AKHQ (previously known as KafkaHQ)

Kafka GUI for Apache Kafka to manage topics, topics data, consumers group, schema registry, connect and more...

Contents

• Features
• Quick Preview
• Installation
  • Docker
  • Stand Alone
  • Kubernetes using Helm
• Configuration
  • JVM.options file
  • Kafka cluster
  • AKHQ
  • AKHQ Configuration Bootstrap OAuth2
  • Security
  • Server
  • Micronaut
• Api
• Monitoring Endpoint
• Development Environment
• Schema references
• Who's using AKHQ

Features

• General
  • Works with modern Kafka cluster (1.0+)
  • Connection on standard or ssl, sasl cluster
  • Multi cluster
• Topics
  • List
  • Configurations view
  • Partitions view
  • ACLS view
  • Consumer groups assignments view
  • Node leader & assignments view
  • Create a topic
  • Configure a topic
  • Delete a topic
• Browse Topic data
  • View data, offset, key, timestamp & headers
  • Automatic deserialization of avro message encoded with schema registry
  • Configurations view
  • Logs view
  • Delete a record
  • Empty a Topic (Delete all the record from one topic)
  • Sort view
  • Filter per partitions
  • Filter with a starting time
  • Filter data with a search string
• Consumer Groups (only with kafka internal storage, not with the old Zookeeper one)
  • List with lag, topics assignments
  • Partitions view & lag
  • ACLS view
  • Node leader & assignments view
  • Display active and pending consumers groups
  • Delete a consumer group
  • Update consumer group offsets to start / end / timestamp
• Schema Registry
  • List schema
  • Create / Update / Delete a schema
  • View and delete individual schema version
• Connect
  • List connect definition
  • Create / Update / Delete a definition
  • Pause / Resume / Restart a definition or a task
• Nodes
  • List
  • Configurations view
  • Logs view
  • Configure a node
• ACLS
  • List principals
  • List principals topic & group acls
• Authentication and Roles
  • Read only mode
  • BasicHttp with roles per user
  • User groups configuration
  • Filter topics with regexp for current groups
  • Ldap configuration to match AKHQ groups/roles
  • Filter consumer groups with regexp for current groups

New React UI

Since this is a major rework, the new UI can have some issues, so please report any issue, thanks!

Quick preview

• Download docker-compose.yml file
• run docker-compose pull to be sure to have the last version of AKHQ
• run docker-compose up
• go to http://localhost:8080

It will start a Kafka node, a Zookeeper node, a Schema Registry, a Kafka Connect, fill with some sample data, start a consumer group and a kafka stream & start AKHQ.

Installation

First you need a configuration files in order to configure AKHQ connections to Kafka Brokers.

Docker

docker run -d \
    -p 8080:8080 \
    -v /tmp/application.yml:/app/application.yml \
    tchiotludo/akhq

• With -v /tmp/application.yml must be an absolute path to configuration file
• Go to http://localhost:8080

Stand Alone

• Install Java 11
• Download the latest jar on release page
• Create an configuration files
• Launch the application with java -Dmicronaut.config.files=/path/to/application.yml -jar akhq.jar
• Go to http://localhost:8080

Running in Kubernetes (using a Helm Chart)

Using Helm repository

• Add the AKHQ helm charts repository:

helm repo add akhq https://akhq.io/

• Install or upgrade

helm upgrade --install akhq akhq/akhq

Requirements

• Chart version >=0.1.1 requires Kubernetes version >=1.14
• Chart version 0.1.0 works on previous Kubernetes versions

helm install akhq akhq/akhq --version 0.1.0

Using git

• Clone the repository:

git clone https://github.com/tchiotludo/akhq && cd akhq/helm/akhq

• Update helm values located in values.yaml
  • configuration values will contains all related configuration that you can find in application.example.yml and will be store in a ConfigMap
  • secrets values will contains all sensitive configurations (with credentials) that you can find in application.example.yml and will be store in Secret
  • Both values will be merged at startup
• Apply the chart:

helm install --name=akhq-release-name  .

