kubernetes mysql一主多从部署
2022-09-28
7 min read
参考官方文档
1.准备pv
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-1
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-1
server: 192.168.234.131
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-2
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-2
server: 192.168.234.131
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-3
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-3
server: 192.168.234.131
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-4
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-4
server: 192.168.234.131
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-5
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-5
server: 192.168.234.131
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: mysql-datadir-6
namespace: test
spec:
capacity:
storage: 50Gi
accessModes:
- ReadWriteOnce
nfs:
path: /data/k8sdata/test/mysql-datadir-6
server: 192.168.234.131
2.创建一个ConfigMap
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
namespace: test
labels:
app: mysql
data:
master.cnf: |
# Apply this config only on the master.
[mysqld]#对应mysql配置可以根据实际的情况修改
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
3.创建service
# 为 StatefulSet 成员提供稳定的 DNS 表项的无头服务（Headless Service）
apiVersion: v1
kind: Service
metadata:
namespace: test
name: mysql
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
clusterIP: None
selector:
app: mysql
---
# 用于连接到任一 MySQL 实例执行读操作的客户端服务
# 对于写操作，你必须连接到主服务器：mysql-0.mysql
apiVersion: v1
kind: Service
metadata:
name: mysql-read
namespace: test
labels:
app: mysql
spec:
ports:
- name: mysql
port: 3306
selector:
app: mysql
4.创建StatefulSet
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
namespace: test
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 3
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql
image: 192.168.234.121/test/mysql@sha256:398f124948bb3d5789c0ac7c004d02e6d9a3ae95aa9804d7a3b33a344ff3c9cd
command:
- bash
- "-c"
- |
set -ex
# 基于 Pod 序号生成 MySQL 服务器的 ID
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
echo [mysqld] > /mnt/conf.d/server-id.cnf
# 添加偏移量以避免使用 server-id=0 这一保留值
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# 将合适的 conf.d 文件从 config-map 复制到 emptyDir
if [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/master.cnf /mnt/conf.d/
else
cp /mnt/config-map/slave.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: 192.168.234.121/test/xtrabackup@sha256:39f106eb400e18dcb4bded651a7ab308b39c305578ce228ae35f3c76bc715510
command:
- bash
- "-c"
- |
set -ex
# 如果已有数据，则跳过克隆
[[ -d /var/lib/mysql/mysql ]] && exit 0
# 跳过主实例（序号索引 0）的克隆
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# 从原来的对等节点克隆数据
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# 准备备份
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: 192.168.234.121/test/mysql@sha256:398f124948bb3d5789c0ac7c004d02e6d9a3ae95aa9804d7a3b33a344ff3c9cd
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "1"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
# 检查我们是否可以通过 TCP 执行查询(skip-networking 是关闭的)
command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: 192.168.234.121/test/xtrabackup@sha256:39f106eb400e18dcb4bded651a7ab308b39c305578ce228ae35f3c76bc715510
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# 确定克隆数据的 binlog 位置
if [[ -f xtrabackup_slave_info ]]; then
# XtraBackup 已经生成了部分的"CHANGE MASTER TO"查询
# 因为我们从一个现有副本进行克隆(需要删除末尾的分号!)
mv xtrabackup_slave_info change_master_to.sql.in
# 在这里要忽略 xtrabackup_binlog_info(它是没用的)
rm -f xtrabackup_binlog_info
elif [[ -f xtrabackup_binlog_info ]]; then
# 我们直接从主实例进行克隆。解析 binlog 位置.
[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || 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
# 检查我们是否需要通过启动复制来完成克隆.
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"
# 如果容器重新启动，最多尝试一次.
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
# 当对等点请求时，启动服务器发送备份.
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
5.部署完成查看
NAME READY STATUS RESTARTS AGE
mysql-0 2/2 Running 0 2m
mysql-1 2/2 Running 0 1m
mysql-2 2/2 Running 0 1m