Kafka

What does it mean:

akhq             Apache Kafka HQ. web-based user interface and management tool for Apache Kafka clusters.
strimzi          Apache Kafka on Kubernetes

using kafka client

List topics

kubectl exec -it -n kafka kafka-cluster-kafka-0 -- bin/kafka-topics.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --list

Describe topic

kubectl exec -it -n kafka kafka-cluster-kafka-0 -- bin/kafka-topics.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --describe --topic <topic>

Read topic

export TOPIC=<topic> ; kubectl exec -it -n kafka kafka-cluster-kafka-0 -- bin/kafka-console-consumer.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --topic ${TOPIC} --property print.key=true --max-messages 10 --from-beginning --timeout-ms 10000

Describe all topics

kubectl exec -i -n kafka kafka-cluster-kafka-0 -- bin/kafka-topics.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --list | while read i ; do echo '*' $i ; kubectl exec -i -n kafka kafka-cluster-kafka-0 -- bin/kafka-topics.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --describe --topic $i </dev/null ; done

quick overview

kubectl api-resources | grep -i kafka | awk '{print $1}' | while read i ; do echo '*' $i ; kubectl get $i -A ; done

which users exit

kubectl get kafkausers -n kafka

which password does user have

kubectl get secret ifs -o json | jq -r .data.password | base64 -d

list topics

kubectl get kafkatopics -o wide

Kafka version

kubectl exec -it -n kafka kafka-cluster-kafka-0 -- bin/kafka-topics.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --version

bootstrap server internally

kubectl get kafka kafka-cluster -o=jsonpath='{.status.listeners[?(@.type=="tls")].bootstrapServers}{"\n"}'

bootstrap sever external

kubectl get kafka kafka-cluster -o=jsonpath='{.status.listeners[?(@.type=="external")].bootstrapServers}{"\n"}'

produce to topic

bin/kafka-console-producer.sh --broker-list localhost:9092 --topic <topic>

Produce to topic with key.

kubectl exec -it -n kafka kafka-cluster-kafka-0 -- bash
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic <topic> --property "parse.key=true" --property "key.separator=:"
>emp_info: {"emp_id":100,"first_name":"Keshav","last_name":"Lodhi","designation":"DataEngineer"}
CTRL + c
kubectl exec -it -n kafka kafka-cluster-kafka-2 -- bin/kafka-console-consumer.sh --bootstrap-server kafka-cluster-kafka-bootstrap:9092 --topic customer-blacklistmail-dotnet-v1 --property print.key=true --max-messages 10 --from-beginning

read topic

bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic FedoraTopic --from-beginning

zookeeper

Who is the leader.

for i in 0 1 2  ; do echo kafka-cluster-zookeeper-$i $(kubectl exec -it -n kafka kafka-cluster-zookeeper-$i -- bash -c 'echo stat | nc 127.0.0.1 12181' | grep Mode:) ; done