Notable fixes

• Fixed an issue where the platform.confluent.io/roll-delay-interval-seconds annotation was ignored when upgrading the operator. This was causing pods to roll immediately instead of waiting for the configured delay.

• Fixed connector reconciliation for masked sensitive fields in Connect.

  Updated CFK’s connector reconciliation logic to properly handle Connect’s credential masking in the REST API, preventing unnecessary connector updates or restarts when sensitive configuration fields are masked.

• Added auto reconcile capability for cluster link.

• Improved validation for inter-broker protocol (IBP) version and added automatic derivation of IBP for standard Confluent Platform images.

• Fixed metrics TLS configuration to correctly resolve keystore passwords from Vault-injected files when using DirectoryPathInContainer.

• Added support for configuring JMX authentication and access control using CR specifications to secure exposed JMX ports for all Confluent Platform components.

  Important

  This is a breaking change to secure exposed JMX ports. This affects existing deployments that access JMX ports remotely for metrics queries.

  For more information, see JMX Metrics.

• For the list of security and vulnerability issues fixed in this release, see Security Advisories and Security Release Notes.

Notable fixes

• Fixed issues with renewing certificate authorities (CAs) for auto-generated certificates.

  See Manage TLS Certificates for Confluent Platform Using Confluent for Kubernetes.

• Added preventive validation in the CFK webhook for Kafka cluster scale-up and scale-down operations.

• Removed the inter-broker protocol version in Kafka server properties for KRaft-based clusters.

• Improved output of the KafkaRestClass custom resource (CR) status through kubectl.

• Fixed an issue in KRaft migration rollback to ZooKeeper where the required platform.confluent.io/format-cluster-metadata-in-kafka annotation was not being automatically added to the Kafka CR.

• Fixed node port collision for Kafka Token and TokenSASL listeners when using mTLS and RBAC in a Multi-Region Cluster (MRC) setup.

• Fixed load balancer port collision for Kafka Token and TokenSASL listeners when using mTLS and RBAC in a Multi-Region Cluster (MRC) setup.

• For the list of security and vulnerability issues fixed in this release, see Security Advisories and Security Release Notes.

Notable update

A new Confluent Enterprise license is available for the customer-managed Confluent Platform for Confluent Cloud subscription. This license allows you to use self-managed Confluent Platform components exclusively with Confluent Cloud services.

If you encounter the following error when provisioning a new license, you should upgrade to a CFK version, 2.9.7, 2.10.3, 2.11.3, 3.0.1, or later.

secretRef confluent-license: missing subject or contains invalid subject

Notable fixes

• Fixed the empty STATUS in the Schema CRD.

• Fixed the issue where OAuth configuration in the SchemaExporter CRD was ignored when exporting schemas to Confluent Cloud.

• For the list of security and vulnerability issues fixed in this release, see Security Advisories and Security Release Notes.

Notable fixes

For the list of security and vulnerability issues fixed in this release, see Security Advisories and Security Release Notes.

Notable fixes

• Fixed a problem of CFK failing to communicate with the internal Kafka topics when the certificate authority chain had multiple certificates.

• For the list of security and vulnerability issues fixed in this release, see Security Advisories and Security Release Notes.

New features

Role-based access control (RBAC) with mTLS authentication

You can configure RBAC using mTLS authentication on a new Confluent Platform cluster.

See mTLS authentication for MDS.

File-based user store in MDS for RBAC

You can configure RBAC using a file-based user on a new Confluent Platform cluster.

See File-based user store for MDS.

Use CFK to manage Confluent Platform for Apache Flink® environments and applications

You can manage Confluent Platform for Apache Flink application resources using CFK customer resources.

See Manage Flink Applications Using Confluent for Kubernetes.

Notable enhancements and updates

• Now you can mount secrets on the Connect cluster using directory paths.

  See Provide Connect credentials using mounted secrets.

• You can assign custom topic names for the Connect internal topics. Use the spec.internalTopicNames.xxx property in the Connect CR.

  If left unspecified, CFK uses the internally assigned topic names.

  See CFK API reference for Connect.

• CFK shows ConfigOverride options that are set instead of the default values when you query a CR status.

• You can configure external access to JMX metrics using TCP.

  See Monitor Confluent Platform with Confluent for Kubernetes.

• Non-RBAC to RBAC migration

  The workflow to enable RBAC in non-RBAC deployments is now tested and documented along with playbooks for various authentication scenarios.

  See Enable RBAC in running Confluent Platform cluster.

Notable fixes

• An issue causing failure to support the centralized RBAC was fixed. The fix applies to CFK releases 2.9.0 through 2.9.3.

• CFK Connect deployment now correctly sets the updated default values for Log4j.

