/data/k8sdata/magedu# cat /etc/exports
# /etc/exports: the access control list for filesystems which may be exported
# to NFS clients. See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check)
#
/data/k8sdata/kuboard *(rw,no_root_squash)
/data/volumes *(rw,no_root_squash)
/pod-vol *(rw,no_root_squash)
/data/k8sdata/myserver *(rw,no_root_squash)
/data/k8sdata/mysite *(rw,no_root_squash)
/data/k8sdata/magedu/images *(rw,no_root_squash)
/data/k8sdata/magedu/static *(rw,no_root_squash)
/data/k8sdata/magedu/zookeeper-datadir-1 *(rw,no_root_squash)
/data/k8sdata/magedu/zookeeper-datadir-2 *(rw,no_root_squash)
/data/k8sdata/magedu/zookeeper-datadir-3 *(rw,no_root_squash)
/data/k8sdata/magedu/redis-datadir-1 *(rw,no_root_squash)
/data/k8sdata/magedu/redis0 *(rw,no_root_squash)
/data/k8sdata/magedu/redis1 *(rw,no_root_squash)
/data/k8sdata/magedu/redis2 *(rw,no_root_squash)
/data/k8sdata/magedu/redis3 *(rw,no_root_squash)
/data/k8sdata/magedu/redis4 *(rw,no_root_squash)
/data/k8sdata/magedu/redis5 *(rw,no_root_squash)
/data/k8sdata/magedu/mysql-datadir-1 *(rw,no_root_squash)
/data/k8sdata/magedu/mysql-datadir-2 *(rw,no_root_squash)
/data/k8sdata/magedu/mysql-datadir-3 *(rw,no_root_squash)
/data/k8sdata/magedu/mysql-datadir-4 *(rw,no_root_squash)
/data/k8sdata/magedu/mysql-datadir-5 *(rw,no_root_squash)
root@harbor:/data/k8sdata/magedu# exportfs -av
exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/kuboard".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [2]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/volumes".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [3]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/pod-vol".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [4]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/myserver".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [5]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/mysite".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [7]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/images".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [8]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/static".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [11]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-1".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [12]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-2".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [13]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-3".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [16]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis-datadir-1".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [18]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis0".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [19]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis1".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [20]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis2".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [21]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis3".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [22]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis4".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [23]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis5".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [27]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-1".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [28]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-2".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [29]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-3".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [30]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-4".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exportfs: /etc/exports [31]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-5".
Assuming default behaviour ('no_subtree_check').
NOTE: this default has changed since nfs-utils version 1.0.x
exporting *:/data/k8sdata/magedu/mysql-datadir-5
exporting *:/data/k8sdata/magedu/mysql-datadir-4
exporting *:/data/k8sdata/magedu/mysql-datadir-3
exporting *:/data/k8sdata/magedu/mysql-datadir-2
exporting *:/data/k8sdata/magedu/mysql-datadir-1
exporting *:/data/k8sdata/magedu/redis5
exporting *:/data/k8sdata/magedu/redis4
