Cannot connect to kafka through SpringBoot (docker) application - spring-boot

Question

Locally started the kafka and I wrote a sample Spring-boot producer. When I run this application it works fine. But when I start the application via docker container, I'm getting below logs "Connection to node 0 could not be established. Broker may not be available."
2019-03-20 06:06:56.023 INFO 1 --- [ XNIO-2 task-1] o.a.k.c.u.AppInfoParser : Kafka version : 1.0.1
2019-03-20 06:06:56.023 INFO 1 --- [ XNIO-2 task-1] o.a.k.c.u.AppInfoParser : Kafka commitId : c0518aa65f25317e
2019-03-20 06:06:56.224 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
2019-03-20 06:06:56.263 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
2019-03-20 06:06:56.355 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
2019-03-20 06:06:56.594 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
2019-03-20 06:06:56.919 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
2019-03-20 06:06:57.877 WARN 1 --- [ad | producer-1] o.a.k.c.NetworkClient : [Producer clientId=producer-1] Connection to node 0 could not be established. Broker may not be available.
Please find the ProducerConfig values below based on the log
2019-03-20 06:06:55.953 INFO 1 --- [ XNIO-2 task-1] o.a.k.c.p.ProducerConfig : ProducerConfig values:
acks = 1
batch.size = 16384
bootstrap.servers = [192.168.0.64:9092]
buffer.memory = 33554432
client.id =
compression.type = none
connections.max.idle.ms = 540000
enable.idempotence = false
interceptor.classes = null
key.serializer = class org.apache.kafka.common.serialization.StringSerializer
linger.ms = 0
max.block.ms = 60000
max.in.flight.requests.per.connection = 5
max.request.size = 1048576
metadata.max.age.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.recording.level = INFO
metrics.sample.window.ms = 30000
partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
receive.buffer.bytes = 32768
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 30000
retries = 0
retry.backoff.ms = 100
sasl.jaas.config = null
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.mechanism = GSSAPI
security.protocol = PLAINTEXT
send.buffer.bytes = 131072
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
ssl.endpoint.identification.algorithm = null
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLS
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.location = null
ssl.truststore.password = null
ssl.truststore.type = JKS
transaction.timeout.ms = 60000
transactional.id = null
value.serializer = class org.springframework.kafka.support.serializer.JsonSerializer
My ProducerConfig as below
#Bean
public Map<String, Object> producerConfigs() {
Map<String, Object> props = new HashMap<>();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.0.64:9092");
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);
return props;
}
Is there any additional configuration required when connecting through docker?

Answer 1

Probably you connect to the wrong port. Do a docker ps:
e.g.
2ca7f0cdddd confluentinc/cp-enterprise-kafka:5.1.2 "/etc/confluent/dock…" 2 weeks ago Up 50 seconds 0.0.0.0:9092->9092/tcp, 0.0.0.0:29092->29092/tcp broker
and use the later broker port: 29092 in the above example.
also usually from your laptop you can access the docker network at localhost.