charts/bitnami/kafka

Kafka

Kafka is a distributed streaming platform used for building real-time data pipelines and streaming apps. It is horizontally scalable, fault-tolerant, wicked fast, and runs in production in thousands of companies.

TL;DR;

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-release bitnami/kafka

Introduction

This chart bootstraps a Kafka deployment on a Kubernetes cluster using the Helm package manager.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.

Prerequisites

• Kubernetes 1.12+
• Helm 2.11+ or Helm 3.0-beta3+
• PV provisioner support in the underlying infrastructure

Installing the Chart

To install the chart with the release name my-release:

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-release bitnami/kafka

These commands deploy Kafka on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.

Tip

: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Parameters

The following tables lists the configurable parameters of the Kafka chart and their default values per section/component:

Global parameters

Parameter	Description	Default
global.imageRegistry	Global Docker image registry	nil
global.imagePullSecrets	Global Docker registry secret names as an array	[] (does not add image pull secrets to deployed pods)
global.storageClass	Global storage class for dynamic provisioning	nil

Common parameters

Parameter	Description	Default
nameOverride	String to partially override kafka.fullname	nil
fullnameOverride	String to fully override kafka.fullname	nil
clusterDomain	Default Kubernetes cluster domain	cluster.local

Kafka parameters

Parameter	Description	Default
image.registry	Kafka image registry	docker.io
image.repository	Kafka image name	bitnami/kafka
image.tag	Kafka image tag	{TAG_NAME}
image.pullPolicy	Kafka image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
image.debug	Set to true if you would like to see extra information on logs	false
config	Configuration file for Kafka. Auto-generated based on other parameters when not specified	nil
existingConfigmap	Name of existing ConfigMap with Kafka configuration	nil
allowPlaintextListener	Allow to use the PLAINTEXT listener	true
listeners	The address(es) the socket server listens on	[]
advertisedListeners	The address(es) (hostname:port) the broker will advertise to producers and consumers	[]
listenerSecurityProtocolMap	The protocol->listener mapping	nil
interBrokerListenerName	The listener that the brokers should communicate on	nil
brokerId	ID of the Kafka node	nil
heapOpts	Kafka's Java Heap size	-Xmx1024m -Xms1024m
deleteTopicEnable	Switch to enable topic deletion or not	false
autoCreateTopicsEnable	Switch to enable auto creation of topics. Enabling auto creation of topics not recommended for production or similar environments	false
logFlushIntervalMessages	The number of messages to accept before forcing a flush of data to disk	10000
logFlushIntervalMs	The maximum amount of time a message can sit in a log before we force a flush	1000
logRetentionBytes	A size-based retention policy for logs	_1073741824
logRetentionCheckIntervalMs	The interval at which log segments are checked to see if they can be deleted	300000
logRetentionHours	The minimum age of a log file to be eligible for deletion due to age	168
logSegmentBytes	The maximum size of a log segment file. When this size is reached a new log segment will be created	_1073741824
logsDirs	A comma separated list of directories under which to store log files	/bitnami/kafka/data
maxMessageBytes	The largest record batch size allowed by Kafka	1000012
defaultReplicationFactor	Default replication factors for automatically created topics	1
offsetsTopicReplicationFactor	The replication factor for the offsets topic	1
transactionStateLogReplicationFactor	The replication factor for the transaction topic	1
transactionStateLogMinIsr	Overridden min.insync.replicas config for the transaction topic	1
numIoThreads	The number of threads doing disk I/O	8
numNetworkThreads	The number of threads handling network requests	3
numPartitions	The default number of log partitions per topic	1
numRecoveryThreadsPerDataDir	The number of threads per data directory to be used for log recovery at startup and flushing at shutdown	1
socketReceiveBufferBytes	The receive buffer (SO_RCVBUF) used by the socket server	102400
socketRequestMaxBytes	The maximum size of a request that the socket server will accept (protection against OOM)	_104857600
socketSendBufferBytes	The send buffer (SO_SNDBUF) used by the socket server	102400
zookeeperConnectionTimeoutMs	Timeout in ms for connecting to Zookeeper	6000
sslEndpointIdentificationAlgorithm	The endpoint identification algorithm to validate server hostname using server certificate	https
extraEnvVars	Extra environment variables to add to kafka pods	[]
auth.enabled	Switch to enable the kafka authentication	false
auth.certificatesSecret	Name of the existing secret containing the certificate files that will be used by Kafka	nil
auth.certificatesPassword	Password for the above certificates if they are password protected	nil
auth.brokerUser	Kafka client user	user
auth.brokerPassword	Kafka client password	nil
auth.interBrokerUser	Kafka inter broker communication user	admin
auth.interBrokerPassword	Kafka inter broker communication password	nil
auth.zookeeperUser	Kafka Zookeeper user	nil
auth.zookeeperPassword	Kafka Zookeeper password	nil
auth.existingSecret	Name of the existing secret containing credentials for brokerUser, interBrokerUser and zookeeperUser	nil
log4j	An optional log4j.properties file to overwrite the default of the Kafka brokers.	nil
existingLog4jConfigMap	The name of an existing ConfigMap containing a log4j.properties file.	nil