exporting *:/data/k8sdata/magedu/redis3
exporting *:/data/k8sdata/magedu/redis2
exporting *:/data/k8sdata/magedu/redis1
exporting *:/data/k8sdata/magedu/redis0
exporting *:/data/k8sdata/magedu/redis-datadir-1
exporting *:/data/k8sdata/magedu/zookeeper-datadir-3
exporting *:/data/k8sdata/magedu/zookeeper-datadir-2
exporting *:/data/k8sdata/magedu/zookeeper-datadir-1
exporting *:/data/k8sdata/magedu/static
exporting *:/data/k8sdata/magedu/images
exporting *:/data/k8sdata/mysite
exporting *:/data/k8sdata/myserver
exporting *:/pod-vol
exporting *:/data/volumes
exporting *:/data/k8sdata/kuboard
root@harbor:/data/k8sdata/magedu#
3.2.2、创建pv
创建pv配置清单
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-1
namespace: magedu
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/magedu/mysql-datadir-1
server: 192.168.0.42
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-2
namespace: magedu
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/magedu/mysql-datadir-2
server: 192.168.0.42
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-3
namespace: magedu
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/magedu/mysql-datadir-3
server: 192.168.0.42
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-4
namespace: magedu
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/magedu/mysql-datadir-4
server: 192.168.0.42
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-5
namespace: magedu
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/magedu/mysql-datadir-5
server: 192.168.0.42
创建pv
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl apply -f pv/mysql-persistentvolume.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@k8s-master01:~/k8s-data/yaml/magedu/mysql#
3.2.3、验证pv
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
mysql-datadir-1 50Gi RWO Retain Available 5s
mysql-datadir-2 50Gi RWO Retain Available 5s
mysql-datadir-3 50Gi RWO Retain Available 5s
mysql-datadir-4 50Gi RWO Retain Available 5s
mysql-datadir-5 50Gi RWO Retain Available 5s
redis-cluster-pv0 5Gi RWO Retain Bound magedu/data-redis-1 8d
redis-cluster-pv1 5Gi RWO Retain Bound magedu/data-redis-3 8d
redis-cluster-pv2 5Gi RWO Retain Bound magedu/data-redis-4 8d
redis-cluster-pv3 5Gi RWO Retain Bound magedu/data-redis-0 8d
redis-cluster-pv4 5Gi RWO Retain Bound magedu/data-redis-5 8d
redis-cluster-pv5 5Gi RWO Retain Bound magedu/data-redis-2 8d
redis-datadir-pv-1 10Gi RWO Retain Bound magedu/redis-datadir-pvc-1 9d
zookeeper-datadir-pv-1 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-1 10d
zookeeper-datadir-pv-2 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-2 10d
zookeeper-datadir-pv-3 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-3 10d
root@k8s-master01:~/k8s-data/yaml/magedu/mysql#
3.3、运行mysql服务
MYSQL CONFIGMAP配置清单
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
namespace: magedu
labels:
app: mysql
data:
master.cnf: |
# Apply this config only on the master.
[mysqld]
log-bin
log_bin_trust_function_creators=1
lower_case_table_names=1
slave.cnf: |
# Apply this config only on slaves.
[mysqld]
super-read-only
log_bin_trust_function_creators=1
MYSQL POD配置清单
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
namespace: magedu
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 2
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql #初始化容器1、基于当前pod name匹配角色是master还是slave，并动态生成相对应的配置文件
image: harbor.ik8s.cc/magedu/mysql:5.7.36
command:
- bash
- "-c"
- |
set -ex
# Generate mysql server-id from pod ordinal index.
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1 #匹配hostname的最后一位、最后是一个顺序叠加的整数
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 [[ $ordinal -eq 0 ]]; then #如果是master、则cpmaster配置文件
cp /mnt/config-map/master.cnf /mnt/conf.d/
else #否则cp slave配置文件
cp /mnt/config-map/slave.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf #临时卷、emptyDir
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql #初始化容器2、用于生成mysql配置文件、并从上一个pod完成首次的全量数据clone(slave 3从slave2 clone，而不是每个slave都从master clone实现首次全量同步,但是后期都是与master实现增量同步)
image: harbor.ik8s.cc/magedu/xtrabackup:1.0
command:
- bash
- "-c"
- |
set -ex
# Skip the clone if data already exists.
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Skip the clone on master (ordinal index 0).
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0 #如果最后一位是0(master)则退出clone过程