Configuration

Configuration file can by default be provided in either Java properties, YAML, JSON or Groovy files. YML Configuration file example can be found here :application.example.yml

Pass custom Java opts

By default, the docker container will allow a custom JVM options setting the environments vars JAVA_OPTS. For example, if you want to change the default timezone, just add -e "JAVA_OPTS=-Duser.timezone=Europe/Paris"

Run with another jvm.options file

By default, the docker container will run with a jvm.options file, you can override it with your own with an Environment Variable. With the JVM_OPTS_FILE environment variable, you can override the jvm.options file by passing the path of your file instead.

Override the JVM_OPTS_FILE with docker run:

docker run -d \
    --env JVM_OPTS_FILE={{path-of-your-jvm.options-file}}
    -p 8080:8080 \
    -v /tmp/application.yml:/app/application.yml \
    tchiotludo/akhq

Override the JVM_OPTS_FILE with docker-compose:

version: '3.7'
services:
  akhq:
    image: tchiotludo/akhq-jvm:dev
    environment:
      JVM_OPTS_FILE: /app/jvm.options
    ports:
      - "8080:8080"
    volumes:
      - /tmp/application.yml:/app/application.yml

If you do not override the JVM_OPTS_FILE, the docker container will take the defaults one instead.

Kafka cluster configuration

• akhq.connections is a key value configuration with :
  • key: must be an url friendly (letter, number, _, -, ... dot are not allowed here) string to identify your cluster (my-cluster-1 and my-cluster-2 is the example above)
  • properties: all the configurations found on Kafka consumer documentation. Most important is bootstrap.servers that is a list of host:port of your Kafka brokers.
  • schema-registry: (optional)
    • url: the schema registry url
    • type: the type of schema registry used, either 'confluent' or 'tibco'
    • basic-auth-username: schema registry basic auth username
    • basic-auth-password: schema registry basic auth password
    • properties: all the configurations for registry client, especially ssl configuration
  • connect: (optional list, define each connector as an element of a list)
    • name: connect name
    • url: connect url
    • basic-auth-username: connect basic auth username
    • basic-auth-password: connect basic auth password
    • ssl-trust-store: /app/truststore.jks
    • ssl-trust-store-password: trust-store-password
    • ssl-key-store: /app/truststore.jks
    • ssl-key-store-password: key-store-password

SSL Kafka Cluster with basic auth

Configuration example for kafka cluster secured by ssl for saas provider like aiven (full https & basic auth):

You need to generate a jks & p12 file from pem, cert files give by saas provider.

openssl pkcs12 -export -inkey service.key -in service.cert -out client.keystore.p12 -name service_key
keytool -import -file ca.pem -alias CA -keystore client.truststore.jks

Configurations will look like this example:

akhq:
  connections:
    ssl-dev:
      properties:
        bootstrap.servers: "{{host}}.aivencloud.com:12835"
        security.protocol: SSL
        ssl.truststore.location: {{path}}/avnadmin.truststore.jks
        ssl.truststore.password: {{password}}
        ssl.keystore.type: "PKCS12"
        ssl.keystore.location: {{path}}/avnadmin.keystore.p12
        ssl.keystore.password: {{password}}
        ssl.key.password: {{password}}
      schema-registry:
        url: "https://{{host}}.aivencloud.com:12838"
        type: "confluent"
        basic-auth-username: avnadmin
        basic-auth-password: {{password}}
        properties:
          schema.registry.ssl.truststore.location: {{path}}/avnadmin.truststore.jks
          schema.registry.ssl.truststore.password: {{password}}
      connect:
        - name: connect-1
          url: "https://{{host}}.aivencloud.com:{{port}}"
          basic-auth-username: avnadmin
          basic-auth-password: {{password}}

AKHQ configuration

Pagination

• akhq.pagination.page-size number of topics per page (default : 25)

Topic List

• akhq.topic.internal-regexps is list of regexp to be considered as internal (internal topic can't be deleted or updated)
• akhq.topic.stream-regexps is list of regexp to be considered as internal stream topic

Topic creation default values

These parameters are the default values used in the topic creation page.

