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Implementation of k8s redis one master multi slave dynamic capacity expansion

2022-04-23 17:55:00 【Wangzi_ milk】

framework

be based on statefulset Realize one master and many slaves redis, Dynamic expansion and contraction redis Slave Library , And based on storageclass Realize dynamic storage , Ensure the persistent storage of data

Insert picture description here

Host name	IP
k8s-master-1	192.168.0.10
k8s-node-1	192.168.0.11
k8s-nfs	192.168.0.55

nfs-provider

# k8s-nfs nfs Configuration information 
[[email protected] ~]# cat /etc/exports
/data	192.168.0.0/24(rw,all_squash)

[[email protected]-master-1 1master-Nslave]# cat nfs-provider.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: redis
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "delete"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create", "update", "patch"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: run-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: redis
roleRef:
  kind: ClusterRole
  name: nfs-client-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: redis
rules:
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: redis
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: redis
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: redis
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      nodeName: k8s-master-1   # Set in the master Node operation 
      tolerations:             # Set tolerance master Node stains 
      - key: node-role.kubernetes.io/master
        operator: Equal
        value: "true"
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: registry.cn-hangzhou.aliyuncs.com/jiayu-kubernetes/nfs-subdir-external-provisioner:v4.0.0
          imagePullPolicy: IfNotPresent
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s/nfs-subdir-external-provisioner
            - name: NFS_SERVER
              value: 192.168.0.55
            - name: NFS_PATH
              value: /data
      volumes:
        - name: nfs-client-root
          nfs:
            server: 192.168.0.55  # NFS SERVER_IP
            path: /data
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: redis-nfs
  namespace: redis
  annotations:
    storageclass.kubernetes.io/is-default-class: "false"  #  Whether to set as the default storageclass
provisioner: k8s/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME'
allowVolumeExpansion: true
reclaimPolicy: Delete
parameters:
  archiveOnDelete: "false"

redis.conf

[[email protected]-master-1 1master-Nslave]# cat configmap.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: redis
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: redis
  namespace: redis
data:
  redis.conf: |-
    daemonize no
    protected-mode no
    bind 0.0.0.0
    port 6379
    timeout 300
    databases 16
    save 900 1
    save 300 10
    save 60 10000 
    loglevel notice
    logfile /data/redis.log
    ################### RDB ####################
    dir /data
    stop-writes-on-bgsave-error yes
    rdbcompression yes
    dbfilename dump.rdb
    ################## REPL ################### 
    slave-read-only yes
    repl-diskless-sync no
    repl-timeout 120
    ################## SECURITY ###################
    requirepass 123456
    masterauth 123456
    ################## AOF ####################
    appendonly no
    appendfilename "appendonly.aof"
    appendfsync no

statefulset

[[email protected]-master-1 1master-Nslave]# cat statefulset.yaml 
apiVersion: v1
kind: Service
metadata:
  name: redis
  namespace: redis
spec:
  selector:
    app: redis
  ports:
  - name: redis
    port: 6379
    targetPort: 6379
    protocol: TCP
  clusterIP: None
  type: ClusterIP
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis
  namespace: redis
spec:
  replicas: 2                  				 #  The default is one master and one slave 
  selector:
    matchLabels:
      app: redis
  serviceName: redis
  template:
    metadata:
      labels:
        app: redis
    spec:
      containers:
      - name: redis
        image: redis:5
        imagePullPolicy: IfNotPresent
        command:
        - /bin/sh
        - -c
        - | set -e hostname=$(echo `hostname` | grep -oE '\-([0-9]+)$') if [ "$hostname" != "-0" ]; then # If it's not the first node , Synchronize to the first node  redis-server /etc/redis.conf slaveof redis-0.redis.redis.svc.cluster.local 6379 else redis-server /etc/redis.conf fi
        volumeMounts:
        - name: redis-data
          mountPath: /data
        - name: redis-conf
          mountPath: /etc/redis.conf
          subPath: redis.conf
      volumes:
      - name: redis-conf
        configMap:
          name: redis
  volumeClaimTemplates:
  - metadata:
      name: redis-data
      namespace: redis
    spec:
      accessModes: ["ReadWriteMany"]
      storageClassName: redis-nfs
      resources:
        requests:
          storage: 500Mi

Deploy

#  Deploy configmap
[[email protected] 1master-Nslave]# kubectl apply -f configmap.yaml 
namespace/redis created
configmap/redis created

#  Deploy nfs-provider
[[email protected] 1master-Nslave]# kubectl apply -f nfs-provider.yaml 
serviceaccount/nfs-client-provisioner created
clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
role.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
rolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
deployment.apps/nfs-client-provisioner created
storageclass.storage.k8s.io/redis-nfs created

#  Deploy statefulset
[[email protected] 1master-Nslave]# kubectl apply -f statefulset.yaml 
service/redis created
statefulset.apps/redis created

#  see pod
[[email protected] 1master-Nslave]# kubectl get pods -n redis
NAME                                      READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-7f6758d967-l9b5p   1/1     Running   0          2m10s
redis-0                                   1/1     Running   0          100s
redis-1                                   1/1     Running   0          53s

