Awesome

Kafdrop

Kafdrop is a UI for monitoring Apache Kafka clusters. The tool displays information such as brokers, topics, partitions, and even lets you view messages. It is a light weight application that runs on Spring Boot and requires very little configuration.

Requirements

Java 8
Kafka 2.0 or later (might work with earlier versions)
Zookeeper (3.4.5 or later)

Optional, additional integration:

Schema Registry

Building

After cloning the repository, building should just be a matter of running a standard Maven build:

$ mvn clean package

Running Stand Alone

The build process creates an executable JAR file.

java -jar ./target/kafdrop-<version>.jar --zookeeper.connect=<host:port>,<host:port>,... --kafka.brokers=<host:port>,<host:port>,...

Then open a browser and navigate to http://localhost:9000. The port can be overridden by adding the following config:

    --server.port=<port>

Additionally, you can optionally configure a schema registry connection with:

    --schemaregistry.connect=http://localhost:8081

Finally, a default message format (e.g. to deserialize Avro messages) can optionally be configured as follows:

    --message.format=AVRO

Valid format values are "DEFAULT" and "AVRO". This setting can also be configured at the topic level via dropdown when viewing messages.

Running with Docker

Note for Mac Users: You need to convert newline formatting of the kafdrop.sh file before running this command:

    dos2unix src/main/docker/*

The following maven command will generate a Docker image:

    mvn clean package assembly:single docker:build

Once the build finishes you can launch the image as follows:

    docker run -d -p 9000:9000 -e ZOOKEEPER_CONNECT=<host:port,host:port> kafdrop

And access the UI at http://localhost:9000.

Configuration Options

Option	Default	Description
kafka.truststoreLocation		Location of the truststore used for secure connections
kafka.keystoreLocation		Location of the keystore used for secure connections
kafka.additionalProperties.<property>		Additional properties to pass to the Admin or Consumer clients
kafka.adminPool.minIdle	0	Minimum number of unused admin clients to keep open
kafka.adminPool.maxIdle	8	Maximum number of unused admin clients to keep open
kafka.adminPool.maxTotal	8	Maximum number of admin clients to have open at one time
kafka.adminPool.maxWaitMillis	-1	Milliseconds to wait for an admin client from the pool (-1 == forever)
kafka.consumerPool.minIdle	0	Minimum number of unused consumer clients to keep open
kafka.consumerPool.maxIdle	8	Maximum number of unused consumer clients to keep open
kafka.consumerPool.maxTotal	8	Maximum number of consumer clients to have open at one time
kafka.consumerPool.maxWaitMillis	-1	Millis to wait for a consumer client from the pool (-1 == forever)

Kafka APIs

Starting with version 2.0.0, Kafdrop offers a set of Kafka APIs that mirror the existing HTML views. Any existing endpoint can be returned as JSON by simply setting the Accept : application/json header. There are also two endpoints that are JSON only:

/topic : Returns array of all topic names
/topic/{topicName}/{consumerId} : Return partition offset and lag details for a specific topic and consumer.

Swagger

To help document the Kafka APIs, Swagger has been included. The Swagger output is available by default at the following Kafdrop URL:

/v2/api-docs

However this can be overridden with the following configuration:

springfox.documentation.swagger.v2.path=/new/swagger/path

Currently only the JSON endpoints are included in the Swagger output; the HTML views and Spring Boot debug endpoints are excluded.

You can disable Swagger output with the following configuration:

swagger.enabled=false

CORS Headers

Starting in version 2.0.0, Kafdrop sets CORS headers for all endpoints. You can control the CORS header values with the following configurations:

cors.allowOrigins (default is *)
cors.allowMethods (default is GET,POST,PUT,DELETE)
cors.maxAge (default is 3600)
cors.allowCredentials (default is true)
cors.allowHeaders (default is Origin,Accept,X-Requested-With,Content-Type,Access-Control-Request-Method,Access-Control-Request-Headers,Authorization)

You can also disable CORS entirely with the following configuration:

cors.enabled=false