charts/bitnami/kafka

Kafka

Kafka is an object-relational database management system (ORDBMS) with an emphasis on extensibility and on standards-compliance.

TL;DR;

$ helm install bitnami/kafka

Introduction

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

Prerequisites

• Kubernetes 1.4+ with Beta APIs enabled
• PV provisioner support in the underlying infrastructure

Installing the Chart

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

$ helm install --name my-release bitnami/kafka

The command deploys Kafka on the Kubernetes cluster in the default configuration. The configuration 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.

Configuration

The following tables lists the configurable parameters of the Kafka chart and their default values.

Parameter	Description	Default
image.registry	Kafka image registry	docker.io
image.repository	Kafka Image name	bitnami/kafka
image.tag	Kafka Image tag	{VERSION}
image.pullPolicy	Kafka image pull policy	Always
image.pullSecrets	Specify image pull secrets	nil (does not add image pull secrets to deployed pods)
image.debug	Specify if debug values should be set	false
updateStrategy	Update strategy for the stateful set	1
replicaCount	Number of Kafka nodes	1
config	Configuration file for Kafka	nil
allowPlaintextListener	Allow to use the PLAINTEXT listener	true
listener	The address the socket server listens on.	nil
advertisedListener	Hostname and port the broker will advertise to producers and consumers.	nil
brokerId	ID of the Kafka node	-1
deleteTopicEnable	Switch to enable topic deletion or not.	false
heapOpts	Kafka's Java Heap size.	-Xmx1024m -Xms1024m
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.	/opt/bitnami/kafka/data
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
auth.enabled	Switch to enable the kafka authentication.	false
auth.existingSecret	Name of the existing secret containing credentials for brokerUser, interBrokerUser and zookeeperUser.	nil
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
securityContext.enabled	Enable security context (redis master pod)	true
securityContext.fsGroup	Group ID for the container (redis master pod)	1001
securityContext.runAsUser	User ID for the container (redis master pod)	1001
service.type	Kubernetes Service type	ClusterIP
service.port	Kafka port	9092
persistence.enabled	Enable persistence using PVC	true
persistence.storageClass	PVC Storage Class for Kafka volume	nil
persistence.accessMode	PVC Access Mode for Kafka volume	ReadWriteOnce
persistence.size	PVC Storage Request for Kafka volume	8Gi
persistence.annotations	Annotations for the PVC	{}
nodeSelector	Node labels for pod assignment	{}
tolerations	Toleration labels for pod assignment	[]
resources	CPU/Memory resource requests/limits	Memory: 256Mi, CPU: 250m
livenessProbe.enabled	would you like a livessProbed to be enabled	true
livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	30
livenessProbe.periodSeconds	How often to perform the probe	10
livenessProbe.timeoutSeconds	When the probe times out	5
livenessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
livenessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed	1
readinessProbe.enabled	would you like a readinessProbe to be enabled	true
readinessProbe.initialDelaySeconds	Delay before liveness probe is initiated	5
readinessProbe.periodSeconds	How often to perform the probe	10
readinessProbe.timeoutSeconds	When the probe times out	5
readinessProbe.failureThreshold	Minimum consecutive failures for the probe to be considered failed after having succeeded.	6
readinessProbe.successThreshold	Minimum consecutive successes for the probe to be considered successful after having failed	1
jmx.configMap.enabled	Enable the default ConfigMap for JMX	true
jmx.configMap.overrideConfig	Allows config file to be generated by passing values to ConfigMap	{}
jmx.configMap.overrideName	Allows setting the name of the ConfigMap to be used	""
jmx.port	The jmx port which JMX style metrics are exposed (note: these are not scrapeable by Prometheus)	5555
jmx.whitelistObjectNames	Allows setting which JMX objects you want to expose to via JMX stats to JMX Exporter	(see values.yaml)
metrics.kafka.enabled	Whether or not to create a separate Kafka exporter	false
metrics.kafka.image.registry	Kafka exporter image registry	docker.io
metrics.kafka.image.repository	Kafka exporter image name	danielqsj/kafka-exporter
metrics.kafka.image.tag	Kafka exporter image tag	v1.0.1
metrics.kafka.image.pullPolicy	Kafka exporter image pull policy	Always
metrics.kafka.image.pullSecrets	Specify image pull secrets	nil (does not add image pull secrets to deployed pods)
metrics.kafka.interval	Interval that Prometheus scrapes Kafka metrics when using Prometheus Operator	10s
metrics.kafka.port	Kafka Exporter Port which exposes metrics in Prometheus format for scraping	9308
metrics.kafka.resources	Allows setting resource limits for kafka-exporter pod	{}
metrics.jmx.resources	Allows setting resource limits for jmx sidecar container	{}
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	solsson/kafka-prometheus-jmx-exporter@sha256
metrics.jmx.image.tag	JMX exporter image tag	a23062396cd5af1acdf76512632c20ea6be76885dfc20cd9ff40fb23846557e8
metrics.jmx.image.pullPolicy	JMX exporter image pull policy	Always
metrics.jmx.image.pullSecrets	Specify image pull secrets	nil (does not add image pull secrets to deployed pods)
metrics.jmx.interval	Interval that Prometheus scrapes JMX metrics when using Prometheus Operator	10s
metrics.jmx.port	JMX Exporter Port which exposes metrics in Prometheus format for scraping	5556
zookeeper.enabled	Switch to enable or disable the Zookeeper helm chart	true
externalZookeeper.servers	Server or list of external zookeeper servers to use.	nil