Statefulset parameters

Parameter	Description	Default
replicaCount	Number of Kafka nodes	1
updateStrategy	Update strategy for the stateful set	RollingUpdate
rollingUpdatePartition	Partition update strategy	nil
podLabels	Kafka pod labels	{} (evaluated as a template)
podAnnotations	Kafka Pod annotations	{} (evaluated as a template)
affinity	Affinity for pod assignment	{} (evaluated as a template)
nodeSelector	Node labels for pod assignment	{} (evaluated as a template)
tolerations	Tolerations for pod assignment	[] (evaluated as a template)
podSecurityContext	Kafka pods' Security Context	{}
containerSecurityContext	Kafka containers' Security Context	{}
resources.limits	The resources limits for Kafka containers	{}
resources.requests	The requested resources for Kafka containers	{}
livenessProbe	Liveness probe configuration for Kafka	Check values.yaml file
readinessProbe	Readiness probe configuration for Kafka	Check values.yaml file
pdb.create	Enable/disable a Pod Disruption Budget creation	false
pdb.minAvailable	Minimum number/percentage of pods that should remain scheduled	nil
pdb.maxUnavailable	Maximum number/percentage of pods that may be made unavailable	1
sidecars	Attach additional sidecar containers to the Kafka pod	{}

Exposure parameters

Parameter	Description	Default
service.type	Kubernetes Service type	ClusterIP
service.port	Kafka port	9092
service.sslPort	Kafka SSL port	9093
service.nodePorts.kafka	Kubernetes Kafka node port	""
service.nodePorts.ssl	Kubernetes Kafka SSL node port	""
service.loadBalancerIP	loadBalancerIP for Kafka Service	nil
service.loadBalancerSourceRanges	Address(es) that are allowed when service is LoadBalancer	[]
service.annotations	Service annotations	{}(evaluated as a template)
externalAccess.enabled	Enable Kubernetes external cluster access to Kafka brokers	false
externalAccess.autoDiscovery.enabled	Enable using an init container to auto-detect external IPs/ports by querying the K8s API	false
externalAccess.autoDiscovery.image.registry	Init container auto-discovery image registry (kubectl)	docker.io
externalAccess.autoDiscovery.image.repository	Init container auto-discovery image name (kubectl)	bitnami/kubectl
externalAccess.autoDiscovery.image.tag	Init container auto-discovery image tag (kubectl)	{TAG_NAME}
externalAccess.autoDiscovery.image.pullPolicy	Init container auto-discovery image pull policy (kubectl)	Always
externalAccess.autoDiscovery.resources.limits	Init container auto-discovery resource limits	{}
externalAccess.autoDiscovery.resources.requests	Init container auto-discovery resource requests	{}
externalAccess.service.type	Kubernetes Servive type for external access. It can be NodePort or LoadBalancer	LoadBalancer
externalAccess.service.port	Kafka port used for external access when service type is LoadBalancer	19092
externalAccess.service.loadBalancerIPs	Array of load balancer IPs for Kafka brokers	[]
externalAccess.service.loadBalancerSourceRanges	Address(es) that are allowed when service is LoadBalancer	[]
externalAccess.service.domain	Domain or external ip used to configure Kafka external listener when service type is NodePort	nil
externalAccess.service.nodePorts	Array of node ports used to configure Kafka external listener when service type is NodePort	[]
externalAccess.service.annotations	Service annotations for external access	{}(evaluated as a template)

Persistence parameters

Parameter	Description	Default
persistence.enabled	Enable Kafka data persistence using PVC, note that Zookeeper persistence is unaffected	true
persistence.existingClaim	Provide an existing PersistentVolumeClaim, the value is evaluated as a template	nil
persistence.storageClass	PVC Storage Class for Kafka data volume	nil
persistence.accessMode	PVC Access Mode for Kafka data volume	ReadWriteOnce
persistence.size	PVC Storage Request for Kafka data volume	8Gi
persistence.annotations	Annotations for the PVC	{}(evaluated as a template)

