Kubernetes-Kafka unable to write message on topic - docker

Question

I am trying to write data on kafka topic but, stuck with some errors. Below are my configuration & error details.
Kubernetes Service:
kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kafka-service NodePort 10.105.214.246 <none> 9092:30998/TCP 17m
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4d
zoo1 ClusterIP 10.101.3.128 <none> 2181/TCP,2888/TCP,3888/TCP 20m
Kubernetes Pods:
kubectl get pods
NAME READY STATUS RESTARTS AGE
kafka-broker0-69c97b67f-4pmw9 1/1 Running 1 1m
zookeeper-deployment-1-796f9d9bcc-cr756 1/1 Running 0 20m
Kafka Docker Process:
docker ps | grep kafka
f79cd0196083 wurstmeister/kafka#sha256:d04dafd2b308f26dbeed8454f67c321579c2818c1eff5e8f695e14a19b1d599b "start-kafka.sh" About a minute ago Up About a minute k8s_kafka_kafka-broker0-69c97b67f-4pmw9_default_a747d38a-0da6-11e9-bd84-fa163e7d3173_1
75393e9e25c1 k8s.gcr.io/pause-amd64:3.1 "/pause" About a minute ago Up About a minute k8s_POD_kafka-broker0-69c97b67f-4pmw9_default_a747d38a-0da6-11e9-bd84-fa163e7d3173_0
Topic test is created successfully in Kafka as shown below:
docker exec k8s_kafka_kafka-broker0-69c97b67f-4pmw9_default_a747d38a-0da6-11e9-bd84-fa163e7d3173_1 /opt/kafka_2.12-2.1.0/bin/kafka-topics.sh --list --zookeeper zoo1:2181
OR
docker exec k8s_kafka_kafka-broker0-69c97b67f-4pmw9_default_a747d38a-0da6-11e9-bd84-fa163e7d3173_1 /opt/kafka_2.12-2.1.0/bin/kafka-topics.sh --list --zookeeper 10.101.3.128:2181
Output of above command:
test
As the topic is available to write data on it, I had executed below command with host machine IP 10.225.36.98 or with service IP 10.105.214.246 :
kubectl exec kafka-broker0-69c97b67f-4pmw9 -c kafka -i -t --
/opt/kafka_2.12-2.1.0/bin/kafka-console-producer.sh [ --broker-list
10.225.36.98:30998 --topic test ]
>{"k":"v"}
But none of them is working for me & throw below exception:
[2019-01-01 09:26:52,215] ERROR Error when sending message to topic test with key: null, value: 9 bytes with error:
(org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.
>[2019-01-01 09:27:59,513] WARN [Producer clientId=console-producer]
Connection to node -1 (/10.225.36.98:30998) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
When tried to write on broker with hostname kafka:
kubectl exec kafka-broker0-69c97b67f-4pmw9 -c kafka -i -t -- /opt/kafka_2.12-2.1.0/bin/kafka-console-producer.sh [ --broker-list kafka:9092 --topic test ]
[2019-01-01 09:34:41,293] WARN Couldn't resolve server kafka:9092 from bootstrap.servers as DNS resolution failed for kafka
(org.apache.kafka.clients.ClientUtils)
org.apache.kafka.common.KafkaException: Failed to construct kafka producer
As the host & service IP were not working, I tried with pod IP, but get test=LEADER_NOT_AVAILABLE error.
kubectl exec kafka-broker0-69c97b67f-4pmw9 -c kafka -i -t -- /opt/kafka_2.12-2.1.0/bin/kafka-console-producer.sh [ --broker-list 172.17.0.7:9092 --topic test ]
>{"k":"v"}
[2019-01-01 09:52:30,733] WARN [Producer clientId=console-producer] Error while fetching metadata with correlation id 1 : {test=LEADER_NOT_AVAILABLE} (org.apache.kafka.clients.NetworkClient)
After searching Google I found command to get list of available brokers in Zookeeper. So I tried to run it from container & stuck on below error:
bash-4.4# ./opt/zookeeper/bin/zkCli.sh -server zoo1:2181 ls /brokers/ids
Connecting to zoo1:2181
Exception from Zookeeper:
2019-01-01 09:18:05,215 [myid:] - INFO [main:Environment#100] - Client environment:zookeeper.version=3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT
2019-01-01 09:18:05,219 [myid:] - INFO [main:Environment#100] - Client environment:host.name=zookeeper-deployment-1-796f9d9bcc-cr756
2019-01-01 09:18:05,220 [myid:] - INFO [main:Environment#100] - Client environment:java.version=1.8.0_151
