when you use kafka(in docker container), Where exactly is the plugin path? - apache-kafka

Question

----- i use kafka, kafka-connect(image: confluentinc/cp-kafka-connect)
when you use kafka in docker container if you wanna operate kafka, you have to go into the container(like 'docker exec -it kafka' or 'docker exec -it kafka-connect' ----> this is another question what i wanna ask) , right..??
i tried putting some connector (jdbc connector, mysql connector) into kafka-connect container, but it didn't work.
so.. my question is
after docker-compose up(put in container), if i wanna connect with some connectors('./bin/connect-distributed.sh ./etc/kafka/connect-distributed.properties'),
what container i have to go into???
if i type plugin path, where should i write?( kafka? kafka-connect?)
I wouldn't mind if it was difficult to read... sorry for that

Answer 1

No, you don't need to exec anywhere unless you cannot download Kafka on your host machine to get the CLI scripts. But you'd only exec for kafka-topics, console producer/consumer, kafka-consumer-groups, etc, not any of the Connect scripts.
The Connect container automatically runs the Distributed script and you simply provide CONNECT_PLUGIN_PATH as an environment variable to any directory in the container you want to use for the plugins (I like /opt/connectors if I mount volume, but that's not where confluent-hub installs to for that image). That variable doesn't do anything for the broker image, only Connect.
Related How to install connectors to the docker image of apache kafka connect

Answer 2

If your requirement is startup a Kafka Connect.
You can use the basic guide published by Confluent "Build Your Own Apache Kafka® Demos"
Basically you need execute the following instructions:
git clone https://github.com/confluentinc/cp-all-in-one.git
cd cp-all-in-one/cp-all-in-one
git checkout 7.1.1-post
docker-compose up -d
This has Control Center at http://localhost:8088
If you need install a Connector, you can go to the https://www.confluent.io/hub select your specific connector.
Then, you can create your DockerImage of specific Kafka Connect server.
1.- Write a Dockerfile.
vim Dockerfile
2.- Add connector "example JDBC" from Confluent Hub.
FROM confluentinc/cp-kafka-connect
ENV MYSQL_DRIVER_VERSION 5.1.39
RUN confluent-hub install --no-prompt confluentinc/kafka-connect-jdbc:10.5.0
RUN curl -k -SL "https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-${MYSQL_DRIVER_VERSION}.tar.gz" \
| tar -xzf - -C /usr/share/confluent-hub-components/confluentinc-kafka-connect-jdbc/lib \
--strip-components=1 mysql-connector-java-5.1.39/mysql-connector-java-${MYSQL_DRIVER_VERSION}-bin.jar
3.- Build the docker image.
docker build . -t my-kafka-connect-jdbc:1.0.0
4.- Then, you can go to edit your docker-compose.yml, change the line 57
from:
image: cnfldemos/cp-server-connect-datagen:0.5.3-7.1.0
to:
image: my-kafka-connect-jdbc:1.0.0
5.- Finally, stop and start your Confluent Platform local environment:
docker-compose down
docker-compose up
Verify your docker
docker ps
Test your Connect server:
curl --location --request GET 'http://localhost:8083/connectors'