RBAC parameters

Parameter	Description	Default
serviceAccount.create	Enable creation of ServiceAccount for Kafka pods	true
serviceAccount.name	Name of the created serviceAccount	Generated using the kafka.fullname template
rbac.create	Weather to create & use RBAC resources or not	false

Volume Permissions parameters

Parameter	Description	Default
volumePermissions.enabled	Enable init container that changes the owner and group of the persistent volume(s) mountpoint to runAsUser:fsGroup	false
volumePermissions.image.registry	Init container volume-permissions image registry	docker.io
volumePermissions.image.repository	Init container volume-permissions image name	bitnami/minideb
volumePermissions.image.tag	Init container volume-permissions image tag	buster
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	Always
volumePermissions.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
volumePermissions.resources.limits	Init container volume-permissions resource limits	{}
volumePermissions.resources.requests	Init container volume-permissions resource requests	{}

Metrics parameters

Parameter	Description	Default
metrics.kafka.enabled	Whether or not to create a standalone Kafka exporter to expose Kafka metrics	false
metrics.kafka.image.registry	Kafka exporter image registry	docker.io
metrics.kafka.image.repository	Kafka exporter image name	bitnami/kafka-exporter
metrics.kafka.image.tag	Kafka exporter image tag	{TAG_NAME}
metrics.kafka.image.pullPolicy	Kafka exporter image pull policy	IfNotPresent
metrics.kafka.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
metrics.kafka.resources.limits	Kafka Exporter container resource limits	{}
metrics.kafka.resources.requests	Kafka Exporter container resource requests	{}
metrics.kafka.service.type	Kubernetes service type (ClusterIP, NodePort or LoadBalancer) for Kafka Exporter	ClusterIP
metrics.kafka.service.port	Kafka Exporter Prometheus port	9308
metrics.kafka.service.nodePort	Kubernetes HTTP node port	""
metrics.kafka.service.annotations	Annotations for Prometheus metrics service	Check values.yaml file
metrics.kafka.service.loadBalancerIP	loadBalancerIP if service type is LoadBalancer	nil
metrics.kafka.service.clusterIP	Static clusterIP or None for headless services	nil
metrics.jmx.enabled	Whether or not to expose JMX metrics to Prometheus	false
metrics.jmx.image.registry	JMX exporter image registry	docker.io
metrics.jmx.image.repository	JMX exporter image name	bitnami/jmx-exporter
metrics.jmx.image.tag	JMX exporter image tag	{TAG_NAME}
metrics.jmx.image.pullPolicy	JMX exporter image pull policy	IfNotPresent
metrics.jmx.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
metrics.jmx.resources.limits	JMX Exporter container resource limits	{}
metrics.jmx.resources.requests	JMX Exporter container resource requests	{}
metrics.jmx.service.type	Kubernetes service type (ClusterIP, NodePort or LoadBalancer) for JMX Exporter	ClusterIP
metrics.jmx.service.port	JMX Exporter Prometheus port	5556
metrics.jmx.service.nodePort	Kubernetes HTTP node port	""
metrics.jmx.service.annotations	Annotations for Prometheus metrics service	Check values.yaml file
metrics.jmx.service.loadBalancerIP	loadBalancerIP if service type is LoadBalancer	nil
metrics.jmx.service.clusterIP	Static clusterIP or None for headless services	nil
metrics.jmx.whitelistObjectNames	Allows setting which JMX objects you want to expose to via JMX stats to JMX Exporter	(see values.yaml)
metrics.jmx.config	Configuration file for JMX exporter	(see values.yaml)
metrics.jmx.existingConfigmap	Name of existing ConfigMap with JMX exporter configuration	nil
metrics.serviceMonitor.enabled	if true, creates a Prometheus Operator ServiceMonitor (requires metrics.kafka.enabled or metrics.jmx.enabled to be true)	false
metrics.serviceMonitor.namespace	Namespace which Prometheus is running in	monitoring
metrics.serviceMonitor.interval	Interval at which metrics should be scraped	nil
metrics.serviceMonitor.scrapeTimeout	Timeout after which the scrape is ended	nil (Prometheus Operator default value)
metrics.serviceMonitor.selector	ServiceMonitor selector labels	nil (Prometheus Operator default value)

Zookeeper chart parameters

Parameter	Description	Default
zookeeper.enabled	Switch to enable or disable the Zookeeper helm chart	true
zookeeper.persistence.enabled	Enable Zookeeper persistence using PVC	true
externalZookeeper.servers	Server or list of external Zookeeper servers to use	[]

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

helm install my-release \
  --set replicaCount=3 \
  bitnami/kafka

The above command deploys Kafka with 3 brokers (replicas).

