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Reconfigure ZooKeeper TLS/SSL (Transport Encryption)

KubeDB supports reconfigure i.e. add, remove, update and rotation of TLS/SSL certificates for existing ZooKeeper database via a ZooKeeperOpsRequest. This tutorial will show you how to use KubeDB to reconfigure 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.

  • Install cert-manger v1.0.0 or later to your cluster to manage your SSL/TLS certificates.

  • Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.

  • 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/zookeeper folder in GitHub repository kubedb/docs.

Add TLS to a ZooKeeper database

Here, We are going to create a ZooKeeper without TLS and then reconfigure the database to use TLS.

Deploy ZooKeeper without TLS

In this section, we are going to deploy a ZooKeeper ensemble without TLS. In the next few sections we will reconfigure TLS using ZooKeeperOpsRequest CRD. Below is the YAML of the ZooKeeper CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: ZooKeeper
metadata:
  name: zk-quickstart
  namespace: demo
spec:
  version: "3.8.3"
  adminServerPort: 8080
  replicas: 3
  storage:
    resources:
      requests:
        storage: "1Gi"
    accessModes:
      - ReadWriteOnce
  deletionPolicy: "WipeOut"

Let’s create the ZooKeeper CR we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zookeeper.yaml
zookeeper.kubedb.com/zk-quickstart created

Now, wait until zk-quickstart has status Ready. i.e,

$ watch kubectl get zookeeper -n demo
NAME              TYPE                    VERSION   STATUS    AGE
zk-quickstart     kubedb.com/v1alpha2     3.8.3     Ready     60s

Now, we can exec one zookeeper broker pod and verify configuration that the TLS is disabled.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ cat ../conf/zoo.cfg
4lw.commands.whitelist=*
dataDir=/data
tickTime=2000
initLimit=10
syncLimit=2
clientPort=2181
globalOutstandingLimit=1000
preAllocSize=65536
snapCount=10000
commitLogCount=500
snapSizeLimitInKb=4194304
maxCnxns=0
maxClientCnxns=60
minSessionTimeout=4000
maxSessionTimeout=40000
autopurge.snapRetainCount=3
autopurge.purgeInterval=1
quorumListenOnAllIPs=false
admin.serverPort=8080
authProvider.1=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
reconfigEnabled=true
standaloneEnabled=false
dynamicConfigFile=/data/zoo.cfg.dynamic
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ 

We can verify from the above output that TLS is disabled for this Ensemble.

Create Issuer/ ClusterIssuer

Now, We are going to create an example Issuer that will be used to enable SSL/TLS in ZooKeeper. Alternatively, you can follow this cert-manager tutorial to create your own Issuer.

  • Start off by generating a ca certificates using openssl.
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=ca/O=kubedb"
Generating a RSA private key
................+++++
........................+++++
writing new private key to './ca.key'
-----
  • Now we are going to create a ca-secret using the certificate files that we have just generated.
$ kubectl create secret tls zookeeper-ca \
     --cert=ca.crt \
     --key=ca.key \
     --namespace=demo
secret/zookeeper-ca created

Now, Let’s create an Issuer using the zookeeper-ca secret that we have just created. The YAML file looks like this:

apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
  name: zk-issuer
  namespace: demo
spec:
  ca:
    secretName: zookeeper-ca

Let’s apply the YAML file:

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zookeeper-issuer.yaml
issuer.cert-manager.io/zk-issuer created

Create ZooKeeperOpsRequest

In order to add TLS to the zookeeper, we have to create a ZooKeeperOpsRequest CRO with our created issuer. Below is the YAML of the ZooKeeperOpsRequest CRO that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: ZooKeeperOpsRequest
metadata:
  name: zkops-add-tls
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: zk-quickstart
  tls:
    issuerRef:
      name: zookeeper-ca-issuer
      kind: Issuer
      apiGroup: "cert-manager.io"
    certificates:
      - alias: client
        subject:
          organizations:
            - zookeeper
          organizationalUnits:
            - client
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are performing reconfigure TLS operation on zk-quickstart cluster.
  • spec.type specifies that we are performing ReconfigureTLS on zookeeper.
  • spec.tls.issuerRef specifies the issuer name, kind and api group.
  • spec.tls.certificates specifies the certificates. You can learn more about this field from here.