• akhq.topic.replication Default number of replica to use
• akhq.topic.partition Default number of partition

Topic Data

• akhq.topic-data.sort: default sort order (OLDEST, NEWEST) (default: OLDEST)
• akhq.topic-data.size: max record per page (default: 50)
• akhq.topic-data.poll-timeout: The time, in milliseconds, spent waiting in poll if data is not available in the buffer (default: 1000).

Ui Settings

Topics

• akhq.ui-options.topic.default-view is default list view (ALL, HIDE_INTERNAL, HIDE_INTERNAL_STREAM, HIDE_STREAM) (default: HIDE_INTERNAL)
• akhq.ui-options.topic.skip-consumer-groups hide consumer groups columns on topic list
• akhq.ui-options.topic.skip-last-record hide the last records on topic list

Topic Data

• akhq.ui-options.topic-data.sort: default sort order (OLDEST, NEWEST) (default: OLDEST)

Protobuf deserialization

To deserialize topics containing data in Protobuf format, you can set topics mapping: for each topic-regex you can specify descriptor-file-base64 (descriptor file encoded to Base64 format), or you can put descriptor files in descriptors-folder and specify descriptor-file name, also specify corresponding message types for keys and values. If, for example, keys are not in Protobuf format, key-message-type can be omitted, the same for value-message-type. This configuration can be specified for each Kafka cluster.

Example configuration can look like as follows:

akhq:
  connections:
    kafka:
      properties:
        # standard kafka properties
      deserialization:
        protobuf:
          descriptors-folder: "/app/protobuf_desc"
          topics-mapping:
            - topic-regex: "album.*"
              descriptor-file-base64: "Cs4BCgthbGJ1bS5wcm90bxIXY29tLm5ldGNyYWNrZXIucHJvdG9idWYidwoFQWxidW0SFAoFdGl0bGUYASABKAlSBXRpdGxlEhYKBmFydGlzdBgCIAMoCVIGYXJ0aXN0EiEKDHJlbGVhc2VfeWVhchgDIAEoBVILcmVsZWFzZVllYXISHQoKc29uZ190aXRsZRgEIAMoCVIJc29uZ1RpdGxlQiUKF2NvbS5uZXRjcmFja2VyLnByb3RvYnVmQgpBbGJ1bVByb3RvYgZwcm90bzM="
              value-message-type: "Album"
            - topic-regex: "film.*"
              descriptor-file-base64: "CuEBCgpmaWxtLnByb3RvEhRjb20uY29tcGFueS5wcm90b2J1ZiKRAQoERmlsbRISCgRuYW1lGAEgASgJUgRuYW1lEhoKCHByb2R1Y2VyGAIgASgJUghwcm9kdWNlchIhCgxyZWxlYXNlX3llYXIYAyABKAVSC3JlbGVhc2VZZWFyEhoKCGR1cmF0aW9uGAQgASgFUghkdXJhdGlvbhIaCghzdGFycmluZxgFIAMoCVIIc3RhcnJpbmdCIQoUY29tLmNvbXBhbnkucHJvdG9idWZCCUZpbG1Qcm90b2IGcHJvdG8z"
              value-message-type: "Film"
            - topic-regex: "test.*"
              descriptor-file: "other.desc"
              key-message-type: "Row"
              value-message-type: "Envelope"

More examples about Protobuf deserialization can be found in tests. Info about the descriptor files generation can be found in test resources.

AKHQ Configuration Bootstrap OAuth2

Requirement Library Strimzi

The kafka brokers must be configured with the Strimzi library and an OAuth2 provider (Keycloak example).

This contains documentation and examples.

Configuration Bootstrap

It's not necessary to compile AKHQ to integrate the Strimzi libraries since the libs will be included on the final image !