#  see PV,PVC
[[email protected] 1master-Nslave]# kubectl get pvc -n redis
NAME                 STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
redis-data-redis-0   Bound    pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            redis-nfs      2m21s
redis-data-redis-1   Bound    pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            redis-nfs      94s
[[email protected] 1master-Nslave]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                      STORAGECLASS   REASON   AGE
pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            Delete           Bound    redis/redis-data-redis-1   redis-nfs               96s
pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            Delete           Bound    redis/redis-data-redis-0   redis-nfs               2m23s


# k8s-nfs Node view 
[[email protected] ~]# ls /data
redis-redis-data-redis-0-pvc-e0642424-f6b3-405f-9d12-d53b277be042  redis-redis-data-redis-1-pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6


#  see redis-1 Replication 
[[email protected] 1master-Nslave]# kubectl exec redis-1 -n redis -- redis-cli -a 123456 info replication
# Replication
role:slave  # Slave Library 
master_host:redis-0.redis.redis.svc.cluster.local  # Main library information 
master_port:6379
master_link_status:up
master_last_io_seconds_ago:7
master_sync_in_progress:0
slave_repl_offset:252
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:03c3dd18042139cbe116946f6c46c640fb91681b
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:252
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:252

Capacity expansion

Expansion from redis-0->redis-N

#  Capacity expansion 
[[email protected] 1master-Nslave]# kubectl scale statefulset redis --replicas=4 -n redis
statefulset.apps/redis scaled

#  see pod
[[email protected] 1master-Nslave]# kubectl get pods -n redis
NAME                                      READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-7f6758d967-l9b5p   1/1     Running   0          6m52s
redis-0                                   1/1     Running   0          6m22s
redis-1                                   1/1     Running   0          5m35s
redis-2                                   1/1     Running   0          16s
redis-3                                   1/1     Running   0          11s

#  so pvc,pv It's all dynamically generated 
[[email protected] 1master-Nslave]# kubectl get pvc -n redis
NAME                 STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
redis-data-redis-0   Bound    pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            redis-nfs      7m
redis-data-redis-1   Bound    pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            redis-nfs      6m13s
redis-data-redis-2   Bound    pvc-521d77ec-64df-44e1-8a49-22d032046b86   500Mi      RWX            redis-nfs      54s
redis-data-redis-3   Bound    pvc-365be101-2ced-4800-9db0-be68fdedd64d   500Mi      RWX            redis-nfs      49s
[[email protected] 1master-Nslave]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                      STORAGECLASS   REASON   AGE
pvc-365be101-2ced-4800-9db0-be68fdedd64d   500Mi      RWX            Delete           Bound    redis/redis-data-redis-3   redis-nfs               55s
pvc-521d77ec-64df-44e1-8a49-22d032046b86   500Mi      RWX            Delete           Bound    redis/redis-data-redis-2   redis-nfs               60s
pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            Delete           Bound    redis/redis-data-redis-1   redis-nfs               6m19s
pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            Delete           Bound    redis/redis-data-redis-0   redis-nfs               7m6s

#  View the copied information , It can be seen that the synchronization is normal 
[[email protected] 1master-Nslave]# kubectl exec redis-3 -n redis -- redis-cli -a 123456 info replication
# Replication
role:slave
master_host:redis-0.redis.redis.svc.cluster.local
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:630
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:03c3dd18042139cbe116946f6c46c640fb91681b
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:630
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:449
repl_backlog_histlen:182
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.

Shrinkage capacity

Shrink volume from redis-N->redis-0

#  Shrinkage capacity 
[[email protected] 1master-Nslave]# kubectl scale statefulset redis --replicas=1 -n redis
statefulset.apps/redis scaled

#  see pod
[[email protected] 1master-Nslave]# kubectl get pods -n redis
NAME                                      READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-7f6758d967-l9b5p   1/1     Running   0          11m
redis-0                                   1/1     Running   0          11m


#  see pv,pvc, It can be seen that even if pod Been deleted pvc and pv Have not been deleted , Later, when we expand the capacity, the corresponding pod Will still use the previous pv,
[[email protected] 1master-Nslave]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                      STORAGECLASS   REASON   AGE
pvc-365be101-2ced-4800-9db0-be68fdedd64d   500Mi      RWX            Delete           Bound    redis/redis-data-redis-3   redis-nfs               6m29s
pvc-521d77ec-64df-44e1-8a49-22d032046b86   500Mi      RWX            Delete           Bound    redis/redis-data-redis-2   redis-nfs               6m34s
pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            Delete           Bound    redis/redis-data-redis-1   redis-nfs               11m
pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            Delete           Bound    redis/redis-data-redis-0   redis-nfs               12m
[[email protected] 1master-Nslave]# kubectl get pvc -n redis
NAME                 STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
redis-data-redis-0   Bound    pvc-e0642424-f6b3-405f-9d12-d53b277be042   500Mi      RWX            redis-nfs      12m
redis-data-redis-1   Bound    pvc-5925df68-31da-41c9-9655-7e9bd4c9bfb6   500Mi      RWX            redis-nfs      11m
redis-data-redis-2   Bound    pvc-521d77ec-64df-44e1-8a49-22d032046b86   500Mi      RWX            redis-nfs      6m39s
redis-data-redis-3   Bound    pvc-365be101-2ced-4800-9db0-be68fdedd64d   500Mi      RWX            redis-nfs      6m34s