kd : kafka on docker for testing purpose

Just follow these steps to setup a kafka cluster and kafka-manager running in containers.

requirements

• user needs to be in the docker system group (or to be root)
• docker >= 1.12
• docker-compose >= 1.8 (because of version 2 syntax in yaml compose file)

tip to get the latest release of docker-compose

using python-pip tool :

pip install --upgrade docker-compose

clone repository

git clone git@github.com:ledroide/kd.git

run a Kafka cluster including multiple nodes + zookeeper + kafka-manager

• pwd near the compose file

cd kd

• check and pull the docker images :

docker-compose build --pull

• launch instances :

docker-compose up -d 

• scale up to 4 kafka nodes (until the compose file does not support any scale directive) :

export KAFKANODES=4
docker-compose scale kafka=${KAFKANODES}

create some random topics

• install pwgen (here with ubuntu yakkety yak ; if older version use apt-get instead, if redhat use yum) :

[ -x /usr/bin/pwgen ] && echo "Already installed" || ( apt update && apt install pwgen )

we hijack the password generator for creating topic names.

• create random topics with some random parameters :

NAMELENGHT=10
export NBTOPIC=100
for TopicID in $(/usr/bin/pwgen -AB10 ${NAMELENGHT} ${NBTOPIC}) 
  do docker-compose run kafka /opt/kafka/bin/kafka-topics.sh --create \
   --zookeeper zookeeper:2181 \
   --replication-factor $((RANDOM%(${KAFKANODES}-1)+2)) \
   --partitions $((RANDOM%(${KAFKANODES}-1)+2)) \
   --topic ${TopicID}
done

use producers and consumers

• store locally the topics list :

docker-compose run kafka /opt/kafka/bin/kafka-topics.sh \
 --zookeeper zookeeper:2181 --list > /tmp/alltopics
echo "Number of topics in the cluster : $(wc -l /tmp/alltopics | cut -d ' '  -f 1)"

• pick up a topic from the list, store it in a file and in a variable

/bin/sed "$((RANDOM%(${NBTOPIC})+1))q;d" /tmp/alltopics  > /tmp/onetopic && \
 export AVGTOPIC=$(/bin/cat /tmp/onetopic) && \
 export CLEANTOPIC="${AVGTOPIC//[$'\t\r\n ']}" ; \
 echo "Current random topic is $CLEANTOPIC"

• start a console as an interactive producer to the random topic :

docker-compose run --name "pub_${CLEANTOPIC}" --rm kafka \
 kafka-console-producer.sh --broker-list kafka:9092 --topic ${CLEANTOPIC}

• and another console with a consumer console :

export AVGTOPIC=$(/bin/cat /tmp/onetopic) && \
 export CLEANTOPIC="${AVGTOPIC//[$'\t\r\n ']}" ; \ 
 echo "Current random topic is $CLEANTOPIC"
docker-compose run --name sub_${CLEANTOPIC} --rm kafka \
 kafka-console-consumer.sh --zookeeper zookeeper:2181 \
 --from-beginning --topic ${CLEANTOPIC}

Kafka Manager interface

• open the manager interface in you browser : http://localhost:9000/addCluster
• add a new cluster
  • Cluster name : whatever
  • Cluster Zookeeper hosts : zookeeper:2181
  • enable JMX polling
• select the new cluster and play

performance testing

• tip to generate multiple messages to a broker as a producer, just like a basic lorem ipsum :

tr -dc a-z1-4 </dev/urandom | tr 1-2 ' \n' | awk 'length==0 || length>50' | tr 3-4 ' ' | sed 's/^ *//' | cat -s | sed 's/ / /g' | fmt