Let’s create the ZooKeeperOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zookeeper-add-tls.yaml
zookeeperopsrequest.ops.kubedb.com/zkops-add-tls created

Verify TLS Enabled Successfully

Let’s wait for ZooKeeperOpsRequest to be Successful. Run the following command to watch ZooKeeperOpsRequest CRO,

$ kubectl get zookeeperopsrequest -n demo
NAME            TYPE             STATUS       AGE
zkops-add-tls   ReconfigureTLS   Successful   4m36s

We can see from the above output that the ZooKeeperOpsRequest has succeeded. If we describe the ZooKeeperOpsRequest we will get an overview of the steps that were followed.

$ kubectl describe zookeeperopsrequest -n demo zkops-add-tls 
Name:         zkops-add-tls
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ZooKeeperOpsRequest
Metadata:
  Creation Timestamp:  2024-11-04T05:46:18Z
  Generation:          1
  Resource Version:    2118117
  UID:                 aa25e2b8-2583-4757-b3f7-b053fc21819f
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  zk-quickstart
  Tls:
    Issuer Ref:
      API Group:  cert-manager.io
      Kind:       Issuer
      Name:       zookeeper-ca-issuer
  Type:           ReconfigureTLS
Status:
  Conditions:
    Last Transition Time:  2024-11-04T05:46:18Z
    Message:               ZooKeeper ops-request has started to reconfigure tls for zookeeper nodes
    Observed Generation:   1
    Reason:                ReconfigureTLS
    Status:                True
    Type:                  ReconfigureTLS
    Last Transition Time:  2024-11-04T05:46:31Z
    Message:               Successfully synced all certificates
    Observed Generation:   1
    Reason:                CertificateSynced
    Status:                True
    Type:                  CertificateSynced
    Last Transition Time:  2024-11-04T05:46:26Z
    Message:               get certificate; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetCertificate
    Last Transition Time:  2024-11-04T05:46:26Z
    Message:               check ready condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CheckReadyCondition
    Last Transition Time:  2024-11-04T05:46:26Z
    Message:               issuing condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  IssuingCondition
    Last Transition Time:  2024-11-04T05:46:36Z
    Message:               successfully reconciled the ZooKeeper with tls configuration
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-11-04T05:48:56Z
    Message:               Successfully restarted all nodes
    Observed Generation:   1
    Reason:                RestartNodes
    Status:                True
    Type:                  RestartNodes
    Last Transition Time:  2024-11-04T05:46:41Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T05:46:41Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T05:46:46Z
    Message:               running pod; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningPod
    Last Transition Time:  2024-11-04T05:47:26Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T05:47:26Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T05:48:16Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T05:48:16Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T05:48:56Z
    Message:               Successfully completed reconfigureTLS for zookeeper.
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:                    <none>

