Add Persistence to Redis pods

Makefile

@@ -1,4 +1,4 @@
-VERSION := 0.3.0
+VERSION := 0.4.0
 
 # Name of this service/application
 SERVICE_NAME := redis-operator
@@ -144,6 +144,6 @@ endif
 
 # Generate kubernetes code for types..
 .PHONY: update-codegen
-update-codegen: build
+update-codegen: docker-build
 	@echo ">> Generating code for Kubernetes CRD types..."
 	docker run --rm -v $(PWD):/go/src/github.com/spotahome/redis-operator/ $(REPOSITORY)-dev /bin/bash -c '$(UPDATE_CODEGEN_CMD)'

README.md

@@ -36,9 +36,9 @@ helm install --name redisfailover charts/redisoperator
 ## Usage
 Once the operator is deployed inside a Kubernetes cluster, a new API will be accesible, so you'll be able to create, update and delete redisfailovers.
 
-In order to deploy a new redis-failover a [specification](example/redisfailover.yaml) has to be created:
+In order to deploy a new redis-failover a [specification](example/redisfailover/all-options.yaml) has to be created:
 ```
-kubectl create -f https://raw.githubusercontent.com/spotahome/redis-operator/master/example/redisfailover.yaml
+kubectl create -f https://raw.githubusercontent.com/spotahome/redis-operator/master/redisfailover/all-options.yaml
 ```
 
 This redis-failover will be managed by the operator, resulting in the following elements created inside Kubernetes:
@@ -51,6 +51,13 @@ This redis-failover will be managed by the operator, resulting in the following
 
 **NOTE**: `NAME` is the named provided when creating the RedisFailover.
 
+### Persistance
+The operator has the ability of add persistance to Redis data. By default an `emptyDir` will be used, so the data is not saved.
+
+In order to have persistance, a PersistentVolumeClaim usage is allowed. The full [PVC definition has to be added](example/redisfailover/persistant-storage.yaml) to the Redis Failover Spec under the `Storage` section.
+
+**IMPORTANT**: By default, the persistent volume claims will be deleted when the Redis Failover is. If this is not the expected usage, a `keepAfterDeletion` flag can be added under the `storage` section of Redis. [An example is given](example/redisfailover/persistant-storage-no-pvc-deletion.yaml).
+
 ### Connection
 In order to connect to the redis-failover and use it, a [Sentinel-ready](https://redis.io/topics/sentinel-clients) library has to be used. This will connect through the Sentinel service to the Redis node working as a master.
 The connection parameters are the following:

api/redisfailover/v1alpha2/types.go

@@ -43,7 +43,7 @@ type RedisSettings struct {
 	Image           string                 `json:"image,omitempty"`
 	Version         string                 `json:"version,omitempty"`
 	ConfigMap       string                 `json:"configMap,omitempty"`
-	DataVolume      corev1.Volume          `json:"dataVolume,omitempty"`
+	Storage         RedisStorage           `json:"storage,omitempty"`
 }
 
 // SentinelSettings defines the specification of the sentinel cluster
@@ -65,6 +65,13 @@ type CPUAndMem struct {
 	Memory string `json:"memory"`
 }
 
+// RedisStorage defines the structure used to store the Redis Data
+type RedisStorage struct {
+	KeepAfterDeletion     bool                          `json:"keepAfterDeletion,omitempty"`
+	EmptyDir              *corev1.EmptyDirVolumeSource  `json:"emptyDir,omitempty"`
+	PersistentVolumeClaim *corev1.PersistentVolumeClaim `json:"persistentVolumeClaim,omitempty"`
+}
+
 // RedisFailoverStatus has the status of the cluster
 type RedisFailoverStatus struct {
 	Phase      Phase       `json:"phase"`

example/redisfailover.yaml → example/redisfailover/all-options.yaml

@@ -25,6 +25,6 @@ spec:
     exporter: false                          # Optional. False by default. Adds a redis-exporter container to export metrics.
     exporterImage: oliver006/redis_exporter  # Optional. oliver006/redis_exporter by default.
     exporterVersion: v0.11.3                 # Optional. v0.11.3 by default.
-    dataVolume:
-      name: redis-data
-      emptyDir: {}
+    storage:
+      emptyDir: {}                           # Optional. emptyDir by default.
+

example/redisfailover/persistant-storage-no-pvc-deletion.yaml

@@ -0,0 +1,21 @@
+apiVersion: storage.spotahome.com/v1alpha2
+kind: RedisFailover
+metadata:
+  name: redisfailover-persistant-keep
+spec:
+  sentinel:
+    replicas: 3
+  redis:
+    replicas: 3
+    storage:
+      keepAfterDeletion: true
+      persistentVolumeClaim:                           
+        metadata:
+          name: redisfailover-persistant-keep-data
+        spec:
+          accessModes:
+          - ReadWriteOnce
+          resources:
+            requests:
+              storage: 1Gi
+

example/redisfailover/persistant-storage.yaml

@@ -0,0 +1,20 @@
+apiVersion: storage.spotahome.com/v1alpha2
+kind: RedisFailover
+metadata:
+  name: redisfailover-persistant
+spec:
+  sentinel:
+    replicas: 3
+  redis:
+    replicas: 3
+    storage:
+      persistentVolumeClaim:                           
+        metadata:
+          name: redisfailover-persistant-data
+        spec:
+          accessModes:
+          - ReadWriteOnce
+          resources:
+            requests:
+              storage: 1Gi
+

operator/redisfailover/service/generator.go

@@ -14,6 +14,11 @@ import (
 	"github.com/spotahome/redis-operator/operator/redisfailover/util"
 )
 
