k8s部署redis cluster集群
k8s以StatefulSet方式部署redis cluster集群：
1. 部署nfs
2. 创建pv
3. 部署redis
4. 初始化redis集群
- 主机说明：
| 系统 | ip | 角色 | cpu | 内存 | hostname |
|---|---|---|---|---|---|
| CentOS 7.8 | 192.168.30.128 | master | >=2 | >=2G | master1 |
| CentOS 7.8 | 192.168.30.129 | master | >=2 | >=2G | master2 |
| CentOS 7.8 | 192.168.30.130 | node | >=2 | >=2G | node1 |
| CentOS 7.8 | 192.168.30.131 | node | >=2 | >=2G | node2 |
| CentOS 7.8 | 192.168.30.132 | node | >=2 | >=2G | node3 |
kubectl get node
NAME STATUS ROLES AGE VERSION
master1 Ready master 33d v1.14.0
master2 Ready master 33d v1.14.0
node1 Ready <none> 33d v1.14.0
node2 Ready <none> 33d v1.14.0
node3 Ready <none> 33d v1.14.0
部署nfs
在master2节点上做nfs共享，
yum -y install nfs-utils rpcbind
mkdir -p /data/redis/{cluster0,cluster1,cluster2,cluster3,cluster4,cluster5}
vim /etc/exports
/data/redis/cluster0 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster1 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster2 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster3 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster4 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster5 192.168.30.0/24(rw,sync,no_root_squash)
chmod -R 755 /data/redis
exportfs -arv
systemctl enable rpcbind && systemctl start rpcbind
systemctl enable nfs && systemctl start nfs
nfs部署完毕。对于需要使用nfs的node节点，都要安装nfs：
yum -y install nfs-utils
创建pv
- 创建pv：
mkdir -p /home/k8s/redis && cd /home/k8s/redis
vim pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv0
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster0
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv1
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster1
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv2
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster2
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv3
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster3
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv4
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster4
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv5
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster5
kubectl apply -f pv.yaml
kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv0 1Gi RWX Retain Available 3s
nfs-pv1 1Gi RWX Retain Available 3s
nfs-pv2 1Gi RWX Retain Available 3s
nfs-pv3 1Gi RWX Retain Available 3s
nfs-pv4 1Gi RWX Retain Available 3s
nfs-pv5 1Gi RWX Retain Available 3s
pv创建完毕。
部署redis
vim namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
name: public-service
vim redis.conf
appendonly yes
cluster-enabled yes
cluster-config-file /var/lib/redis/nodes.conf
cluster-node-timeout 5000
dir /var/lib/redis
port 6379
vim redis.yaml
apiVersion: v1
kind: Service
metadata:
name: redis
namespace: public-service
labels:
app: redis
spec:
selector:
app: redis
appCluster: redis-cluster
ports:
- name: redis
port: 6379
clusterIP: None
---
apiVersion: v1
kind: Service
metadata:
name: redis-access
namespace: public-service
labels:
app: redis
spec:
selector:
app: redis
appCluster: redis-cluster
ports:
- name: redis-access
protocol: TCP
port: 6379
targetPort: 6379
---
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
name: redis
namespace: public-service
spec:
serviceName: redis
replicas: 6
template:
metadata:
labels:
app: redis
appCluster: redis-cluster
spec:
terminationGracePeriodSeconds: 20
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: app
operator: In
values:
- redis
topologyKey: kubernetes.io/hostname
containers:
- name: redis
image: redis:latest