Now, Let’s exec into a zookeeper ensemble pod and verify the configuration that the TLS is enabled.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ cat ../conf/zoo.cfg
4lw.commands.whitelist=*
dataDir=/data
tickTime=2000
initLimit=10
syncLimit=2
clientPort=2181
globalOutstandingLimit=1000
preAllocSize=65536
snapCount=10000
commitLogCount=500
snapSizeLimitInKb=4194304
maxCnxns=0
maxClientCnxns=60
minSessionTimeout=4000
maxSessionTimeout=40000
autopurge.snapRetainCount=3
autopurge.purgeInterval=1
quorumListenOnAllIPs=false
admin.serverPort=8080
authProvider.1=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
reconfigEnabled=true
standaloneEnabled=false
dynamicConfigFile=/data/zoo.cfg.dynamic
secureClientPort=2182
serverCnxnFactory=org.apache.zookeeper.server.NettyServerCnxnFactory
authProvider.x509=org.apache.zookeeper.server.auth.X509AuthenticationProvider
ssl.keyStore.location=/var/private/ssl/server.keystore.jks
ssl.keyStore.password=fdjk2dgffqn9
ssl.trustStore.location=/var/private/ssl/server.truststore.jks
ssl.trustStore.password=fdjk2dgffqn9
sslQuorum=true
ssl.quorum.keyStore.location=/var/private/ssl/server.keystore.jks
ssl.quorum.keyStore.password=fdjk2dgffqn9
ssl.quorum.trustStore.location=/var/private/ssl/server.truststore.jks
ssl.quorum.trustStore.password=fdjk2dgffqn9
ssl.quorum.hostnameVerification=false
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ 

We can see from the above output that, keystore location is /var/private/ssl/server.keystore.jks which means that TLS is enabled.

Rotate Certificate

Now we are going to rotate the certificate of this cluster. First let’s check the current expiration date of the certificate.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ openssl x509 -in /var/private/ssl/tls.crt -inform PEM -enddate -nameopt RFC2253 -noout
notAfter=Feb  2 12:53:30 2025 GMT

So, the certificate will expire on this time Feb 2 12:53:30 2025 GMT.

Create ZooKeeperOpsRequest

Now we are going to increase it using a ZooKeeperOpsRequest. Below is the yaml of the ops request that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: ZooKeeperOpsRequest
metadata:
  name: zkops-rotate
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: zk-quickstart
  tls:
    rotateCertificates: true

Here,

  • spec.databaseRef.name specifies that we are performing reconfigure TLS operation on zk-quickstart.
  • spec.type specifies that we are performing ReconfigureTLS on our cluster.
  • spec.tls.rotateCertificates specifies that we want to rotate the certificate of this zookeeper cluster.

Let’s create the ZooKeeperOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zkops-rotate.yaml
zookeeperopsrequest.ops.kubedb.com/zkops-rotate created

Verify Certificate Rotated Successfully

Let’s wait for ZooKeeperOpsRequest to be Successful. Run the following command to watch ZooKeeperOpsRequest CRO,

$ kubectl get zookeeperopsrequests -n demo zkops-rotate
NAME            TYPE             STATUS       AGE
zkops-rotate    ReconfigureTLS   Successful   4m4s

We can see from the above output that the ZooKeeperOpsRequest has succeeded. If we describe the ZooKeeperOpsRequest we will get an overview of the steps that were followed.