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

$ helm install --name my-release \
  --set kafkaPassword=secretpassword,kafkaDatabase=my-database \
    bitnami/kafka

The above command sets the Kafka kafka account password to secretpassword. Additionally it creates a database named my-database.

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

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

Tip

: You can use the default values.yaml

Production and horizontal scaling

The following repo contains the recommended production settings for Kafka server in an alternative values file. Please read carefully the comments in the values-production.yaml file to set up your environment

To horizontally scale this chart, first download the values-production.yaml file to your local folder, then:

$ helm install --name my-release -f ./values-production.yaml bitnami/kafka
$ kubectl scale statefulset my-kafka-slave --replicas=3

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 among them.
• zookeeperUser/zookeeperPassword: In the case that the Zookeeper chart has been deployed with SASL authentication enabled.

An example of Kafka installed with authentication you can use this command:

helm install --name my-release bitnami/kafka --set auth.enabled=true \
             --set auth.brokerUser=brokerUser --set auth.brokerPassword=brokerPassword \
             --set auth.interBrokerUser=interBrokerUser --set auth.interBrokerPassword=interBrokerPassword \
             --set auth.zookeeperUser=zookeeperUser --set auth.zookeeperPassword=zookeeperPassword \
             --set zookeeper.auth.enabled=-true --set zookeeper.auth.serverUser=zookeeperUser --set zookeeper.auth.serverPassword=zookeeperPassword \
             --set zookeeper.auth.clientUser=zookeeperUser --set zookeeper.auth.clientPassword=zookeeperPassword

Use your custom certificates

Apart from this credentials, the security also relies on a set of certificates. By default, the kafka image bundles dummy certificates that can be overwritten by creating a secret and passing the secret name with the option certificatesSecret:

kubectl create secret generic kafka-certificates --from-file=./ca-key --from-file=./kafka.keystore.jks --from-file=./kafka.truststore.jks

And install with:

helm install --name my-release bitnami/kafka --set auth.enabled=true \
             --set auth.brokerUser=brokerUser --set auth.brokerPassword=brokerPassword \
             --set auth.interBrokerUser=interBrokerUser --set auth.interBrokerPassword=interBrokerPassword \
             --set auth.zookeeperUser=zookeeperUser --set auth.zookeeperPassword=zookeeperPassword \
             --set zookeeper.auth.enabled=-true --set zookeeper.auth.serverUser=zookeeperUser --set zookeeper.auth.serverPassword=zookeeperPassword \
             --set zookeeper.auth.clientUser=zookeeperUser --set zookeeper.auth.clientPassword=zookeeperPassword \
             --set auth.certificatesSecret=kafka-certificates

Note

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

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 Configuration section to configure the PVC or to disable persistence.