command:
- "redis-server"
args:
- "/etc/redis/redis.conf"
- "--protected-mode"
- "no"
resources:
requests:
cpu: "500m"
memory: "500Mi"
ports:
- containerPort: 6379
name: redis
protocol: TCP
- containerPort: 16379
name: cluster
protocol: TCP
volumeMounts:
- name: conf
mountPath: /etc/redis
- name: data
mountPath: /var/lib/redis
volumes:
- name: conf
configMap:
name: redis-conf
items:
- key: redis.conf
path: redis.conf
volumeClaimTemplates:
- metadata:
name: data
namespace: public-service
spec:
accessModes: [ "ReadWriteMany" ]
resources:
requests:
storage: 1Gi
kubectl apply -f namespace.yaml
kubectl create configmap redis-conf --from-file=redis.conf -n public-service
kubectl apply -f redis.yaml
kubectl get svc -n public-service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
redis ClusterIP None <none> 6379/TCP 20s
redis-access ClusterIP 10.96.2.100 <none> 6379/TCP 20s
kubectl get pod -n public-service
NAME READY STATUS RESTARTS AGE
redis-0 1/1 Running 0 2m43s
redis-1 1/1 Running 0 2m18s
redis-2 1/1 Running 0 108s
redis-3 1/1 Running 0 80s
redis-4 1/1 Running 0 48s
redis-5 1/1 Running 0 30s
kubectl get pvc -n public-service
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
data-redis-0 Bound nfs-pv4 1Gi RWX 3m4s
data-redis-1 Bound nfs-pv0 1Gi RWX 2m39s
data-redis-2 Bound nfs-pv1 1Gi RWX 2m9s
data-redis-3 Bound nfs-pv2 1Gi RWX 101s
data-redis-4 Bound nfs-pv3 1Gi RWX 69s
data-redis-5 Bound nfs-pv5 1Gi RWX 51s
redis-access这个service方便集群内访问redis集群，redis部署完毕。
初始化redis集群
使用Redis-tribe工具进行集群的初始化。
- 下载redis-tribe：
kubectl run -it ubuntu --image=ubuntu --restart=Never -n public-service bash
root@ubuntu:/# cat > /etc/apt/sources.list << EOF
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse
EOF
root@ubuntu:/# apt-get update
root@ubuntu:/# apt-get install -y libncursesw5 libreadline6 libtinfo5 --allow-remove-essential
root@ubuntu:/# apt-get install -y libpython2.7-stdlib python2.7 python-pip redis-tools dnsutils
root@ubuntu:/# pip install --upgrade pip
root@ubuntu:/# pip install redis-trib==0.5.1
- 初始化集群：
root@ubuntu:/# redis-trib.py create \
`dig +short redis-0.redis.public-service.svc.cluster.local`:6379 \
`dig +short redis-1.redis.public-service.svc.cluster.local`:6379 \
`dig +short redis-2.redis.public-service.svc.cluster.local`:6379
root@ubuntu:/# redis-trib.py replicate \
--master-addr `dig +short redis-0.redis.public-service.svc.cluster.local`:6379 \
--slave-addr `dig +short redis-3.redis.public-service.svc.cluster.local`:6379
root@ubuntu:/# redis-trib.py replicate \
--master-addr `dig +short redis-1.redis.public-service.svc.cluster.local`:6379 \
--slave-addr `dig +short redis-4.redis.public-service.svc.cluster.local`:6379
root@ubuntu:/# redis-trib.py replicate \
--master-addr `dig +short redis-2.redis.public-service.svc.cluster.local`:6379 \
--slave-addr `dig +short redis-5.redis.public-service.svc.cluster.local`:6379
root@ubuntu:/# exit
- 查看集群：
kubectl exec -it -n public-service redis-0 bash
root@redis-0:/data# redis-cli -c
127.0.0.1:6379> CLUSTER NODES #列出节点信息
aac2b3d320da67eedf3512ed0e38a1cdce5bc8fe 172.10.2.55:6379@16379 slave 7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 0 1592276224727 3 connected
2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 172.10.2.54:6379@16379 master - 0 1592276224224 1 connected 0-5461
524f03526a4b683d7d4de19296431810bfdc22cf 172.10.3.60:6379@16379 slave df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 0 1592276223117 5 connected
7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 172.10.4.77:6379@16379 myself,master - 0 1592276224000 2 connected 5462-10922