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

helm install my-release -f values.yaml bitnami/kafka

Tip

: You can use the default values.yaml

Configuration and installation details

Rolling VS Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Production configuration and horizontal scaling

This chart includes a values-production.yaml file where you can find some parameters oriented to production configuration in comparison to the regular values.yaml. You can use this file instead of the default one.

• Number of Kafka nodes:

- replicaCount: 1
+ replicaCount: 3

• Allow to use the PLAINTEXT listener:

- allowPlaintextListener: true
+ allowPlaintextListener: false

• Default replication factors for automatically created topics:

- defaultReplicationFactor: 1
+ defaultReplicationFactor: 3

• Allow auto creation of topics.

- autoCreateTopicsEnable: true
+ autoCreateTopicsEnable: false

• The replication factor for the offsets topic:

- offsetsTopicReplicationFactor: 1
+ offsetsTopicReplicationFactor: 3

• The replication factor for the transaction topic:

- transactionStateLogReplicationFactor: 1
+ transactionStateLogReplicationFactor: 3

• Overridden min.insync.replicas config for the transaction topic:

- transactionStateLogMinIsr: 1
+ transactionStateLogMinIsr: 3

• Switch to enable the kafka authentication:

- auth.enabled: false
+ auth.enabled: true

• Whether or not to create a separate Kafka exporter:

- metrics.kafka.enabled: false
+ metrics.kafka.enabled: true

• Whether or not to expose JMX metrics to Prometheus:

- metrics.jmx.enabled: false
+ metrics.jmx.enabled: true

• Zookeeper chart metrics configuration:

+ zookeeper.metrics.enabled: true

To horizontally scale this chart once it has been deployed, you can upgrade the deployment using a new value for the replicaCount parameter.

Setting custom parameters

Any environment variable beginning with KAFKA_CFG_ will be mapped to its corresponding Kafka key. For example, use KAFKA_CFG_BACKGROUND_THREADS in order to set background.threads. In order to pass custom environment variables use the extraEnvVars property.

Enable security for Kafka and Zookeeper

If you enabled the authentication for Kafka, the SASL_SSL listener will be configured with your provided inputs. In particular you can set the following pair of credentials:

• brokerUser/brokerPassword: To authenticate kafka clients against kafka brokers
• interBrokerUser/interBrokerPassword: To authenticate kafka brokers between them.
• zookeeperUser/zookeeperPassword: In the case that the Zookeeper chart is deployed with SASL authentication enabled.

In order to configure the authentication, you must create a secret containing the kafka.keystore.jks and kafka.trustore.jks certificates and pass the secret name with the --auth.certificatesSecret option when deploying the chart.

You can create the secret and deploy the chart with authentication using the following parameters:

auth.enabled=true
auth.brokerUser=brokerUser
auth.brokerPassword=brokerPassword
auth.interBrokerUser=interBrokerUser
auth.interBrokerPassword=interBrokerPassword
auth.zookeeperUser=zookeeperUser
auth.zookeeperPassword=zookeeperPassword
zookeeper.auth.enabled=true
zookeeper.auth.serverUsers=zookeeperUser
zookeeper.auth.serverPasswords=zookeeperPassword
zookeeper.auth.clientUser=zookeeperUser
zookeeper.auth.clientPassword=zookeeperPassword
auth.certificatesSecret=kafka-certificates

Note

: If the JKS files are password protected (recommended), you will need to provide the password to get access to the keystores. To do so, use the auth.certificatesPassword option to provide your password.

Accessing Kafka brokers from outside the cluster

In order to access Kafka Brokers from outside the cluster, an additional listener and advertised listener must be configured. Additionally, a specific service per kafka pod will be created.

There are two ways of configuring external access. Using LoadBalancer services or using NodePort services.