  This fix will cause your Connect cluster to roll when you upgrade to CFK 2.10.0.

• Removed privileged tag from the tasks in the KRaft controller to support air-gapped installation in the KRaft mode.

• Fixed an intermittent issue during the ZooKeeper to KRaft migration which was resulting in failure to set the owner.

• Fixed an issue that caused an authentication failure when scaling down a Kafka cluster, due to an incorrectly constructed REST call to the Self-Balancing Cluster (SBC) feature.

Known issues

• When deploying CFK to Red Hat OpenShift with Red Hat’s Operator Lifecycle Manager using the OperatorHub, you must use OpenShift version 4.9 or higher.

  This OpenShift version restriction does not apply when deploying CFK to Red Hat OpenShift in the standard way without using the Red Hat Operator Lifecycle Manager.

• When CFK is deployed on an OpenShift cluster with Red Hat’s Operator LIfeCycle Manager/OperatorHub, capturing the support bundle for CFK using the command, kubectl confluent support-bundle --namespace <namespace>, can fail with the following error message:

  panic: runtime error: index out of range [0] with length 0
  

• If the ksqlDB REST endpoint is using the auto-generated certificates, the ksqlDB deployment that points to Confluent Cloud requires trusting the Let’s Encrypt CA.

  For this to work, you must provide a CA bundle through cacerts.pem that contains both (1) the Confluent Cloud CA and (2) the self-signed CA to the ksqlDB CR.

• When TLS is enabled, and when Confluent Control Center (Legacy) uses a different TLS certificate to communicate with MDS or Confluent Cloud Schema Registry, Control Center (Legacy) cannot use an auto-generated TLS certificate to connect to MDS or Confluent Cloud Schema Registry. See Troubleshooting Guide for a workaround.

• When deploying the Schema Registry and Kafka CRs simultaneously, Schema Registry could fail because it cannot create topics with a replication factor of 3. It is because the Kafka brokers have not fully started.

  The workaround is to delete the Schema Registry deployment and re-deploy once Kafka is fully up.

• When deploying an RBAC-enabled Kafka cluster in centralized mode, where another “secondary” Kafka is being used to store RBAC metadata, an error, “License Topic could not be created”, may return on the secondary Kafka cluster.

• A periodic Kubernetes TCP probe on ZooKeeper causes frequent warning messages “client has closed socket” when warning logs are enabled.

• REST Proxy configured with monitoring interceptors is missing the callback handler properties when RBAC is enabled. Interceptor would not work, and you would see an error message in the KafkaRestProxy log.

  As a workaround, manually add configuration overrides as shown in the following KafkaRestProxy CR:

  configOverrides:
    server:
      - confluent.monitoring.interceptor.sasl.login.callback.handler.class=io.confluent.kafka.clients.plugins.auth.token.TokenUserLoginCallbackHandler
      - consumer.confluent.monitoring.interceptor.sasl.login.callback.handler.class=io.confluent.kafka.clients.plugins.auth.token.TokenUserLoginCallbackHandler
      - producer.confluent.monitoring.interceptor.sasl.login.callback.handler.class=io.confluent.kafka.clients.plugins.auth.token.TokenUserLoginCallbackHandler
  

• When configuring source-initiated cluster links with CFK where the source cluster has TLS enabled, do not set spec.tls, and do not set spec.authentication in the ClusterLink CR on the destination cluster if the source cluster has mTLS authentication.

  Instead, in the Destination mode ClusterLink CR, under the spec.configs section, set:

  • local.security.protocol: SSL for mTLS.

  • local.security.protocol: SASL_SSL for SASL authentication with TLS.

  For details about configuring the destination cluster for source-initiated Cluster Linking, see Configure the source-initiated cluster link on the destination cluster.

• The CFK support bundle plugin on Windows systems does not capture all the logs.

  As a workaround, specify the --out-dir flag in the kubectl confluent support-bundle command to provide the output location for the support bundle.

• CFK Blueprints 2.9 and 2.10.0 installation fails due to a missing GLIBC dependency.

  The issue was fixed in CFK Blueprints 2.11.0 release.

Known gaps from Confluent Platform 7.8

CFK 2.10 does not support the following Confluent Platform 7.8 functionality:

• Kafka authentication mechanisms: Kerberos and SASL/Scram

Known gaps in CFK Blueprints

CFK Blueprints 2.10 does not support the following CFK functionality:

• Internal listener authentication change on the running cluster

• A central Confluent Platform cluster serving as the RBAC metadata store for multiple Confluent Platform clusters

• The StaticPortBasedRouting and NodePort external access methods

• Monitoring multiple Kafka clusters in Confluent Control Center (Legacy)

• Configuring and managing KRaft-based clusters

• Using OpenID Connect (OIDC) for authentication