+const (
+	redisConfigurationVolumeName = "redis-config"
+	redisStorageVolumeName       = "redis-data"
+)
+
 func generateSentinelService(rf *redisfailoverv1alpha2.RedisFailover, labels map[string]string, ownerRefs []metav1.OwnerReference) *corev1.Service {
 	name := GetSentinelName(rf)
 	namespace := rf.Namespace
@@ -205,6 +210,16 @@ func generateRedisStatefulSet(rf *redisfailoverv1alpha2.RedisFailover, labels ma
 		},
 	}
 
+	if rf.Spec.Redis.Storage.PersistentVolumeClaim != nil {
+		if !rf.Spec.Redis.Storage.KeepAfterDeletion {
+			// Set an owner reference so the persistent volumes are deleted when the RF is
+			rf.Spec.Redis.Storage.PersistentVolumeClaim.OwnerReferences = ownerRefs
+		}
+		ss.Spec.VolumeClaimTemplates = []corev1.PersistentVolumeClaim{
+			*rf.Spec.Redis.Storage.PersistentVolumeClaim,
+		}
+	}
+
 	if rf.Spec.Redis.Exporter {
 		exporter := createRedisExporterContainer(rf)
 		ss.Spec.Template.Spec.Containers = append(ss.Spec.Template.Spec.Containers, exporter)
@@ -523,17 +538,13 @@ func getRedisExporterImage(rf *redisfailoverv1alpha2.RedisFailover) string {
 func getRedisVolumeMounts(rf *redisfailoverv1alpha2.RedisFailover) []corev1.VolumeMount {
 	volumeMounts := []corev1.VolumeMount{
 		{
-			Name:      "redis-config",
+			Name:      redisConfigurationVolumeName,
 			MountPath: "/redis",
 		},
-	}
-
-	// check if data volume is set, if set, mount to /data
-	if rf.Spec.Redis.DataVolume.Name != "" {
-		volumeMounts = append(volumeMounts, corev1.VolumeMount{
-			Name:      rf.Spec.Redis.DataVolume.Name,
+		{
+			Name:      getRedisDataVolumeName(rf),
 			MountPath: "/data",
-		})
+		},
 	}
 
 	return volumeMounts
@@ -544,7 +555,7 @@ func getRedisVolumes(rf *redisfailoverv1alpha2.RedisFailover) []corev1.Volume {
 
 	volumes := []corev1.Volume{
 		{
-			Name: "redis-config",
+			Name: redisConfigurationVolumeName,
 			VolumeSource: corev1.VolumeSource{
 				ConfigMap: &corev1.ConfigMapVolumeSource{
 					LocalObjectReference: corev1.LocalObjectReference{
@@ -555,10 +566,44 @@ func getRedisVolumes(rf *redisfailoverv1alpha2.RedisFailover) []corev1.Volume {
 		},
 	}
 
-	// check if data volume is set, if not set skip it
-	if rf.Spec.Redis.DataVolume.Name != "" {
-		volumes = append(volumes, rf.Spec.Redis.DataVolume)
+	dataVolume := getRedisDataVolume(rf)
+	if dataVolume != nil {
+		volumes = append(volumes, *dataVolume)
 	}
 
 	return volumes
 }
+
+func getRedisDataVolume(rf *redisfailoverv1alpha2.RedisFailover) *corev1.Volume {
+	// This will find the volumed desired by the user. If no volume defined
+	// an EmptyDir will be used by default
+	switch {
+	case rf.Spec.Redis.Storage.PersistentVolumeClaim != nil:
+		return nil
+	case rf.Spec.Redis.Storage.EmptyDir != nil:
+		return &corev1.Volume{
+			Name: redisStorageVolumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: rf.Spec.Redis.Storage.EmptyDir,
+			},
+		}
+	default:
+		return &corev1.Volume{
+			Name: redisStorageVolumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: &corev1.EmptyDirVolumeSource{},
+			},
+		}
+	}
+}
+
+func getRedisDataVolumeName(rf *redisfailoverv1alpha2.RedisFailover) string {
+	switch {
+	case rf.Spec.Redis.Storage.PersistentVolumeClaim != nil:
+		return rf.Spec.Redis.Storage.PersistentVolumeClaim.Name
+	case rf.Spec.Redis.Storage.EmptyDir != nil:
+		return redisStorageVolumeName
+	default:
+		return redisStorageVolumeName
+	}
+}