$ kubectl describe zookeeperopsrequest -n demo zkops-rotate
Name:         zkops-rotate
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ZooKeeperOpsRequest
Metadata:
  Creation Timestamp:  2024-11-04T13:10:03Z
  Generation:          1
  Resource Version:    2153555
  UID:                 a1886cd3-784b-4523-936c-a510327d6129
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  zk-quickstart
  Tls:
    Rotate Certificates:  true
  Type:                   ReconfigureTLS
Status:
  Conditions:
    Last Transition Time:  2024-11-04T13:10:03Z
    Message:               ZooKeeper ops-request has started to reconfigure tls for zookeeper nodes
    Observed Generation:   1
    Reason:                ReconfigureTLS
    Status:                True
    Type:                  ReconfigureTLS
    Last Transition Time:  2024-11-04T13:10:16Z
    Message:               Successfully synced all certificates
    Observed Generation:   1
    Reason:                CertificateSynced
    Status:                True
    Type:                  CertificateSynced
    Last Transition Time:  2024-11-04T13:10:11Z
    Message:               get certificate; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetCertificate
    Last Transition Time:  2024-11-04T13:10:11Z
    Message:               check ready condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CheckReadyCondition
    Last Transition Time:  2024-11-04T13:10:11Z
    Message:               issuing condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  IssuingCondition
    Last Transition Time:  2024-11-04T13:10:22Z
    Message:               successfully reconciled the ZooKeeper with tls configuration
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-11-04T13:12:42Z
    Message:               Successfully restarted all nodes
    Observed Generation:   1
    Reason:                RestartNodes
    Status:                True
    Type:                  RestartNodes
    Last Transition Time:  2024-11-04T13:10:27Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:10:27Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:10:32Z
    Message:               running pod; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningPod
    Last Transition Time:  2024-11-04T13:11:07Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:11:07Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:11:52Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:11:52Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:12:42Z
    Message:               Successfully completed reconfigureTLS for zookeeper.
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                    Age    From                         Message
  ----     ------                                                    ----   ----                         -------
  Normal   Starting                                                  2m57s  KubeDB Ops-manager Operator  Start processing for ZooKeeperOpsRequest: demo/zkops-rotate
  Normal   Starting                                                  2m57s  KubeDB Ops-manager Operator  Pausing ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                2m57s  KubeDB Ops-manager Operator  Successfully paused ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: zkops-rotate
  Warning  get certificate; ConditionStatus:True                     2m49s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m49s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m49s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Warning  get certificate; ConditionStatus:True                     2m49s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m49s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m49s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Normal   CertificateSynced                                         2m49s  KubeDB Ops-manager Operator  Successfully synced all certificates
  Warning  get certificate; ConditionStatus:True                     2m44s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m44s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m44s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Warning  get certificate; ConditionStatus:True                     2m44s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m44s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m44s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Normal   CertificateSynced                                         2m44s  KubeDB Ops-manager Operator  Successfully synced all certificates
  Normal   UpdatePetSets                                             2m38s  KubeDB Ops-manager Operator  successfully reconciled the ZooKeeper with tls configuration
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-0    2m33s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-0  2m33s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  running pod; ConditionStatus:False                        2m28s  KubeDB Ops-manager Operator  running pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-1    113s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-1  113s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-2    68s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-2
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-2  68s    KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-2
  Normal   RestartNodes                                              18s    KubeDB Ops-manager Operator  Successfully restarted all nodes
  Normal   Starting                                                  18s    KubeDB Ops-manager Operator  Resuming ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                18s    KubeDB Ops-manager Operator  Successfully resumed ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: zkops-rotate

Now, let’s check the expiration date of the certificate.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ openssl x509 -in /var/private/ssl/tls.crt -inform PEM -enddate -nameopt RFC2253 -noout
notAfter=Feb 2 13:12:42 2025 GMT

As we can see from the above output, the certificate has been rotated successfully.

Change Issuer/ClusterIssuer

Now, we are going to change the issuer of this database.

  • Let’s create a new ca certificate and key using a different subject CN=ca-update,O=kubedb-updated.
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=ca-updated/O=kubedb-updated"
Generating a RSA private key
..............................................................+++++
......................................................................................+++++
writing new private key to './ca.key'
-----
  • Now we are going to create a new ca-secret using the certificate files that we have just generated.
$ kubectl create secret tls zookeeper-new-ca \
     --cert=ca.crt \
     --key=ca.key \
     --namespace=demo
secret/zookeeper-new-ca created

Now, Let’s create a new Issuer using the mongo-new-ca secret that we have just created. The YAML file looks like this:

apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
  name: zk-new-issuer
  namespace: demo
spec:
  ca:
    secretName: zookeeper-new-ca

Let’s apply the YAML file:

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zookeeper-new-issuer.yaml
issuer.cert-manager.io/zk-new-issuer created

Create ZooKeeperOpsRequest

In order to use the new issuer to issue new certificates, we have to create a ZooKeeperOpsRequest CRO with the newly created issuer. Below is the YAML of the ZooKeeperOpsRequest CRO that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: ZooKeeperOpsRequest
metadata:
  name: zkops-update-issuer
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: zk-quickstart
  tls:
    issuerRef:
      name: zk-new-issuer
      kind: Issuer
      apiGroup: "cert-manager.io"

Here,

  • spec.databaseRef.name specifies that we are performing reconfigure TLS operation on zk-quickstart cluster.
  • spec.type specifies that we are performing ReconfigureTLS on our zookeeper.
  • spec.tls.issuerRef specifies the issuer name, kind and api group.

