Dockerfile for Apache Kafka
The image is available directly from https://registry.hub.docker.com/
##Pre-Requisites
- install docker-compose https://docs.docker.com/compose/install/
- modify the
KAFKA_ADVERTISED_HOST_NAME
indocker-compose.yml
to match your docker host IP (Note: Do not use localhost or 127.0.0.1 as the host ip if you want to run multiple brokers.) - if you want to customise any Kafka parameters, simply add them as environment variables in
docker-compose.yml
, e.g. in order to increase themessage.max.bytes
parameter set the environment toKAFKA_MESSAGE_MAX_BYTES: 2000000
. To turn off automatic topic creation setKAFKA_AUTO_CREATE_TOPICS_ENABLE: 'false'
##Usage
Start a cluster:
docker-compose up -d
Add more brokers:
docker-compose scale kafka=3
Destroy a cluster:
docker-compose stop
##Note
The default docker-compose.yml
should be seen as a starting point. By default each broker will get a new port number and broker id on restart. Depending on your use case this might not be desirable. If you need to use specific ports and broker ids, modify the docker-compose configuration accordingly, e.g. docker-compose-single-broker.yml:
docker-compose -f docker-compose-single-broker.yml up
##Broker IDs
If you don't specify a broker id in your docker-compose file, it will automatically be generated (see https://issues.apache.org/jira/browse/KAFKA-1070. This allows scaling up and down. In this case it is recommended to use the --no-recreate
option of docker-compose to ensure that containers are not re-created and thus keep their names and ids.
##Automatically create topics
If you want to have kafka-docker automatically create topics in Kafka during
creation, a KAFKA_CREATE_TOPICS
environment variable can be
added in docker-compose.yml
.
Here is an example snippet from docker-compose.yml
:
environment:
KAFKA_CREATE_TOPICS: "Topic1:1:3,Topic2:1:1"
Topic 1
will have 1 partition and 3 replicas, Topic 2
will have 1 partition and 1 replica.
##Advertised hostname
You can configure the advertised hostname in different ways
- explicitly, using
KAFKA_ADVERTISED_HOST_NAME
- via a command, using
HOSTNAME_COMMAND
, e.g.HOSTNAME_COMMAND: "route -n | awk '/UG[ \t]/{print $$2}'"
When using commands, make sure you review the "Variable Substitution" section in https://docs.docker.com/compose/compose-file/
If KAFKA_ADVERTISED_HOST_NAME
is specified, it takes presendence over HOSTNAME_COMMAND
For AWS deployment, you can use the Metadata service to get the container host's IP:
HOSTNAME_COMMAND=wget -t3 -T2 -qO- http://169.254.169.254/latest/meta-data/local-ipv4
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html
##Tutorial