Merge pull request #32 from marcel-dempers/redis-kubernetes

redis on kubernetes

storage/redis/kubernetes/readme.md

@@ -0,0 +1,56 @@
+# Redis on Kubernetes
+
+Create a cluster with [kind](https://kind.sigs.k8s.io/docs/user/quick-start/)
+
+```
+kind create cluster --name redis --image kindest/node:v1.18.4
+```
+
+## Namespace
+
+```
+kubectl create ns redis
+```
+
+## Storage Class
+
+```
+kubectl get storageclass
+NAME                 PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
+standard (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  84s
+```
+
+## Deployment: Redis nodes
+
+```
+cd storage/redis/kubernetes/
+kubectl apply -n redis -f ./redis/redis-configmap.yaml
+kubectl apply -n redis -f ./redis/redis-statefulset.yaml
+
+kubectl -n redis get pods
+kubectl -n redis get pv
+
+kubectl -n redis logs redis-0
+kubectl -n redis logs redis-1
+kubectl -n redis logs redis-2
+```
+
+## Test replication status
+
+```
+kubectl -n redis exec -it redis-0 sh
+redis-cli 
+auth a-very-complex-password-here
+info replication
+```
+
+## Deployment: Redis Sentinel (3 instances)
+
+```
+cd storage/redis/kubernetes/
+kubectl apply -n redis -f ./sentinel/sentinel-statefulset.yaml
+
+kubectl -n redis get pods
+kubectl -n redis get pv
+kubectl -n redis logs sentinel-0
+```

storage/redis/kubernetes/redis/redis-statefulset.yaml

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+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: redis
+spec:
+  serviceName: redis
+  replicas: 3
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      initContainers:
+      - name: config
+        image: redis:6.0-alpine
+        command: [ "sh", "-c" ]
+        args:
+          - |
+            cp /tmp/redis/redis.conf /etc/redis/redis.conf
+            
+            echo "finding master..."
+            if [ "$(redis-cli -h sentinel -p 5000 ping)" != "PONG" ]; then
+              echo "master not found, defaulting to redis-0"
+
+              if [ "$(hostname)" == "redis-0" ]; then
+                echo "this is redis-0, not updating config..."
+              else
+                echo "updating redis.conf..."
+                echo "slaveof redis-0.redis.redis.svc.cluster.local 6379" >> /etc/redis/redis.conf
+              fi
+            else
+              echo "sentinel found, finding master"
+              MASTER="$(redis-cli -h sentinel -p 5000 sentinel get-master-addr-by-name mymaster | grep -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}')"
+              echo "master found : $MASTER, updating redis.conf"
+              echo "slaveof $MASTER 6379" >> /etc/redis/redis.conf
+            fi
+        volumeMounts:
+        - name: redis-config
+          mountPath: /etc/redis/
+        - name: config
+          mountPath: /tmp/redis/
+      containers:
+      - name: redis
+        image: redis:6.0-alpine
+        command: ["redis-server"]
+        args: ["/etc/redis/redis.conf"]
+        ports:
+        - containerPort: 6379
+          name: redis
+        volumeMounts:
+        - name: data
+          mountPath: /data
+        - name: redis-config
+          mountPath: /etc/redis/
+      volumes:
+      - name: redis-config
+        emptyDir: {}
+      - name: config
+        configMap:
+          name: redis-config
+  volumeClaimTemplates:
+  - metadata:
+      name: data
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      storageClassName: "standard"
+      resources:
+        requests:
+          storage: 50Mi
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: redis
+spec:
+  clusterIP: None
+  ports:
+  - port: 6379
+    targetPort: 6379
+    name: redis
+  selector:
+    app: redis

storage/redis/kubernetes/sentinel/sentinel-statefulset.yaml

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+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: sentinel
+spec:
+  serviceName: sentinel
+  replicas: 3
+  selector:
+    matchLabels:
+      app: sentinel
+  template:
+    metadata:
+      labels:
+        app: sentinel
+    spec:
+      initContainers:
+      - name: config
+        image: redis:6.0-alpine
+        command: [ "sh", "-c" ]
+        args:
+          - |
+            REDIS_PASSWORD=a-very-complex-password-here
+            nodes=redis-0.redis.redis.svc.cluster.local,redis-1.redis.redis.svc.cluster.local,redis-2.redis.redis.svc.cluster.local
+
+            for i in ${nodes//,/ }
+            do
+                echo "finding master at $i"
+                MASTER=$(redis-cli --no-auth-warning --raw -h $i -a $REDIS_PASSWORD info replication | awk '{print $1}' | grep master_host: | cut -d ":" -f2)
+                if [ "$MASTER" == "" ]; then
+                    echo "no master found"
+                    MASTER=
+                else
+                    echo "found $MASTER"
+                    break
+                fi
+            done
+            echo "sentinel monitor mymaster $MASTER 6379 2" >> /tmp/master
+
+            echo "port 5000
+            $(cat /tmp/master)
+            sentinel down-after-milliseconds mymaster 5000
+            sentinel failover-timeout mymaster 60000
+            sentinel parallel-syncs mymaster 1
+            sentinel auth-pass mymaster $REDIS_PASSWORD
+            " > /etc/redis/sentinel.conf
+            cat /etc/redis/sentinel.conf
+        volumeMounts:
+        - name: redis-config
+          mountPath: /etc/redis/
+      containers:
+      - name: sentinel
+        image: redis:6.0-alpine
+        command: ["redis-sentinel"]
+        args: ["/etc/redis/sentinel.conf"]
+        ports:
+        - containerPort: 5000
+          name: sentinel
+        volumeMounts:
+        - name: redis-config
+          mountPath: /etc/redis/
+        - name: data
+          mountPath: /data
+      volumes:
+      - name: redis-config
+        emptyDir: {}
+  volumeClaimTemplates:
+  - metadata:
+      name: data
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      storageClassName: "standard"
+      resources:
+        requests:
+          storage: 50Mi
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: sentinel
+spec:
+  clusterIP: None
+  ports:
+  - port: 5000
+    targetPort: 5000
+    name: sentinel
+  selector:
+    app: sentinel