特點:
headless service,無Cluster IP,名稱對應ep
網絡標識符固定且唯一
外部存儲固定持久化
對pod有序部署拓展,刪除終止,滾動更新
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 *
二進制日志的一個重要功能是主從復制,存儲函數有可能導致主從的數據不一致。開啟二進制日志后,配置文件參數log_bin_trust_function_creators永久生效,限制存儲函數的創建、修改、調用。
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名稱.deploy名稱.命名空間.k8s集群后綴 #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