You must configure AKHQ through the application.yml file.

akhq:
  connections:
    my-kafka-cluster:
      properties:
        bootstrap.servers: "<url broker kafka>:9094,<url broker kafka>:9094"
        sasl.jaas.config: org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginModule required auth.valid.issuer.uri="https://<url keycloak>/auth/realms/sandbox_kafka" oauth.jwks.endpoint.uri="https:/<url keycloak>//auth/realms/sandbox_kafka/protocol/openid-connect/certs" oauth.username.claim="preferred_username" oauth.client.id="kafka-producer-client" oauth.client.secret="" oauth.ssl.truststore.location="kafka.server.truststore.jks" oauth.ssl.truststore.password="xxxxx" oauth.ssl.truststore.type="jks" oauth.ssl.endpoint_identification_algorithm="" oauth.token.endpoint.uri="https:///auth/realms/sandbox_kafka/protocol/openid-connect/token";
        sasl.login.callback.handler.class: io.strimzi.kafka.oauth.client.JaasClientOauthLoginCallbackHandler
        security.protocol: SASL_PLAINTEXT
        sasl.mechanism: OAUTHBEARER

I put oauth.ssl.endpoint_identification_algorithm = "" for testing or my certificates did not match the FQDN. In a production, you have to remove it.

Security

• akhq.security.default-group: Default group for all the user even unlogged user. By default, the default group is admin and allow you all read / write access on the whole app.

By default, security & roles is disabled and anonymous user have full access, i.e. micronaut.security.enabled: false. To enable security & roles set micronaut.security.enabled: true and configure desired type of authentication (basic auth, LDAP, etc.).

If you need a read-only application, simply add this to your configuration files :

akhq:
  security:
    default-group: reader

Auth

JWT

AKHQ uses JWT tokens to perform authentication. Please generate a secret that is at least 256 bits and change the config like this:

micronaut:
  security:
    enabled: true
    token:
      jwt:
        signatures:
          secret:
            generator:
              secret: <Your secret here>

Groups

Groups allow you to limit user

Define groups with specific roles for your users

• akhq.security.default-group: Default group for all the user even unlogged user

• akhq.security.groups: Groups map definition

  • key: a uniq key used as name if not specified
    • name: group-name Group identifier
    • roles: Roles list for the group
    • attributes.topics-filter-regexp: Regexp list to filter topics available for current group
    • attributes.connects-filter-regexp: Regexp list to filter Connect tasks available for current group
    • attributes.consumer-groups-filter-regexp: Regexp list to filter Consumer Groups available for current group

3 defaults group are available :

• admin with all right
• reader with only read access on all AKHQ
• no-roles without any roles, that force user to login

Basic Auth

• akhq.security.basic-auth: List user & password with affected roles
  • - username: actual-username: Login of the current user as a yaml key (maybe anything email, login, ...)
    • password: Password in sha256 (default) or bcrypt. The password can be converted
      • For default SHA256, with command echo -n "password" | sha256sum or Ansible filter {{ 'password' | hash('sha256') }}
      • For BCrypt, with Ansible filter {{ 'password' | password_hash('blowfish') }}
    • passwordHash: Password hashing algorithm, either SHA256 or BCRYPT
    • groups: Groups for current user

Take care that basic auth will use session store in the server memory. If your instance is behind a reverse proxy or a loadbalancer, you will need to forward the session cookie named SESSION and / or use session stickiness

Configure basic-auth connection in AKHQ

micronaut:
  security:
    enabled: true
akhq.security:
  basic-auth:
    - username: admin
      password: "$2a$<hashed password>"
      passwordHash: BCRYPT
      groups: 
      - admin
    - username: reader
      password: "<SHA-256 hashed password>"
      groups: 
      - reader

LDAP

Configure how the ldap groups will be matched in AKHQ groups

• akhq.security.ldap.groups: Ldap groups list
  • - name: ldap-group-name: Ldap group name (same name as in ldap)
    • groups: AKHQ group list to be used for current ldap group

Example using online ldap test server

Configure ldap connection in micronaut

micronaut:
  security:
    enabled: true
    ldap:
      default:
        enabled: true
        context:
          server: 'ldap://ldap.forumsys.com:389'
          managerDn: 'cn=read-only-admin,dc=example,dc=com'
          managerPassword: 'password'
        search:
          base: "dc=example,dc=com"
        groups:
          enabled: true
          base: "dc=example,dc=com"

