Kafka in Docker not working
I am trying to use wurstmeister\kafka-docker image with docker-compose, but I am having real problems with connecting everything.
All the posts or questions that I check, seems not to have any problems, but I am frankly lost. (And there are at least two questions in SO that try to address the problem)
I believe that the problem is my poor understanding of the networking of docker. So the problem:
I can consume and produce from the same container of kafka, but, when I try to create another container (or use my laptop with a python client) I got several errors related to the advertised.host.name parameter (in the image this parameter is KAFKA_ADVERTISED_HOST_NAME)
I already try setting this variable in lot of ways, but it simply don't work.
So I am looking for a authorative answer (i.e. how to set automatically those parameters and what is it meaning) how to set the docker-compose.yml
This is mine:
zookeeper:
image: wurstmeister/zookeeper
ports:
- "2181:2181"
kafka:
image: wurstmeister/kafka
# hostname: kafka
ports:
- "9092"
links:
- zookeeper:zk
environment:
KAFKA_ADVERTISED_HOST_NAME: "kafka"
KAFKA_ADVERTISED_PORT: "9092"
KAFKA_ZOOKEEPER_CONNECT: "zk:2181"
UPDATE
Following the advise of @dnephin, I modified the start-kafka.sh in the following lines:
...
if [[ -z "$KAFKA_ADVERTISED_PORT" ]]; then
export KAFKA_ADVERTISED_PORT=$(hostname -i)
fi
...
and remove KAFKA_ADVERTISED_HOST_NAME: "kafka" from the docker-compose.yml
I started the containers in the canonical way:
docker-compose up -d
Both of the containers are running:
$ docker-compose ps
Name Command State Ports
-----------------------------------------------------------------------------------------------------------------
infraestructura_kafka_1 start-kafka.sh Up 0.0.0.0:32768->9092/tcp
infraestructura_zookeeper_1 /opt/zookeeper/bin/zkServe ... Up 0.0.0.0:2181->2181/tcp, 2888/tcp, 3888/tcp
Afterwards I did:
docker-compose logs
And everything run smoothly.
For checking the ip addresses:
$ KAFKA_IP=$(docker inspect --format '{{ .NetworkSettings.IPAddress }}' infraestructura_kafka_1)
$ echo $KAFKA_IP
172.17.0.4
and
$ ZK_IP=$(docker inspect --format '{{ .NetworkSettings.IPAddress }}' infraestructura_zookeeper_1)
$ echo $ZK_IP
172.17.0.3
Then I execute in two differents consoles:
A producer:
$ docker run --rm --interactive wurstmeister/kafka /opt/kafka_2.11-0.9.0.1/bin/kafka-console-producer.sh --topic grillo --broker-list 171.17.0.4:9092
A consumer:
$ docker run --rm --interactive wurstmeister/kafka /opt/kafka_2.11-0.9.0.1/bin/kafka-console-consumer.sh --topic grillo --from-beginning --zookeeper 172.17.0.3:2181
Almost immediately, warnings start flying all over the screen:
[2016-03-11 00:39:17,010] WARN Fetching topic metadata with correlation id 0 for topics [Set(grillo)] from broker [BrokerEndPoint(1001,ba53d4fd7595,9092)] failed (kafka.client.ClientUtils$)
java.nio.channels.ClosedChannelException
at kafka.network.BlockingChannel.send(BlockingChannel.scala:110)
at kafka.producer.SyncProducer.liftedTree1$1(SyncProducer.scala:75)
at kafka.producer.SyncProducer.kafka$producer$SyncProducer$$doSend(SyncProducer.scala:74)
at kafka.producer.SyncProducer.send(SyncProducer.scala:119)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:59)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:94)
at kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:66)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
[2016-03-11 00:39:17,013] WARN [console-consumer-79688_9dd5f575d557-1457656747003-f1ed369d-leader-finder-thread], Failed to find leader for Set([grillo,0]) (kafka.consumer.ConsumerFetcherManager$LeaderFin
derThread)
kafka.common.KafkaException: fetching topic metadata for topics [Set(grillo)] from broker [ArrayBuffer(BrokerEndPoint(1001,ba53d4fd7595,9092))] failed
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:73)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:94)
at kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:66)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
Caused by: java.nio.channels.ClosedChannelException
at kafka.network.BlockingChannel.send(BlockingChannel.scala:110)
at kafka.producer.SyncProducer.liftedTree1$1(SyncProducer.scala:75)
at kafka.producer.SyncProducer.kafka$producer$SyncProducer$$doSend(SyncProducer.scala:74)
at kafka.producer.SyncProducer.send(SyncProducer.scala:119)
at kafka.client.ClientUtils$.fetchTopicMetadata(ClientUtils.scala:59)
... 3 more
and so on
In the console of the producer, I wrote some sentences:
$ docker run --rm --interactive klustera/kafka /opt/kafka_2.11-0.9.0.1/bin/kafka-console-producer.sh --topic grillo --broker-list 171.17.0.4:9092
Hola
¿Cómo estáń?