# Clone data from previous peer.
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql #从上一个pod执行clone(binlog),xbstream为解压缩命令
# Prepare the backup.xue
xtrabackup --prepare --target-dir=/var/lib/mysql #通过xtrabackup恢复binlog
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql #业务容器1(mysql主容器)
image: harbor.ik8s.cc/magedu/mysql:5.7.36
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "1"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data #挂载数据目录至/var/lib/mysql
mountPath: /var/lib/mysql
subPath: mysql
- name: conf #配置文件/etc/mysql/conf.d
mountPath: /etc/mysql/conf.d
resources: #资源限制
requests:
cpu: 500m
memory: 1Gi
livenessProbe: #存活探针
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe: #就绪探针
exec:
# Check we can execute queries over TCP (skip-networking is off).
command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup #业务容器2(xtrabackup),用于后期同步master 的binglog并恢复数据
image: harbor.ik8s.cc/magedu/xtrabackup:1.0
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info ]]; then
# XtraBackup already generated a partial "CHANGE MASTER TO" query
# because we're cloning from an existing slave.
mv xtrabackup_slave_info change_master_to.sql.in
# Ignore xtrabackup_binlog_info in this case (it's useless).
rm -f xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# We're cloning directly from master. Parse binlog position.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
rm xtrabackup_binlog_info
echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in #生成CHANGE MASTER命令
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"
# In case of container restart, attempt this at-most-once.
mv change_master_to.sql.in change_master_to.sql.orig
#执行CHANGE MASTER操作并启动SLAVE
mysql -h 127.0.0.1 <<EOF
$(<change_master_to.sql.orig),
MASTER_HOST='mysql-0.mysql',
MASTER_USER='root',
MASTER_PASSWORD='',
MASTER_CONNECT_RETRY=10;
START SLAVE;
EOF
fi
# Start a server to send backups when requested by peers. #监听在3307端口，用于为下一个pod同步全量数据
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
上述配置清单主要定义两个mysqlPod，其中每个pod中运行4个容器，第一个容器init容器主要目的是通过sts控制器创建pod的名称id来确定挂载master和slave配置；第二个初始化容器主要目的是用于克隆上一个pod的数据，即salve1从master上克隆数据，slave2从slave1克隆数据，以此类推；第三个就是mysql主容器，运行mysql实例；第四个容器主要用于给mysql主容器同步后期的增量数据的；
MYSQL SERVICE配置清单
# Headless service for stable DNS entries of StatefulSet members.
apiVersion: v1
kind: Service
metadata:
namespace: magedu
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
namespace: magedu
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
上述配置清单主要创建了两个service，第一个是一个无头service 用户返回后端所有pod端点；第二个service是一个默认clusterip类型service，这两个service都是可以的；
3.3.1、创建mysql pod
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl apply -f mysql-configmap.yaml -f mysql-services.yaml -f mysql-statefulset.yaml
configmap/mysql created
service/mysql created
service/mysql-read created
statefulset.apps/mysql created
root@k8s-master01:~/k8s-data/yaml/magedu/mysql#
3.3.2、验证MySQL Pod状态
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl get pods -n magedu
NAME READY STATUS RESTARTS AGE
magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (113m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (114m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (114m ago) 11d
mysql-0 2/2 Running 0 47s
mysql-1 2/2 Running 0 23s
redis-0 1/1 Running 2 (114m ago) 8d
redis-1 1/1 Running 2 (114m ago) 8d
redis-2 1/1 Running 2 (114m ago) 8d
redis-3 1/1 Running 2 (114m ago) 8d
redis-4 1/1 Running 2 (114m ago) 8d
redis-5 1/1 Running 2 (114m ago) 8d
ubuntu1804 0/1 Completed 0 8d
zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (114m ago) 10d
zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (114m ago) 10d
zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (114m ago) 10d
root@k8s-master01:~/k8s-data/yaml/magedu/mysql#
修改配置清单pod副本为3，看看对应pod是否能够正常running?