df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 172.10.3.59:6379@16379 master - 0 1592276223217 0 connected 10923-16383
c1dbaaef4a583e372c43eed52c22cd9ad7184d18 172.10.4.78:6379@16379 slave 2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 0 1592276223719 4 connected
127.0.0.1:6379> CLUSTER INFO #集群状态
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:5
cluster_my_epoch:2
cluster_stats_messages_ping_sent:514
cluster_stats_messages_pong_sent:491
cluster_stats_messages_meet_sent:2
cluster_stats_messages_sent:1007
cluster_stats_messages_ping_received:491
cluster_stats_messages_pong_received:516
cluster_stats_messages_received:1007
redis集群初始化完成，已经形成3主3从的cluster集群。
- 写入数据：
127.0.0.1:6379> SET key1 aaa
OK
127.0.0.1:6379> SET key2 bbb
-> Redirected to slot [4998] located at 172.10.2.54:6379
OK
172.10.2.54:6379> SET key3 ccc
OK
kubectl exec -it -n public-service redis-4 bash
root@redis-4:/data# redis-cli -c
127.0.0.1:6379> GET key1
-> Redirected to slot [9189] located at 172.10.4.77:6379
"aaa"
172.10.4.77:6379> GET key2
-> Redirected to slot [4998] located at 172.10.2.54:6379
"bbb"
172.10.2.54:6379> GET key3
"ccc"
可以看出redis cluster集群是去中心化的，每个节点都是平等的，连接哪个节点都可以获取和设置数据。
- 主从切换：
选择redis-2模拟宕掉，测试主从切换，
kubectl get pod -n public-service -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
redis-0 1/1 Running 0 62m 172.10.4.77 node1 <none> <none>
redis-1 1/1 Running 0 62m 172.10.2.54 node2 <none> <none>
redis-2 1/1 Running 0 61m 172.10.3.59 node3 <none> <none>
redis-3 1/1 Running 0 61m 172.10.2.55 node2 <none> <none>
redis-4 1/1 Running 0 61m 172.10.4.78 node1 <none> <none>
redis-5 1/1 Running 0 61m 172.10.3.60 node3 <none> <none>
ubuntu 0/1 Completed 0 57m 172.10.2.56 node2 <none> <none>
kubectl exec -it -n public-service redis-2 bash
root@redis-2:/data# redis-cli -c
127.0.0.1:6379> ROLE
1) "master"
2) (integer) 2898
3) 1) 1) "172.10.3.60"
2) "6379"
3) "2898"
可以看到，redis-2是master，它的slave是172.10.3.60，即redis-5。
kubectl delete pod -n public-service redis-2 #模拟节点宕掉
kubectl get pod -n public-service redis-2 -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
redis-2 1/1 Running 0 38s 172.10.3.61 node3 <none> <none>
kubectl exec -it -n public-service redis-2 bash
root@redis-2:/data# redis-cli -c
127.0.0.1:6379> ROLE
1) "slave"
2) "172.10.3.60"
3) (integer) 6379
4) "connected"
5) (integer) 3430
kubectl exec -it -n public-service redis-5 bash
root@redis-5:/data# redis-cli -c
127.0.0.1:6379> ROLE
1) "master"
2) (integer) 3584
3) 1) 1) "172.10.3.61"
2) "6379"
3) "3570"
127.0.0.1:6379> CLUSTER NODES
aac2b3d320da67eedf3512ed0e38a1cdce5bc8fe 172.10.2.55:6379@16379 slave 7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 0 1592278859530 2 connected
2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 172.10.2.54:6379@16379 master - 0 1592278859000 1 connected 0-5461
c1dbaaef4a583e372c43eed52c22cd9ad7184d18 172.10.4.78:6379@16379 slave 2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 0 1592278859000 1 connected
524f03526a4b683d7d4de19296431810bfdc22cf 172.10.3.60:6379@16379 myself,master - 0 1592278857000 6 connected 10923-16383
7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 172.10.4.77:6379@16379 master - 0 1592278858021 2 connected 5462-10922
df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 172.10.3.61:6379@16379 slave 524f03526a4b683d7d4de19296431810bfdc22cf 0 1592278859000 6 connected
可以看到，redis-2在重启之后变为slave，而它之前的slave——redis-5变为master，而且是新redis-2的master。
集群的主从切换没有问题。k8s部署redis cluster集群完成。