Using LoadBalancer services

You have two alternatives to use LoadBalancer services:

• Option A) Use random load balancer IPs using an initContainer that waits for the IPs to be ready and discover them automatically.

externalAccess.enabled=true
externalAccess.service.type=LoadBalancer
externalAccess.service.port=19092
externalAccess.autoDiscovery.enabled=true
serviceAccount.create=true
rbac.create=true

Note: This option requires creating RBAC rules on clusters where RBAC policies are enabled.

• Option B) Manually specify the load balancer IPs:

externalAccess.enabled=true
externalAccess.service.type=LoadBalancer
externalAccess.service.port=19092
externalAccess.service.loadBalancerIPs[0]='external-ip-1'
externalAccess.service.loadBalancerIPs[1]='external-ip-2'}

Note: You need to know in advance the load balancer IPs so each Kafka broker advertised listener is configured with it.

Using NodePort services

You have two alternatives to use NodePort services:

• Option A) Use random node ports using an initContainer that discover them automatically.

externalAccess.enabled=true
externalAccess.service.type=NodePort
externalAccess.autoDiscovery.enabled=true
serviceAccount.create=true
rbac.create=true

Note: This option requires creating RBAC rules on clusters where RBAC policies are enabled.

• Option B) Manually specify the node ports:

externalAccess.enabled=true
externalAccess.service.type=NodePort
externalAccess.serivce.nodePorts[0]='node-port-1'
externalAccess.serivce.nodePorts[1]='node-port-2'

Note: You need to know in advance the node ports that will be exposed so each Kafka broker advertised listener is configured with it.

The pod will try to get the external ip of the node using curl -s https://ipinfo.io/ip unless externalAccess.service.domain is provided.

Sidecars

If you have a need for additional containers to run within the same pod as Kafka (e.g. an additional metrics or logging exporter), you can do so via the sidecars config parameter. Simply define your container according to the Kubernetes container spec.

sidecars:
  - name: your-image-name
    image: your-image
    imagePullPolicy: Always
    ports:
      - name: portname
       containerPort: 1234

Persistence

The Bitnami Kafka image stores the Kafka data at the /bitnami/kafka path of the container.

Persistent Volume Claims are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube. See the Parameters section to configure the PVC or to disable persistence.

Adjust permissions of persistent volume mountpoint

As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it.

By default, the chart is configured to use Kubernetes Security Context to automatically change the ownership of the volume. However, this feature does not work in all Kubernetes distributions. As an alternative, this chart supports using an initContainer to change the ownership of the volume before mounting it in the final destination.

You can enable this initContainer by setting volumePermissions.enabled to true.

Upgrading

To 10.0.0

If you are setting the config or log4j parameter, backwards compatibility is not guaranteed, because the KAFKA_MOUNTED_CONFDIR has moved from /opt/bitnami/kafka/conf to /bitnami/kafka/config. In order to continue using these parameters, you must also upgrade your image to docker.io/bitnami/kafka:2.4.1-debian-10-r38 or later.

To 9.0.0

Backwards compatibility is not guaranteed you adapt your values.yaml to the new format. Here you can find some parameters that were renamed on this major version:

- securityContext.enabled
- securityContext.fsGroup
- securityContext.fsGroup
+ podSecurityContext
- externalAccess.service.loadBalancerIP
+ externalAccess.service.loadBalancerIPs
- externalAccess.service.nodePort
+ externalAccess.service.nodePorts
- metrics.jmx.configMap.enabled
- metrics.jmx.configMap.overrideConfig
+ metrics.jmx.config
- metrics.jmx.configMap.overrideName
+ metrics.jmx.existingConfigmap

Ports names were prefixed with the protocol to comply with Istio (see https://istio.io/docs/ops/deployment/requirements/).

To 8.0.0

There is not backwards compatibility since the brokerID changes to the POD_NAME. For more information see this PR.

To 7.0.0

Backwards compatibility is not guaranteed when Kafka metrics are enabled, unless you modify the labels used on the exporter deployments. Use the workaround below to upgrade from versions previous to 7.0.0. The following example assumes that the release name is kafka:

helm upgrade kafka bitnami/kafka --version 6.1.8 --set metrics.kafka.enabled=false
helm upgrade kafka bitnami/kafka --version 7.0.0 --set metrics.kafka.enabled=true

To 2.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 2.0.0. The following example assumes that the release name is kafka:

kubectl delete statefulset kafka-kafka --cascade=false
kubectl delete statefulset kafka-zookeeper --cascade=false

To 1.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is kafka:

kubectl delete statefulset kafka-kafka --cascade=false
kubectl delete statefulset kafka-zookeeper --cascade=false