Let’s create the ZooKeeperOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zookeeper-update-tls-issuer.yaml
zookeeperpsrequest.ops.kubedb.com/zkops-update-issuer created

Verify Issuer is changed successfully

Let’s wait for ZooKeeperOpsRequest to be Successful. Run the following command to watch ZooKeeperOpsRequest CRO,

$ kubectl get zookeeperopsrequests -n demo zkops-update-issuer
NAME                  TYPE             STATUS       AGE
zkops-update-issuer   ReconfigureTLS   Successful   8m6s

We can see from the above output that the ZooKeeperOpsRequest has succeeded. If we describe the ZooKeeperOpsRequest we will get an overview of the steps that were followed.

$ kubectl describe zookeeperopsrequest -n demo zkops-update-issuer
Name:         zkops-update-issuer
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ZooKeeperOpsRequest
Metadata:
  Creation Timestamp:  2024-11-04T13:27:25Z
  Generation:          1
  Resource Version:    2155331
  UID:                 399cae54-a6ab-4848-93ff-5dba09a128d7
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  zk-quickstart
  Tls:
    Issuer Ref:
      API Group:  cert-manager.io
      Kind:       Issuer
      Name:       zk-new-issuer
  Type:           ReconfigureTLS
Status:
  Conditions:
    Last Transition Time:  2024-11-04T13:27:25Z
    Message:               ZooKeeper ops-request has started to reconfigure tls for zookeeper nodes
    Observed Generation:   1
    Reason:                ReconfigureTLS
    Status:                True
    Type:                  ReconfigureTLS
    Last Transition Time:  2024-11-04T13:27:35Z
    Message:               Successfully synced all certificates
    Observed Generation:   1
    Reason:                CertificateSynced
    Status:                True
    Type:                  CertificateSynced
    Last Transition Time:  2024-11-04T13:27:30Z
    Message:               get certificate; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  GetCertificate
    Last Transition Time:  2024-11-04T13:27:30Z
    Message:               check ready condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  CheckReadyCondition
    Last Transition Time:  2024-11-04T13:27:30Z
    Message:               issuing condition; ConditionStatus:True
    Observed Generation:   1
    Status:                True
    Type:                  IssuingCondition
    Last Transition Time:  2024-11-04T13:27:40Z
    Message:               successfully reconciled the ZooKeeper with tls configuration
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-11-04T13:30:00Z
    Message:               Successfully restarted all nodes
    Observed Generation:   1
    Reason:                RestartNodes
    Status:                True
    Type:                  RestartNodes
    Last Transition Time:  2024-11-04T13:27:45Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:27:45Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:27:50Z
    Message:               running pod; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningPod
    Last Transition Time:  2024-11-04T13:28:30Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:28:30Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:29:20Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:29:20Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:30:00Z
    Message:               Successfully completed reconfigureTLS for zookeeper.
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                    Age    From                         Message
  ----     ------                                                    ----   ----                         -------
  Normal   Starting                                                  2m53s  KubeDB Ops-manager Operator  Start processing for ZooKeeperOpsRequest: demo/zkops-update-issuer
  Warning  get certificate; ConditionStatus:True                     2m48s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m48s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m48s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Warning  get certificate; ConditionStatus:True                     2m48s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m48s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m48s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Normal   CertificateSynced                                         2m48s  KubeDB Ops-manager Operator  Successfully synced all certificates
  Warning  get certificate; ConditionStatus:True                     2m43s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m43s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m43s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Warning  get certificate; ConditionStatus:True                     2m43s  KubeDB Ops-manager Operator  get certificate; ConditionStatus:True
  Warning  check ready condition; ConditionStatus:True               2m43s  KubeDB Ops-manager Operator  check ready condition; ConditionStatus:True
  Warning  issuing condition; ConditionStatus:True                   2m43s  KubeDB Ops-manager Operator  issuing condition; ConditionStatus:True
  Normal   CertificateSynced                                         2m43s  KubeDB Ops-manager Operator  Successfully synced all certificates
  Normal   UpdatePetSets                                             2m38s  KubeDB Ops-manager Operator  successfully reconciled the ZooKeeper with tls configuration
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-0    2m33s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-0  2m33s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  running pod; ConditionStatus:False                        2m28s  KubeDB Ops-manager Operator  running pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-1    108s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-1  108s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-2    58s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-2
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-2  58s    KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-2
  Normal   RestartNodes                                              18s    KubeDB Ops-manager Operator  Successfully restarted all nodes
  Normal   Starting                                                  18s    KubeDB Ops-manager Operator  Resuming ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                18s    KubeDB Ops-manager Operator  Successfully resumed ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: zkops-update-issuer