If you want to enable anonymous auth to your LDAP server you can pass :

managerDn: ''
managerPassword: ''

In Case your LDAP groups do not use the default UID for group membership, you can solve this using

micronaut:
  security:
    enabled: true
    ldap:
      default:
        search:
          base: "OU=UserOU,dc=example,dc=com"
          attributes:
            - "cn"
        groups:
          enabled: true
          base: "OU=GroupsOU,dc=example,dc=com"
          filter: "member={0}"

Replace

attributes:
  - "cn"

with your group membership attribute

Configure AKHQ groups and Ldap groups and users

micronaut:
  security:
    enabled: true
akhq:
  security:
    groups:
      topic-reader:
        name: topic-reader # Group name
        roles:  # roles for the group
          - topic/read
        attributes:
          # List of Regexp to filter topic available for group
          # Single line String also allowed
          # topics-filter-regexp: "^(projectA_topic|projectB_.*)$"
          topics-filter-regexp:
            - "^projectA_topic$" # Individual topic
            - "^projectB_.*$" # Topic group
          connects-filter-regexp: 
            - "^test.*$"
          consumer-groups-filter-regexp: 
            - "consumer.*"
      topic-writer:
        name: topic-writer # Group name
        roles:
          - topic/read
          - topic/insert
          - topic/delete
          - topic/config/update
        attributes:
          topics-filter-regexp: 
            - "test.*"
          connects-filter-regexp:
            - "^test.*$"
          consumer-groups-filter-regexp:
            - "consumer.*"
    ldap:
      groups:
        - name: mathematicians
          groups:
            - topic-reader
        - name: scientists
          groups:
            - topic-reader
            - topic-writer
      users:
        - username: franz
          groups:
            - topic-reader
            - topic-writer

OIDC

To enable OIDC in the application, you'll first have to enable OIDC in micronaut:

micronaut:
  security:
    oauth2:
      enabled: true
      clients:
        google:
          client-id: "<client-id>"
          client-secret: "<client-secret>"
          openid:
            issuer: "<issuer-url>"

To further tell AKHQ to display OIDC options on the login page and customize claim mapping, configure OIDC in the AKHQ config:

akhq:
  security:
    oidc:
      enabled: true
      providers:
        google:
          label: "Login with Google"
          username-field: preferred_username
          # specifies the field name in the oidc claim containing the use assigned role (eg. in keycloak this would be the Token Claim Name you set in your Client Role Mapper)
          groups-field: roles
          default-group: topic-reader
          groups:
            # the name of the user role set in your oidc provider and associated with your user (eg. in keycloak this would be a client role)
            - name: mathematicians
              groups:
                # the corresponding akhq groups (eg. topic-reader/writer or akhq default groups like admin/reader/no-role)
                - topic-reader
            - name: scientists
              groups:
                - topic-reader
                - topic-writer
          users:
            - username: franz
              groups:
                - topic-reader
                - topic-writer

The username field can be any string field, the roles field has to be a JSON array.

Debugging authentication

Debugging auth can be done by increasing log level on Micronaut that handle most of the authentication part :

curl -i -X POST -H "Content-Type: application/json" \
       -d '{ "configuredLevel": "TRACE" }' \
       http://localhost:8081/loggers/io.micronaut.security
       
       
curl -i -X POST -H "Content-Type: application/json" \
       -d '{ "configuredLevel": "TRACE" }' \
       http://localhost:8081/loggers/org.akhq.configs

Server

• micronaut.server.context-path: if behind a reverse proxy, path to akhq with trailing slash (optional). Example: akhq is behind a reverse proxy with url http://my-server/akhq, set base-path: "/akhq/". Not needed if you're behind a reverse proxy with subdomain http://akhq.my-server/

Kafka admin / producer / consumer default properties

• akhq.clients-defaults.{{admin|producer|consumer}}.properties: default configuration for admin producer or consumer. All properties from Kafka documentation is available.

