版本
kubernetes：1.13.x
rook：1.1
mysql：5.7
参考
time.geekbang.org/column/arti…
集群的状态
- 是一个主从复制的mysql集群
- 有1个节点，多个从节点
- 从节点能水平扩展
- 所有的写操作，只能在主节点执行
- 读操作可以在所有节点执行
部署rook
我们使用rook作为mysql存储
#下载rook
[root@host1 ~]#git clone https://github.com/rook/rook.git
[root@host1 ~]# cd cd rook-master/cluster/examples/kubernetes/ceph/
[root@host1 ceph]# kubectl create -f common.yaml
[root@host1 ceph]kubectl create -f operator.yaml
[root@host1 ceph]kubectl create -f cluster.yaml
等一分钟左右
[root@host1 ceph]kubectl creat -f operator.yaml
注意是否有osd这几行，处于Complate状态是正常的。
如果有问题的话参考：rook.io/docs/rook/v…
apiVersion: ceph.rook.io/v1
kind: CephBlockPool
metadata:
name: replicapool
namespace: rook-ceph
spec:
failureDomain: host
replicated:
size: 3
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: rook-ceph-block
provisioner: ceph.rook.io/block
parameters:
blockPool: replicapool
# The value of "clusterNamespace" MUST be the same as the one in which your rook cluster exist
clusterNamespace: rook-ceph
# Specify the filesystem type of the volume. If not specified, it will use `ext4`.
fstype: xfs
# Optional, default reclaimPolicy is "Delete". Other options are: "Retain", "Recycle" as documented in https://kubernetes.io/docs/concepts/storage/storage-classes/
reclaimPolicy: Retain
# Optional, if you want to add dynamic resize for PVC. Works for Kubernetes 1.14+
# For now only ext3, ext4, xfs resize support provided, like in Kubernetes itself.
allowVolumeExpansion: true
在官方API文档上说明，要使用Flex驱动创建卷的话，要设置operator.yaml中ROOK_ENABLE_FLEX_DRIVER=true
[root@host1 ceph]# kubectl edit deployment -n rook-ceph
[root@host1 flex]# kubectl create storageclass.yaml
部署Mysql
ConfigMap
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
skip-grant-tables
kubectl create -f mysql-configmap.yaml
Service
# 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:
selector:
app: mysql
type: NodePort
ports:
- port: 3306
targetPort: 3306
nodePort: 30002
protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
name: mysql-master
labels:
app: mysql
spec:
selector:
app: mysql
type: NodePort
ports:
- port: 3306
targetPort: 3306
nodePort: 30001
protocol: TCP
kubectl create -f mysql-serive.yaml
StatefulSet
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mysql
spec:
selector:
matchLabels:
app: mysql
serviceName: mysql
replicas: 2
template:
metadata:
labels:
app: mysql
spec:
initContainers:
- name: init-mysql
image: mysql:5.7
command:
- bash
- "-c"
- |
set -ex
# hostname==Pod name，从Pod的序号，生成server-id
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
echo [mysqld] > /mnt/conf.d/server-id.cnf
# 由于server-id=0有特殊含义，所以我们给id+100避开
echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
# 如果Pod的序号是0，说明是Master节点，就把master.cnf拷贝到/mnt/conf.d目录下
# 否则为Slace节点，将slave.cnf拷贝到/mnt/conf.d目录下
if [[ $ordinal -eq 0 ]]; then
cp /mnt/config-map/master.cnf /mnt/conf.d/
else
cp /mnt/config-map/slave.cnf /mnt/conf.d/
fi
volumeMounts:
- name: conf
mountPath: /mnt/conf.d
- name: config-map
mountPath: /mnt/config-map
- name: clone-mysql
image: ist0ne/xtrabackup
command:
- bash
- "-c"
- |
set -ex
# 拷贝操作只需要在第一次启动时进行，如果数据已经存在的话，就跳过
[[ -d /var/lib/mysql/mysql ]] && exit 0
# 序号为0的Master不需要做这个操作，跳过
[[ `hostname` =~ -([0-9]+)$ ]] || exit 1
ordinal=${BASH_REMATCH[1]}
[[ $ordinal -eq 0 ]] && exit 0
# 使用ncat指令，远程地从前一个节点拷贝数据到本地
ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql
# 执行--prepare，这样拷贝来地数据就可以用作恢复了
xtrabackup --prepare --target-dir=/var/lib/mysql
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
containers:
- name: mysql
image: mysql:5.7
env:
- name: MYSQL_ROOT_PASSWORD
value: "isch1110"
ports:
- name: mysql
containerPort: 3306
volumeMounts:
- name: data
mountPath: /var/lib/mysql
subPath: mysql
- name: conf
mountPath: /etc/mysql/conf.d
resources:
requests:
cpu: 500m
memory: 1Gi
livenessProbe:
exec:
command: ["mysqladmin", "ping"]
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
readinessProbe:
exec:
# Check we can execute queries over TCP (skip-networking is off).
command: ["mysql", "-h", "127.0.0.1", "-u","root","-pisch1110","-e", "SELECT 1"]
initialDelaySeconds: 5
periodSeconds: 2
timeoutSeconds: 1
- name: xtrabackup
image: ist0ne/xtrabackup
ports:
- name: xtrabackup
containerPort: 3307
command:
- bash
- "-c"
- |
set -ex
cd /var/lib/mysql
# Determine binlog position of cloned data, if any.
if [[ -f xtrabackup_slave_info && "x$(<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 -u root -pisch1110 -e "SELECT 1"; do sleep 1; done
echo "Initializing replication from clone position"
mysql -h 127.0.0.1 -u root -pisch1110 \
-e "$(<change_master_to.sql.in), \
MASTER_HOST='mysql-0.mysql', \
MASTER_USER='root', \
MASTER_PASSWORD='isch1110'', \
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 --password=isch1110"
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:
storageClassName: rook-ceph-block
accessModes: ["ReadWriteOnce"]
resources:
requests:
storage: 10Gi
kubectl create -f mysql-statefulset.yaml
测试：
kubectl run mysql-client --image=mysql:5.7 -i --rm --restart=Never --\
mysql -h mysql-0.mysql <<EOF
CREATE DATABASE test;
CREATE TABLE test.messages (message VARCHAR(250));
INSERT INTO test.messages VALUES ('hello');
EOF
kubectl run mysql-client --image=mysql:5.7 -i -t --rm --restart=Never --\
mysql -h mysql-read -e "SELECT * FROM test.messages"
应该获得如下输出：
Waiting for pod default/mysql-client to be running, status is Pending, pod ready: false
+---------+
| message |
+---------+
| hello |
+---------+
pod "mysql-client" deleted
