k8s-使用statefulset部署mysql主从集群5.7
特点：
headless service,无Cluster IP,名称对应ep
网络标识符固定且唯一
外部存储固定持久化
对pod有序部署拓展，删除终止，滚动更新
https://kubernetes.io/zh/docs/tasks/run-application/run-replicated-stateful-application/
root@nfs-156~# showmount -e
Export list for ubuntu20.04.3.example.com:
/data/k8sdata *
二进制日志的一个重要功能是主从复制，存储函数有可能导致主从的数据不一致。开启二进制日志后，配置文件参数log_bin_trust_function_creators永久生效，限制存储函数的创建、修改、调用。
root@slave002# cat pv/mysql-persistentvolume.yaml
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-1
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-1
server: 192.168.192.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-2
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-2
server: 192.168.192.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-3
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-3
server: 192.168.192.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-4
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-4
server: 192.168.192.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-5
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-5
server: 192.168.192.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-6
namespace: chuan
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/chuan/mysql-datadir-6
server: 192.168.192.156
root@slave002l# kubectl get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE mysql-datadir-1 50Gi RWO Retain Bound chuan/data-mysql-0 12m mysql-datadir-2 50Gi RWO Retain Available 12m mysql-datadir-3 50Gi RWO Retain Bound chuan/data-mysql-1 12m mysql-datadir-4 50Gi RWO Retain Bound chuan/data-mysql-2 12m mysql-datadir-5 50Gi RWO Retain Available 12m mysql-datadir-6 50Gi RWO Retain Available 12m
root@slave002l# cat mysql-statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
namespace: chuan
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 3
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql
image: 192.168.192.155:80/chuan/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 [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/master.cnf /mnt/conf.d/
else
cp /mnt/config-map/slave.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: 192.168.192.155:80/chuan/xtrabackup:1.0
command:
- bash
- "-c"
- |
set -ex
# Skip the clone if data already exists.
[[ -d /var/lib/mysql/mysql ]] && exit 0
# Skip the clone on master (ordinal index 0).
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# Clone data from previous peer.
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# Prepare the backup.
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: 192.168.192.155:80/chuan/mysql:5.7
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "1"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
# Check we can execute queries over TCP (skip-networking is off).
command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: 192.168.192.155:80/chuan/xtrabackup:1.0
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info ]]; then
# XtraBackup already generated a partial "CHANGE MASTER TO" query
# because we're cloning from an existing slave.
mv xtrabackup_slave_info change_master_to.sql.in
# Ignore xtrabackup_binlog_info in this case (it's useless).
rm -f xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# We're cloning directly from master. Parse binlog position.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || 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
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
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.
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
root@slave002# cat mysql-services.yaml
# Headless service for stable DNS entries of StatefulSet members.
apiVersion: v1
kind: Service
metadata:
namespace: chuan
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: chuan
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
root@slave002# cat mysql-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
namespace: chuan
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
root@slave002# kubectl get po -nchuan NAME READY STATUS RESTARTS AGE mysql-0 2/2 Running 0 8m34s mysql-1 2/2 Running 1 8m19s mysql-2 2/2 Running 1 7m49s
root@slave002# kubectl get pvc -A NAMESPACE NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE chuan data-mysql-0 Bound mysql-datadir-1 50Gi RWO 9m37s chuan data-mysql-1 Bound mysql-datadir-3 50Gi RWO 9m22s chuan data-mysql-2 Bound mysql-datadir-4 50Gi RWO 8m52s
mysql> show slave status\G
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
PING mysql-2.mysql.chuan.svc.cluster.local (10.200.122.199): 56 data bytes
64 bytes from 10.200.122.199: seq=0 ttl=63 time=0.062 ms
pod名称.deploy名称.命名空间.k8s集群后缀 #解析pod地址非service
/ # ping web
PING web (10.100.204.137): 56 data bytes #解析service地址
root@slave002:/opt/k8s-data/k8s-data/yaml/chuan/mysql# kubectl get svc -nchuan NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE mysql ClusterIP None <none> 3306/TCP 15h mysql-read ClusterIP 10.100.204.47 <none> 3306/TCP 15h root@slave002:/opt/k8s-data/k8s-data/yaml/chuan/mysql# kubectl get ep -nchuan NAME ENDPOINTS AGE mysql 10.200.111.4:3306,10.200.122.199:3306,10.200.163.72:3306 15h mysql-read 10.200.111.4:3306,10.200.122.199:3306,10.200.163.72:3306 15h
