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This is an Enterprise-only feature. Please install
KubeDB Enterprise Edition to try this feature.
Run Redis with TLS/SSL (Transport Encryption)
KubeDB supports providing TLS/SSL encryption for Redis. This tutorial will show you how to use KubeDB to run a Redis database with TLS/SSL encryption.
Before You Begin
-
At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
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Install cert-manger v1.0.0 or later to your cluster to manage your SSL/TLS certificates.
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Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.
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To keep things isolated, this tutorial uses a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/redis folder in GitHub repository kubedb/docs.
Overview
KubeDB uses following crd fields to enable SSL/TLS encryption in Redis and RedisSentinel.
There are two basic things to keep in mind when securing Redis using TLS in Sentinel Mode.
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Either Sentinel instance and Redis database both should have TLS enabled or both have TLS disabled.
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If TLS enabled, both Sentinel instance and Redis database should use the same Issuer. If they are in different namespace, in order to use same issuer, the certificates should be signed using ClusterIssuer
Read about the fields in details in redis concept and redissentinel concept
Create Issuer/ ClusterIssuer
We are going to create an example ClusterIssuer that will be used throughout the duration of this tutorial to enable SSL/TLS in Redis. Alternatively, you can follow this cert-manager tutorial to create your own ClusterIssuer.
- Start off by generating you can certificate using openssl.
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=redis/O=kubedb"
- Now create a ca-secret using the certificate files you have just generated. The secret should be created in
cert-manager namespace to create the ClusterIssuer.
$ kubectl create secret tls redis-ca \
--cert=ca.crt \
--key=ca.key \
--namespace=cert-manager
Now, create an ClusterIssuer using the ca-secret you have just created. The YAML file looks like this:
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
name: redis-ca-issuer
spec:
ca:
secretName: redis-ca
Apply the YAML file:
$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/examples/redis/tls/clusterissuer.yaml
clusterissuer.cert-manager.io/redis-ca-issuer created
TLS/SSL encryption in Sentinel
Below is the YAML for Redis in Sentinel Mode.
apiVersion: kubedb.com/v1alpha2
kind: RedisSentinel
metadata:
name: sen-tls
namespace: demo
spec:
replicas: 3
version: "6.2.5"
tls:
issuerRef:
apiGroup: "cert-manager.io"
kind: ClusterIssuer
name: redis-ca-issuer
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
Deploy Redis in Sentinel Mode
$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/examples/redis/tls/sentinel-ssl.yaml
redissentinel.kubedb.com/sen-tls created
Now, wait until sen-tls has status Ready. i.e,
$ watch kubectl get redissentinel -n demo
Every 2.0s: kubectl get redis -n demo
NAME VERSION STATUS AGE
sen-tls 6.2.5 Ready 111s
Verify TLS/SSL in Redis in Sentinel Mode
Now, connect to this database by exec into a pod and verify if tls has been set up as intended.
$ kubectl describe secret -n demo sen-tls-client-cert
Name: sen-tls-client-cert
Namespace: demo
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=sen-tls
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=redissentinels.kubedb.com
Annotations: cert-manager.io/alt-names:
cert-manager.io/certificate-name: sen-tls-client-cert
cert-manager.io/common-name: default
cert-manager.io/ip-sans:
cert-manager.io/issuer-group: cert-manager.io
cert-manager.io/issuer-kind: ClusterIssuer
cert-manager.io/issuer-name: redis-ca-issuer
cert-manager.io/uri-sans:
Type: kubernetes.io/tls
Data
====
ca.crt: 1147 bytes
tls.crt: 1127 bytes
tls.key: 1675 bytes
Now, Lets exec into a redis container and find out the username to connect in a redis shell,
$ kubectl exec -it -n demo sen-tls-0 -c redissentinel -- bash
root@sen-tls-0:/data# ls /certs
ca.crt client.crt client.key server.crt server.key
root@sen-tls-0:/data# apt-get update; apt-get install openssl;
...
root@sen-tls-0:/data# openssl x509 -in /certs/ca.crt -inform PEM -subject -nameopt RFC2253 -noout
subject=O=kubedb,CN=redis
TLS/SSL encryption in Redis in Sentinel Mode
Below is the YAML for Redis in Sentinel Mode.
apiVersion: kubedb.com/v1alpha2
kind: Redis
metadata:
name: rd-tls
namespace: demo
spec:
version: "6.2.5"
mode: Sentinel
replicas: 3
sentinelRef:
name: sen-tls
namespace: demo
tls:
issuerRef:
apiGroup: "cert-manager.io"
kind: ClusterIssuer
name: redis-ca-issuer
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
Deploy Redis in Sentinel Mode
$ kubectl create -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/examples/redis/tls/rd-sentinel.yaml
redis.kubedb.com/rd-tls created
Now, wait until rd-tls has status Ready. i.e,
$ watch kubectl get rd -n demo
Every 2.0s: kubectl get redis -n demo
NAME VERSION STATUS AGE
rd-tls 6.2.5 Ready 2m14s
Verify TLS/SSL in Redis in Sentinel Mode
Now, connect to this database by exec into a pod and verify if tls has been set up as intended.
$ kubectl describe secret -n demo rd-tls-client-cert
Name: rd-tls-client-cert
Namespace: demo
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=rd-tls
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=redises.kubedb.com
Annotations: cert-manager.io/alt-names:
cert-manager.io/certificate-name: rd-tls-client-cert
cert-manager.io/common-name: default
cert-manager.io/ip-sans:
cert-manager.io/issuer-group: cert-manager.io
cert-manager.io/issuer-kind: ClusterIssuer
cert-manager.io/issuer-name: redis-ca-issuer
cert-manager.io/uri-sans:
Type: kubernetes.io/tls
Data
====
tls.key: 1679 bytes
ca.crt: 1147 bytes
tls.crt: 1127 bytes
Now, Lets exec into a redis container and find out the username to connect in a redis shell,
$ kubectl exec -it -n demo rd-tls-0 -c redis -- bash
root@rd-tls-0:/data# ls /certs
ca.crt client.crt client.key server.crt server.key
root@rd-tls-0:/data# apt-get update; apt-get install openssl;
...
root@rd-tls-0:/data# openssl x509 -in /certs/ca.crt -inform PEM -subject -nameopt RFC2253 -noout
subject=O=kubedb,CN=redis
Now, we can connect using CN=redis,O=kubedb as root to connect to the redis and write some data
$ kubectl exec -it -n demo rd-tls-0 -c redis -- bash
# Trying to connect without tls certificates
root@rd-tls-0:/data# redis-cli
127.0.0.1:6379>
127.0.0.1:6379> set hello world
# Can not write data
Error: Connection reset by peer
# Trying to connect with tls certificates
root@rd-tls-0:/data# redis-cli --tls --cert "/certs/client.crt" --key "/certs/client.key" --cacert "/certs/ca.crt"
127.0.0.1:6379>
127.0.0.1:6379> set hello world
OK
127.0.0.1:6379> exit
Cleaning up
To clean up the Kubernetes resources created by this tutorial, run:
$ kubectl patch -n demo redis/rd-tls -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
redis.kubedb.com/rd-tls patched
$ kubectl delete -n demo redis rd-tls
redis.kubedb.com "rd-tls" deleted
$ kubectl patch -n demo redissentinel/sen-tls -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
redissentinel.kubedb.com/sen-tls patched
$ kubectl delete -n demo redissentinel sen-tls
redissentinel.kubedb.com "sen-tls" deleted
$ kubectl delete clusterissuer redis-ca-issuer
clusterissuer.cert-manager.io "redis-ca-issuer" deleted
Next Steps
