Add Kafka as a Receiver

You can use Elasticsearch, Kafka and Fluentd as log receivers in KubeSphere. This tutorial demonstrates:

• Deploy strimzi-kafka-operator and then create a Kafka cluster and a Kafka topic by creating Kafka and KafkaTopic CRDs.
• Add Kafka as a log receiver to receive logs sent from Fluent Bit.
• Verify whether the Kafka cluster is receiving logs using Kafkacat.

Prerequisites

• You need a user granted a role including the permission of Cluster Management. For example, you can log in to the console as admin directly or create a new role with the permission and assign it to a user.
• Before adding a log receiver, you need to enable any of the logging, events or auditing components. For more information, see Enable Pluggable Components. logging is enabled as an example in this tutorial.

Step 1: Create a Kafka Cluster and a Kafka Topic

You can use strimzi-kafka-operator to create a Kafka cluster and a Kafka topic. If you already have a Kafka cluster, you can start from the next step.

1. Install strimzi-kafka-operator in the default namespace:

   helm repo add strimzi https://strimzi.io/charts/
   

   helm install --name kafka-operator -n default strimzi/strimzi-kafka-operator
   

2. Create a Kafka cluster and a Kafka topic in the default namespace by running the following commands. The commands create Kafka and Zookeeper clusters with storage type ephemeral which is emptyDir for demonstration purposes. For other storage types in a production environment, refer to kafka-persistent.

   cat <<EOF | kubectl apply -f -
   apiVersion: kafka.strimzi.io/v1beta1
   kind: Kafka
   metadata:
     name: my-cluster
     namespace: default
   spec:
     kafka:
       version: 2.5.0
       replicas: 3
       listeners:
         plain: {}
         tls: {}
       config:
         offsets.topic.replication.factor: 3
         transaction.state.log.replication.factor: 3
         transaction.state.log.min.isr: 2
         log.message.format.version: '2.5'
       storage:
         type: ephemeral
     zookeeper:
       replicas: 3
       storage:
         type: ephemeral
     entityOperator:
       topicOperator: {}
       userOperator: {}
   ---
   apiVersion: kafka.strimzi.io/v1beta1
   kind: KafkaTopic
   metadata:
     name: my-topic
     namespace: default
     labels:
       strimzi.io/cluster: my-cluster
   spec:
     partitions: 3
     replicas: 3
     config:
       retention.ms: 7200000
       segment.bytes: 1073741824
   EOF
   

3. Run the following command to check Pod status and wait for Kafka and Zookeeper are all up and running.

   $ kubectl -n default get pod 
   NAME                                         READY   STATUS    RESTARTS   AGE
   my-cluster-entity-operator-f977bf457-s7ns2   3/3     Running   0          69m
   my-cluster-kafka-0                           2/2     Running   0          69m
   my-cluster-kafka-1                           2/2     Running   0          69m
   my-cluster-kafka-2                           2/2     Running   0          69m
   my-cluster-zookeeper-0                       1/1     Running   0          71m
   my-cluster-zookeeper-1                       1/1     Running   1          71m
   my-cluster-zookeeper-2                       1/1     Running   1          71m
   strimzi-cluster-operator-7d6cd6bdf7-9cf6t    1/1     Running   0          104m
   

   Run the following command to check the metadata of the Kafka cluster:

   kafkacat -L -b my-cluster-kafka-0.my-cluster-kafka-brokers.default.svc:9092,my-cluster-kafka-1.my-cluster-kafka-brokers.default.svc:9092,my-cluster-kafka-2.my-cluster-kafka-brokers.default.svc:9092
   

Step 2: Add Kafka as a Log Receiver

1. Log in to KubeSphere as admin. Click Platform in the upper-left corner and select Cluster Management.

   Note

   If you have enabled the multi-cluster feature, you can select a specific cluster.

2. On the Cluster Management page, go to Log Receivers in Cluster Settings.

3. Click Add Log Receiver and select Kafka. Enter the Kafka service address and port number, and then click OK to continue.

   Service Address	Port Number
   my-cluster-kafka-0.my-cluster-kafka-brokers.default.svc	9092
   my-cluster-kafka-1.my-cluster-kafka-brokers.default.svc	9092
   my-cluster-kafka-2.my-cluster-kafka-brokers.default.svc	9092

4. Run the following commands to verify whether the Kafka cluster is receiving logs sent from Fluent Bit:

   # Start a util container
   kubectl run --rm utils -it --generator=run-pod/v1 --image arunvelsriram/utils bash
   # Install Kafkacat in the util container
   apt-get install kafkacat
   # Run the following command to consume log messages from kafka topic: my-topic
   kafkacat -C -b my-cluster-kafka-0.my-cluster-kafka-brokers.default.svc:9092,my-cluster-kafka-1.my-cluster-kafka-brokers.default.svc:9092,my-cluster-kafka-2.my-cluster-kafka-brokers.default.svc:9092 -t my-topic
   

Thanks for the feedback. If you have a specific question about how to use KubeSphere, ask it on Slack. Open an issue in the GitHub repo if you want to report a problem or suggest an improvement.