Now, Let’s exec into a zookeeper node and find out the ca subject to see if it matches the one we have provided.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ keytool -list -v -keystore /var/private/ssl/server.keystore.jks -storepass fdjk2dgffqn9 | grep 'Issuer'
Issuer: O=kubedb-updated, CN=ca-updated
Issuer: O=kubedb-updated, CN=ca-updated

We can see from the above output that, the subject name matches the subject name of the new ca certificate that we have created. So, the issuer is changed successfully.

Remove TLS from the Database

Now, we are going to remove TLS from this database using a ZooKeeperOpsRequest.

Create ZooKeeperOpsRequest

Below is the YAML of the ZooKeeperOpsRequest CRO that we are going to create,

apiVersion: ops.kubedb.com/v1alpha1
kind: ZooKeeperOpsRequest
metadata:
  name: zkops-remove
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: zk-quickstart
  tls:
    remove: true

Here,

  • spec.databaseRef.name specifies that we are performing reconfigure TLS operation on zk-quickstart cluster.
  • spec.type specifies that we are performing ReconfigureTLS on ZooKeeper.
  • spec.tls.remove specifies that we want to remove tls from this cluster.

Let’s create the ZooKeeperOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/zookeeper/reconfigure-tls/zkops-remove.yaml
zookeeperopsrequest.ops.kubedb.com/zkops-remove created

Verify TLS Removed Successfully

Let’s wait for ZooKeeperOpsRequest to be Successful. Run the following command to watch ZooKeeperOpsRequest CRO,

$ kubectl get zookeeperopsrequest -n demo zkops-remove
NAME           TYPE             STATUS        AGE
zkops-remove   ReconfigureTLS   Successful    105s

We can see from the above output that the ZooKeeperOpsRequest has succeeded. If we describe the ZooKeeperOpsRequest we will get an overview of the steps that were followed.