2019-01-01 09:18:05,223 [myid:] - INFO [main:Environment#100] - Client environment:java.vendor=Oracle Corporation
2019-01-01 09:18:05,223 [myid:] - INFO [main:Environment#100] - Client environment:java.home=/usr/lib/jvm/java-1.8-openjdk/jre
2019-01-01 09:18:05,223 [myid:] - INFO [main:Environment#100] - Client environment:java.class.path=/opt/zookeeper/bin/../build/classes:/opt/zookeeper/b
in/../build/lib/*.jar:/opt/zookeeper/bin/../lib/slf4j-log4j12-1.6.1.jar:/opt/zookeeper/bin/../lib/slf4j-api-
1.6.1.jar:/opt/zookeeper/bin/../lib/netty-3.10.5.Final.jar:/opt/zookeeper/bin/../lib/log4j-
1.2.16.jar:/opt/zookeeper/bin/../lib/jline-0.9.94.jar:/opt/zookeeper/bin/../zookeeper-3.4.10.jar:/opt/zookeeper/bin/../src/java/lib/*.jar:/opt/zookeeper/bin/../conf:
2019-01-01 09:18:05,223 [myid:] - INFO [main:Environment#100] - Client environment:java.library.path=/usr/lib/jvm/java-1.8-
openjdk/jre/lib/amd64/server:/usr/lib/jvm/java-1.8-openjdk/jre/lib/amd64:/usr/lib/jvm/java-1.8-openjdk/jre/../lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2019-01-01 09:18:05,223 [myid:] - INFO [main:Environment#100] - Client environment:java.io.tmpdir=/tmp
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:java.compiler=<NA>
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:os.name=Linux
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:os.arch=amd64
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:os.version=3.10.0-693.11.6.el7.x86_64
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:user.name=root
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:user.home=/root
2019-01-01 09:18:05,224 [myid:] - INFO [main:Environment#100] - Client environment:user.dir=/
2019-01-01 09:18:05,225 [myid:] - INFO [main:ZooKeeper#438] - Initiating client connection, connectString=zoo1:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher#25f38edc
2019-01-01 09:18:05,259 [myid:] - INFO [main-SendThread(zoo1.default.svc.cluster.local:2181):ClientCnxn$SendThread#1032] - Opening socket connection to server zoo1.default.svc.cluster.local/10.101.3.128:2181. Will not attempt to authenticate using SASL (unknown error)
2019-01-01 09:18:35,280 [myid:] - WARN [main-SendThread(zoo1.default.svc.cluster.local:2181):ClientCnxn$SendThread#1108] - Client session timed out, have not heard from server in 30027ms for sessionid 0x0
2019-01-01 09:18:35,282 [myid:] - INFO [main-SendThread(zoo1.default.svc.cluster.local:2181):ClientCnxn$SendThread#1156] - Client session timed out, have not heard from server in 30027ms for sessionid 0x0, closing socket connection and attempting reconnect
Exception in thread "main" org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /brokers/ids
at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:1532)
at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:1560)
at org.apache.zookeeper.ZooKeeperMain.processZKCmd(ZooKeeperMain.java:731)
at org.apache.zookeeper.ZooKeeperMain.processCmd(ZooKeeperMain.java:599)
at org.apache.zookeeper.ZooKeeperMain.run(ZooKeeperMain.java:362)
at org.apache.zookeeper.ZooKeeperMain.main(ZooKeeperMain.java:290)
I also tried to create Kafka service of type LoadBalancer type, but, No LoadBalancer IP is assigned to service.
References to resolve this issue:
https://rmoff.net/2018/08/02/kafka-listeners-explained/
https://github.com/wurstmeister/kafka-docker/wiki/Connectivity#additional-listener-information
https://github.com/kubernetes/contrib/issues/2891
https://dzone.com/articles/ultimate-guide-to-installing-kafka-docker-on-kuber
https://github.com/wurstmeister/kafka-docker/issues/85
Any help would be appreciated.

Answer 1

Try following command to send data to topic:
docker exec k8s_kafka_kafka-broker0-69c97b67f-4pmw9_default_a747d38a-0da6-11e9-bd84-fa163e7d3173_1
/opt/kafka_2.12-2.1.0/bin/kafka-console-producer.sh
--broker-list kafka-service:30998 --topic test