应用配置清单
3.3.3、验证MySQL主从同步是否正常
验证master状态
root@k8s-master01:~# kubectl exec -it mysql-0 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-0:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 691
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: 313
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.01 sec)
mysql> exit
Bye
root@mysql-0:/# exit
exit
root@k8s-master01:~#
验证slave状态
root@k8s-master01:~# kubectl exec -it mysql-1 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-1:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 708
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: 313
Relay_Log_File: mysql-1-relay-bin.000002
Relay_Log_Pos: 481
Relay_Master_Log_File: mysql-0-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
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: 313
Relay_Log_Space: 690
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: 72724f41-0b65-11ee-b561-16065cd6961a
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:
1 row in set (0.00 sec)
mysql> exit
Bye
root@mysql-1:/# exit
exit
root@k8s-master01:~# kubectl exec -it mysql-2 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-2:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 632
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: 313
Relay_Log_File: mysql-2-relay-bin.000002
Relay_Log_Pos: 481
Relay_Master_Log_File: mysql-0-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
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: 313
Relay_Log_Space: 690
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: 72724f41-0b65-11ee-b561-16065cd6961a
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:
1 row in set (0.00 sec)
mysql> exit
Bye
root@mysql-2:/# exit
exit
root@k8s-master01:~#
能够在slave上看到IO和SQL线程正常running，说明slave状态没有问题；
进入mysql-0创建数据库
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-0 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-0:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 355
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 databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
+------------------------+
5 rows in set (0.02 sec)
mysql> create database mydb;
Query OK, 1 row affected (0.00 sec)
mysql> show databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mydb |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
+------------------------+
6 rows in set (0.00 sec)
mysql>
在slave pod中验证数据是否同步？
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-1 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-1:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 437
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 databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mydb |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
+------------------------+
6 rows in set (0.01 sec)
mysql> exit
Bye
root@mysql-1:/# exit
exit
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-2 -n magedu bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init)
root@mysql-2:/# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 361
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 databases;
+------------------------+
| Database |
+------------------------+
| information_schema |
| mydb |
| mysql |
| performance_schema |
| sys |
| xtrabackup_backupfiles |
+------------------------+
6 rows in set (0.02 sec)
mysql> exit
Bye
root@mysql-2:/# exit
exit
root@k8s-master01:~/k8s-data/yaml/magedu/mysql#
能够通过上述在主库创建数据库，从库能够正常同步，则说明mysql主从同步没有问题；
3.3.4、mysql⾼可⽤测试
3.3.4.1、删除master pod验证mysql高可用性
进入master，验证master数据是否丢失？
能够看到master数据并未丢失，这是因为该数据存放至远端nfs存储之上；
3.3.4.2、删除slave pod验证mysql高可用性
root@k8s-master01:~# kubectl get pods -n magedu
NAME READY STATUS RESTARTS AGE
magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (143m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (143m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (143m ago) 11d
mysql-0 2/2 Running 0 3m6s
mysql-1 2/2 Running 0 29m
mysql-2 2/2 Running 0 27m
redis-0 1/1 Running 2 (143m ago) 8d
redis-1 1/1 Running 2 (143m ago) 8d
redis-2 1/1 Running 2 (143m ago) 8d
redis-3 1/1 Running 2 (143m ago) 8d
redis-4 1/1 Running 2 (143m ago) 8d
redis-5 1/1 Running 2 (143m ago) 8d
ubuntu1804 0/1 Completed 0 8d
zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (143m ago) 10d
zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (143m ago) 10d
zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (143m ago) 10d
root@k8s-master01:~# kubectl delete pods mysql-1 -n magedu
pod "mysql-1" deleted
root@k8s-master01:~# kubectl get pods -n magedu
NAME READY STATUS RESTARTS AGE
magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (144m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (145m ago) 11d
magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (145m ago) 11d
mysql-0 2/2 Running 0 4m55s
mysql-1 2/2 Running 0 55s
mysql-2 2/2 Running 0 28m
redis-0 1/1 Running 2 (145m ago) 8d
redis-1 1/1 Running 2 (145m ago) 8d
redis-2 1/1 Running 2 (145m ago) 8d
redis-3 1/1 Running 2 (145m ago) 8d
redis-4 1/1 Running 2 (145m ago) 8d
redis-5 1/1 Running 2 (145m ago) 8d
ubuntu1804 0/1 Completed 0 8d
zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (145m ago) 10d
zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (145m ago) 10d
zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (145m ago) 10d
root@k8s-master01:~#
进入slave验证数据
作者：Linux-1874
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利.