Micronaut configuration

Since AKHQ is based on Micronaut, you can customize configurations (server port, ssl, ...) with Micronaut configuration. More information can be found on Micronaut documentation

Docker

The AKHQ docker image supports 4 environment variables to handle configuration :

• AKHQ_CONFIGURATION: a string that contains the full configuration in yml that will be written on /app/configuration.yml on the container.
• MICRONAUT_APPLICATION_JSON: a string that contains the full configuration in JSON format
• MICRONAUT_CONFIG_FILES: a path to a configuration file in the container. Default path is /app/application.yml
• CLASSPATH: additional Java classpath entries. Must be used to specify the location of the TIBCO Avro client library jar if a 'tibco' schema registry type is used

How to mount configuration file

Take care when you mount configuration files to not remove akhq files located on /app. You need to explicitly mount the /app/application.yml and not mount the /app directory. This will remove the AKHQ binaries and give you this error: /usr/local/bin/docker-entrypoint.sh: 9: exec: ./akhq: not found

volumeMounts:
- mountPath: /app/application.yml
  subPath: application.yml
  name: config
  readOnly: true

Using the TIBCO schema registry

If you are using the TIBCO schema registry, you will also need to mount and use the TIBCO Avro client library and its dependencies. The akhq service in a docker compose file might look something like:

  akhq:
    # build:
    #   context: .
    image: tchiotludo/akhq
    volumes:
      - /opt/tibco/akd/repo/1.2/lib/tibftl-kafka-avro-1.2.0-thin.jar:/app/tibftl-kafka-avro-1.2.0-thin.jar
      - /opt/tibco/akd/repo/1.2/lib/deps:/app/deps
    environment:
      AKHQ_CONFIGURATION: |
        akhq:
          connections:
            docker-kafka-server:
              properties:
                bootstrap.servers: "kafka:9092"
              schema-registry:
                type: "tibco"
                url: "http://repo:8081"
              connect:
                - name: "connect"
                  url: "http://connect:8083"
      CLASSPATH: "/app/tibftl-kafka-avro-1.2.0-thin.jar:/app/deps/*"
    ports:
      - 8080:8080
    links:
      - kafka
      - repo

Api

An experimental api is available that allow you to fetch all the exposed on AKHQ through api.

Take care that this api is experimental and will change in a future release. Some endpoints expose too many data and is slow to fetch, and we will remove some properties in a future in order to be fast.

Example: List topic endpoint expose log dir, consumer groups, offsets. Fetching all theses is slow for now, and we will remove these in a future.

You can discover the api endpoint here :

• /api: a RapiDoc webpage that document all the endpoints.
• /swagger/akhq.yml: a full OpenApi specifications files

Monitoring endpoint

Several monitoring endpoint is enabled by default and available on port 8081 only.

You can disable it, change the port or restrict access only for authenticated users following micronaut configuration below.

• /info Info Endpoint with git status information.
• /health Health Endpoint
• /loggers Loggers Endpoint
• /metrics Metrics Endpoint
• /prometheus Prometheus Endpoint

Debugging AKHQ performance issues

You can debug all query duration from AKHQ with this commands

curl -i -X POST -H "Content-Type: application/json" \
       -d '{ "configuredLevel": "TRACE" }' \
       http://localhost:8081/loggers/org.akhq

Development Environment

Early dev image

You can have access to last feature / bug fix with docker dev image automatically build on tag dev

docker pull tchiotludo/akhq:dev

The dev jar is not publish on GitHub, you have 2 solutions to have the dev jar :

Get it from docker image

docker pull tchiotludo/akhq:dev
docker run --rm --name=akhq -it tchiotludo/akhq:dev
docker cp akhq:/app/akhq.jar .

Or build it with a ./gradlew shadowJar, the jar will be located here build/libs/akhq-*.jar

Development Server

A docker-compose is provided to start a development environment. Just install docker & docker-compose, clone the repository and issue a simple docker-compose -f docker-compose-dev.yml up to start a dev server. Dev server is a java server & webpack-dev-server with live reload.

The configuration for the dev server is in application.dev.yml.

