NoClassDefFoundError: io/questdb/client/Sender about kafka-questdb-connector

[jerrinot]

Hello, @iamkucuk, this indicates questdb JAR is missing on Kafka Connect classpath. The ZIP with connector contains 2 JARs:

1. the connect itself
2. questdb jar - this is a dependency of the connector

The stracktrace shows Kafka Connect does not see #2.

[iamkucuk]

Hello @jerrinot Thanks for the fast response! I created a docker file that is very close to the one within the repo. Here it is:

FROM ubuntu:latest AS builder
WORKDIR /opt
RUN apt-get update && apt-get install -y curl wget unzip jq
RUN curl -s https://api.github.com/repos/questdb/kafka-questdb-connector/releases/latest | jq -r '.assets[]|select(.content_type == "application/zip")|.browser_download_url'|wget -qi -
RUN unzip kafka-questdb-connector-*-bin.zip

FROM confluentinc/cp-kafka-connect:7.2.2

COPY --from=builder /opt/kafka-questdb-connector/*.jar /connector/
ENV CONNECT_PLUGIN_PATH=/connector/
USER 1001

What am I missing here?

[iamkucuk]

Apparently CONNECT_PLUGIN_PATH is having you install the plugin, but does not make the code reachable. Using as suggested fixed the specific issue.

Here is the example:
COPY --from=builder /opt/kafka-questdb-connector/*.jar /kafka/connect/questdb-connector/