# Find which member of the Stateful Set this pod is running
# e.g. "redis-cluster-0" -> "0"
PET_ORDINAL=$(cat /etc/podinfo/pod_name | rev | cut -d- -f1)
MY_SHARD=$(($PET_ORDINAL % $NUM_SHARDS))

redis-server /conf/redis.conf &

# TODO: Wait until redis-server process is ready
sleep 1

if [ $PET_ORDINAL -lt $NUM_SHARDS ]; then
# Set up primary nodes. Divide slots into equal(ish) contiguous blocks
NUM_SLOTS=$(( 16384 / $NUM_SHARDS ))
REMAINDER=$(( 16384 % $NUM_SHARDS ))
START_SLOT=$(( $NUM_SLOTS * $MY_SHARD + ($MY_SHARD < $REMAINDER ? $MY_SHARD : $REMAINDER) ))
END_SLOT=$(( $NUM_SLOTS * ($MY_SHARD+1) + ($MY_SHARD+1 < $REMAINDER ? $MY_SHARD+1 : $REMAINDER) - 1 ))

PEER_IP=$(perl -MSocket -e "print inet_ntoa(scalar(gethostbyname(\"redis-cluster-0.redis-cluster.$POD_NAMESPACE.svc.cluster.local\")))")
redis-cli --pass "xxxxxx" cluster meet $PEER_IP 6379
redis-cli --pass "xxxxxx"cluster addslots $(seq $START_SLOT $END_SLOT)
else
# Set up a replica
PEER_IP=$(perl -MSocket -e "print inet_ntoa(scalar(gethostbyname(\"redis-cluster-$MY_SHARD.redis-cluster.$POD_NAMESPACE.svc.cluster.local\")))")
redis-cli --pass "xxxxxx" --cluster add-node localhost:6379 $PEER_IP:6379 --cluster-slave
fi

wait
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: redis-cluster
spec:
podManagementPolicy: OrderedReady # default
serviceName: redis-cluster
replicas: 6
selector:
matchLabels:
app: redis-cluster # has to match .spec.template.metadata.labels
template:
metadata:
labels:
app: redis-cluster
name: redis-cluster
spec:
# affinity: # Ensure that each Redis instance is provisioned on a different k8s node
# podAntiAffinity:
# requiredDuringSchedulingIgnoredDuringExecution:
# - labelSelector:
# matchExpressions:
# - key: "app"
# operator: In
# values:
# - redis-cluster
# topologyKey: "kubernetes.io/hostname"
terminationGracePeriodSeconds: 10
containers:
- name: redis-cluster
image: redis:6.2.6
ports:
- containerPort: 6379
name: client
- containerPort: 16379
name: gossip
command:
- sh
args:
- /conf/bootstrap-pod.sh
# Ensure that Redis is online before initializing the next node.
# TODO: Test that the cluster node is init'd properly.
readinessProbe:
exec:
command:
- sh
- -c
- "redis-cli -h $(hostname) ping"
initialDelaySeconds: 5
timeoutSeconds: 5

securityContext:
capabilities:
add:
- IPC_LOCK
# Mark a node as down if Redis server stops running
livenessProbe:
exec:
command:
- sh
- -c
- "redis-cli -h $(hostname) ping"
initialDelaySeconds: 20
periodSeconds: 3
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: NUM_SHARDS
value: "3" # If you modify this value, make sure there are at least 2 times the number of replicas
volumeMounts:
- name: conf
mountPath: /conf
readOnly: false
- name: podinfo
mountPath: /etc/podinfo
readOnly: false
initContainers:
# Wait for the redis-cluster service to exist. We need it to resolve the hostnames of our nodes
- name: init-redis-cluster
image: busybox:1.28
command: ['sh', '-c', "until nslookup redis-cluster.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for redis-cluster; sleep 2; done"]
volumes:
# Insert our pre-baked Redis configuration file into /conf/redis.conf
- name: conf
configMap:
name: redis-cluster-config
items:
- key: redis.conf
path: redis.conf
- key: bootstrap-pod.sh # TODO: Move this or extract it into its own Docker image
path: bootstrap-pod.sh
# The init container will use this info to find cluster peers
- name: podinfo
downwardAPI:
items:
- path: "labels"
fieldRef:
fieldPath: metadata.labels
- path: "annotations"
fieldRef:
fieldPath: metadata.annotations
- path: "pod_name"
fieldRef:
fieldPath: metadata.name
- path: "pod_namespace"
fieldRef:
fieldPath: metadata.namespace

---REDISINSIGHT----

apiVersion: v1
kind: Service
metadata:
name: redisinsight-service # name should not be 'redisinsight'
# since the service creates
# environment variables that
# conflicts with redisinsight
# application's environment
# variables `RI_APP_HOST` and
# `RI_APP_PORT`
spec:
type: LoadBalancer
ports:
- port: 80
targetPort: 5540
selector:
app: redisinsight
---
# RedisInsight deployment with name 'redisinsight'
apiVersion: apps/v1
kind: Deployment
metadata:
name: redisinsight #deployment name
labels:
app: redisinsight #deployment label
spec:
replicas: 1 #a single replica pod
selector:
matchLabels:
app: redisinsight #which pods is the deployment managing, as defined by the pod template
template: #pod template
metadata:
labels:
app: redisinsight #label for pod/s
spec:
containers:

- name: redisinsight #Container name (DNS_LABEL, unique)
image: redis/redisinsight:latest #repo/image
imagePullPolicy: IfNotPresent #Installs the latest RedisInsight version
volumeMounts:
- name: redisinsight #Pod volumes to mount into the container's filesystem. Cannot be updated.
mountPath: /data
ports:
- containerPort: 5540 #exposed container port and protocol
protocol: TCP
volumes:
- name: redisinsight
emptyDir: {}

[root@k8s-ca-master2 k8s_HA_Centos7]# cat redis-fail.sh
#!/bin/bash
echo -n 0
/usr/bin/redis-cli -h redis-cluster -a xxxxxx cluster nodes | grep -E "(disconnected|fail|noaddr)" | wc -l

[root@k8s-ca-master2 k8s_HA_Centos7]# cat redis-nodes.sh
#!/bin/bash
echo -n 0
/usr/bin/redis-cli -h redis-cluster -a xxxxxx cluster nodes | wc -l

exec redis-nodes /bin/bash /etc/snmp/redis-nodes.sh
exec redis-fail /bin/bash /etc/snmp/redis-fail.sh