Setup local dev environment on Windows

In case you want to develop for AKHQ on Windows with IntelliJ IDEA without Docker (for any reason) you can follow this brief guide. For the following steps, please, make sure you meet these requirements:

• OS: Windows (10)
• Kafka (2.6.0) is downloaded and extracted, the installation directory is referred to as $KAFKA_HOME in the latter
• Git is installed and configured
• IntelliJ IDEA (Community Edition 2020.2) with the following plugins installed:
  • Gradle (bundled with IDEA)
  • Lombok

First run a Kafka server locally. Therefore, you need to start Zookeeper first by opening a CMD and doing:

$KAFKA_HOME\bin\windows\zookeeper-server-start.bat config\zookeper.properties
$KAFKA_HOME\bin\windows\kafka-server-start.bat config\server.properties

A zero-config Kafka server should be up and running locally on your machine now. For further details or troubleshooting see Kafka Getting started guide. In the next step we're going to checkout AKHQ from GitHub:

git clone https://github.com/tchiotludo/akhq.git

Open the checked out directory in IntelliJ IDEA. The current version (0.16.0) of AKHQ is built with Java 11. If you don't have OpenJDK 11 installed already, do the following in IntelliJ IDEA: File > Project Structure... > Platform Settings > SDKs > + > Download JDK... > select a vendor of your choice (but make sure it's version 11), download + install. Make sure that JDK 11 is set under Project Settings > Project SDK and language level is Java 11. Now tell Gradle to use Java 11 as well: File > Settings > Plugins > Build, Execution, Deployment > Build Tools > Gradle > Gradle JVM: any JDK 11.

To configure AKHQ for using the Kafka server you set up before, edit application.yml by adding the following under akhq:

akhq:
  connections:
    kafka:
      properties:
        bootstrap.servers: "localhost:9092"

/!\ Do not commit this part of application.yml. A more secure way to configure your local development Kafka server is described in the Micronaut doc, chapter "Application Configuration".

Now you should be able to build the project with Gradle. Therefore, go to the Gradle view in IDEA, select Tasks > build > build. If an error occurs saying that any filename is too long: move your project directory to a root directory in your filesystem or as a fix (only for testing purposes) set the argument -x test to skip tests temporarily.

To debug a running AKHQ instance, go to the Gradle tab in IntelliJ IDEA, Tasks > application > right click run and click "Debug(...)". AKHQ should start up and hit the breakpoints you set in your IDE. Happy developing/debugging!

Schema references

Since Confluent 5.5.0, Avro schemas can now be reused by others schemas through schema references. This feature allows to define a schema once and use it as a record type inside one or more schemas.

When registering new Avro schemas with AKHQ UI, it is now possible to pass a slightly more complex object with a schema and a references field.

To register a new schema without references, no need to change anything:

{
    "name": "Schema1",
    "namespace": "org.akhq",
    "type": "record",
    "fields": [
        {
            "name": "description",
            "type": "string"
        }
    ]
}

To register a new schema with a reference to an already registered schema:

{
    "schema": {
        "name": "Schema2",
        "namespace": "org.akhq",
        "type": "record",
        "fields": [
            {
                "name": "name",
                "type": "string"
            },
            {
                "name": "schema1",
                "type": "Schema1"
            }
        ]
    },
    "references": [
        {
            "name": "Schema1",
            "subject": "SCHEMA_1",
            "version": 1
        }
    ]
}

Documentation on Confluent 5.5 and schema references can be found here.

Who's using AKHQ

• Adeo
• Auchan Retail
• Bell
• BMW Group
• Boulanger
• GetYourGuide
• Klarna
• La Redoute
• Leroy Merlin
• NEXT Technologies
• Nuxeo
• Pipedrive
• BARMER
• TVG
• Depop
• BPCE-IT

Credits

Many thanks to:

• JetBrains for their free OpenSource license.
• Apache, Apache Kafka, Kafka, and associated open source project names are trademarks of the Apache Software Foundation. AKHQ is not affiliated with, endorsed by, or otherwise associated with the Apache Software.

License

Apache 2.0 © tchiotludo