¿Todo bien?
And a few moments later, I got this response:
[2016-03-11 00:39:28,955] ERROR Error when sending message to topic grillo with key: null, value: 4 bytes with error: Failed to update metadata after 60000 ms. (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
[2016-03-11 00:40:28,956] ERROR Error when sending message to topic grillo with key: null, value: 16 bytes with error: Failed to update metadata after 60000 ms. (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
[2016-03-11 00:41:28,956] ERROR Error when sending message to topic grillo with key: null, value: 12 bytes with error: Failed to update metadata after 60000 ms. (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
And in the docker-compose logs
...
zookeeper_1 | 2016-03-11 00:39:07,072 [myid:] - INFO [ProcessThread(sid:0 cport:2181)::PrepRequestProcessor@651] - Got user-level KeeperException when processing sessionid:0x153631368b1000b type:create c
xid:0x2 zxid:0x47 txntype:-1 reqpath:n/a Error Path:/consumers Error:KeeperErrorCode = NodeExists for /consumers
zookeeper_1 | 2016-03-11 00:39:07,243 [myid:] - INFO [ProcessThread(sid:0 cport:2181)::PrepRequestProcessor@651] - Got user-level KeeperException when processing sessionid:0x153631368b1000b type:create c
xid:0x19 zxid:0x4b txntype:-1 reqpath:n/a Error Path:/consumers/console-consumer-79688/owners/grillo Error:KeeperErrorCode = NoNode for /consumers/console-consumer-79688/owners/grillo
zookeeper_1 | 2016-03-11 00:39:07,247 [myid:] - INFO [ProcessThread(sid:0 cport:2181)::PrepRequestProcessor@651] - Got user-level KeeperException when processing sessionid:0x153631368b1000b type:create $xid:0x1a zxid:0x4c txntype:-1 reqpath:n/a Error Path:/consumers/console-consumer-79688/owners Error:KeeperErrorCode = NoNode for /consumers/console-consumer-79688/owners
...
UPDATE 2
I made it work, at least, in docker-machine:
First, I defined a variable with the name of the docker-machine:
DOCKER_VM=kafka_test
Then, I modify the docker-compose.yml as follows:
KAFKA_ADVERTISED_HOST_NAME: "${DOCKER_MACHINE_IP}"
Lastly, in the environment of the docker-machine, I execute:
DOCKER_MACHINE_IP=$(docker-machine ip $DOCKER_VM) docker-compose up -d
But in the laptop (I mean, without using a virtual machine, it doesn't work)
Answer
My solution to this issue is slightly different. I configure Kafka to advertise on kafka host and, because it's exposed on the host machine on localhost:9092, I add an entry in /etc/hosts for kafka to resolve to localhost. By doing this Kafka can be accessed from both other Docker containers and from localhost.
docker-compose.yml:
my-web-service:
build: ./my-web-service
ports:
- "8000:8000"
links:
- kafka
kafka:
image: "wurstmeister/kafka:0.10.2.0"
ports:
- "9092:9092"
hostname: kafka
links:
- zookeeper
environment:
- KAFKA_ADVERTISED_HOST_NAME=kafka
- KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181
- KAFKA_ADVERTISED_PORT=9092
zookeeper:
image: wurstmeister/zookeeper
ports:
- "2181:2181"
Updated hosts file:
more /etc/hosts
127.0.0.1 localhost kafka