$ kubectl describe zookeeperopsrequest -n demo zkops-remove
Name:         zkops-remove
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         ZooKeeperOpsRequest
Metadata:
  Creation Timestamp:  2024-11-04T13:39:19Z
  Generation:          1
  Resource Version:    2156556
  UID:                 8f669fe1-169f-4446-9d12-bf959216e2e0
Spec:
  Apply:  IfReady
  Database Ref:
    Name:  zk-quickstart
  Tls:
    Remove:  true
  Type:      ReconfigureTLS
Status:
  Conditions:
    Last Transition Time:  2024-11-04T13:39:19Z
    Message:               ZooKeeper ops-request has started to reconfigure tls for zookeeper nodes
    Observed Generation:   1
    Reason:                ReconfigureTLS
    Status:                True
    Type:                  ReconfigureTLS
    Last Transition Time:  2024-11-04T13:39:27Z
    Message:               successfully reconciled the ZooKeeper with tls configuration
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-11-04T13:41:42Z
    Message:               Successfully restarted all nodes
    Observed Generation:   1
    Reason:                RestartNodes
    Status:                True
    Type:                  RestartNodes
    Last Transition Time:  2024-11-04T13:39:32Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:39:32Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-0
    Last Transition Time:  2024-11-04T13:39:37Z
    Message:               running pod; ConditionStatus:False
    Observed Generation:   1
    Status:                False
    Type:                  RunningPod
    Last Transition Time:  2024-11-04T13:40:22Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:40:22Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-1
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-1
    Last Transition Time:  2024-11-04T13:41:02Z
    Message:               get pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:41:02Z
    Message:               evict pod; ConditionStatus:True; PodName:zk-quickstart-2
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--zk-quickstart-2
    Last Transition Time:  2024-11-04T13:41:42Z
    Message:               Successfully completed reconfigureTLS for zookeeper.
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                    Age    From                         Message
  ----     ------                                                    ----   ----                         -------
  Normal   Starting                                                  2m26s  KubeDB Ops-manager Operator  Start processing for ZooKeeperOpsRequest: demo/zkops-remove
  Normal   Starting                                                  2m26s  KubeDB Ops-manager Operator  Pausing ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                2m26s  KubeDB Ops-manager Operator  Successfully paused ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: zkops-remove
  Normal   UpdatePetSets                                             2m18s  KubeDB Ops-manager Operator  successfully reconciled the ZooKeeper with tls configuration
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-0    2m13s  KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-0  2m13s  KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-0
  Warning  running pod; ConditionStatus:False                        2m8s   KubeDB Ops-manager Operator  running pod; ConditionStatus:False
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-1    83s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-1  83s    KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-1
  Warning  get pod; ConditionStatus:True; PodName:zk-quickstart-2    43s    KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:zk-quickstart-2
  Warning  evict pod; ConditionStatus:True; PodName:zk-quickstart-2  43s    KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:zk-quickstart-2
  Normal   RestartNodes                                              3s     KubeDB Ops-manager Operator  Successfully restarted all nodes
  Normal   Starting                                                  3s     KubeDB Ops-manager Operator  Resuming ZooKeeper database: demo/zk-quickstart
  Normal   Successful                                                3s     KubeDB Ops-manager Operator  Successfully resumed ZooKeeper database: demo/zk-quickstart for ZooKeeperOpsRequest: zkops-remove

Now, Let’s exec into one of the broker node and find out that TLS is disabled or not.

$ kubectl exec -it -n demo zk-quickstart-0 -- bash
Defaulted container "zookeeper" out of: zookeeper, zookeeper-init (init)
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ cat ../conf/zoo.cfg
4lw.commands.whitelist=*
dataDir=/data
tickTime=2000
initLimit=10
syncLimit=2
clientPort=2181
globalOutstandingLimit=1000
preAllocSize=65536
snapCount=10000
commitLogCount=500
snapSizeLimitInKb=4194304
maxCnxns=0
maxClientCnxns=60
minSessionTimeout=4000
maxSessionTimeout=40000
autopurge.snapRetainCount=3
autopurge.purgeInterval=1
quorumListenOnAllIPs=false
admin.serverPort=8080
authProvider.1=org.apache.zookeeper.server.auth.SASLAuthenticationProvider
reconfigEnabled=true
standaloneEnabled=false
dynamicConfigFile=/data/zoo.cfg.dynamic
zookeeper@zk-quickstart-0:/apache-zookeeper-3.8.3-bin$ 

So, we can see from the above that, output that tls is disabled successfully.

Cleaning up

To cleanup the Kubernetes resources created by this tutorial, run:

kubectl delete opsrequest zkops-add-tls zkops-remove zkops-rotate zkops-update-issuer
kubectl delete zookeeper -n demo zk-quickstart
kubectl delete issuer -n demo zk-issuer zk-new-issuer
kubectl delete ns demo

Next Steps