Bitnami Docker Image for Kafka

What is Kafka?

Apache Kafka is a distributed streaming platform used for building real-time data pipelines and streaming apps. It is horizontally scalable, fault-tolerant, wicked fast, and runs in production in thousands of companies. Kafka requires a connection to a Zookeeper service.

https://kafka.apache.org/

TL;DR

Run the application using Docker Compose

The main folder of this repository contains a functional docker-compose.yml file. Run the application using it as shown below:

$ curl -sSL https://raw.githubusercontent.com/bitnami/bitnami-docker-kafka/master/docker-compose.yml > docker-compose.yml
$ docker-compose up -d

Why use Bitnami Images?

• Bitnami closely tracks upstream source changes and promptly publishes new versions of this image using our automated systems.
• With Bitnami images the latest bug fixes and features are available as soon as possible.
• Bitnami containers, virtual machines and cloud images use the same components and configuration approach - making it easy to switch between formats based on your project needs.
• All our images are based on minideb a minimalist Debian based container image which gives you a small base container image and the familiarity of a leading Linux distribution.
• All Bitnami images available in Docker Hub are signed with Docker Content Trust (DCT). You can use DOCKER_CONTENT_TRUST=1 to verify the integrity of the images.
• Bitnami container images are released daily with the latest distribution packages available.

This CVE scan report contains a security report with all open CVEs. To get the list of actionable security issues, find the "latest" tag, click the vulnerability report link under the corresponding "Security scan" field and then select the "Only show fixable" filter on the next page.

How to deploy Apache Kafka in Kubernetes?

Deploying Bitnami applications as Helm Charts is the easiest way to get started with our applications on Kubernetes. Read more about the installation in the Bitnami Apache Kafka Chart GitHub repository.

Bitnami containers can be used with Kubeapps for deployment and management of Helm Charts in clusters.

Why use a non-root container?

Non-root container images add an extra layer of security and are generally recommended for production environments. However, because they run as a non-root user, privileged tasks are typically off-limits. Learn more about non-root containers in our docs.

Supported tags and respective Dockerfile links

Learn more about the Bitnami tagging policy and the difference between rolling tags and immutable tags in our documentation page.

• 2, 2-debian-10, 2.7.0, 2.7.0-debian-10-r88, latest (2/debian-10/Dockerfile)

Subscribe to project updates by watching the bitnami/kafka GitHub repo.

Get this image

The recommended way to get the Bitnami Kafka Docker Image is to pull the prebuilt image from the Docker Hub Registry.

$ docker pull bitnami/kafka:latest

To use a specific version, you can pull a versioned tag. You can view the list of available versions in the Docker Hub Registry.

$ docker pull bitnami/kafka:[TAG]

If you wish, you can also build the image yourself.

docker build -t bitnami/kafka:latest 'https://github.com/bitnami/bitnami-docker-kafka.git#master:2/debian-10'

Persisting your data

If you remove the container all your data and configurations will be lost, and the next time you run the image the database will be reinitialized. To avoid this loss of data, you should mount a volume that will persist even after the container is removed.

Note: If you have already started using your database, follow the steps on backing up and restoring to pull the data from your running container down to your host.

The image exposes a volume at /bitnami/kafka for the Kafka data. For persistence you can mount a directory at this location from your host. If the mounted directory is empty, it will be initialized on the first run.

Using Docker Compose:

This requires a minor change to the docker-compose.yml file present in this repository:

kafka:
  ...
  volumes:
    - /path/to/kafka-persistence:/bitnami/kafka
  ...

NOTE: As this is a non-root container, the mounted files and directories must have the proper permissions for the UID 1001.

Connecting to other containers

Using Docker container networking, a Kafka server running inside a container can easily be accessed by your application containers.

Containers attached to the same network can communicate with each other using the container name as the hostname.

Using the Command Line

In this example, we will create a Kafka client instance that will connect to the server instance that is running on the same docker network as the client.

Step 1: Create a network

$ docker network create app-tier --driver bridge

Step 2: Launch the Zookeeper server instance

Use the --network app-tier argument to the docker run command to attach the Zookeeper container to the app-tier network.

$ docker run -d --name zookeeper-server \
    --network app-tier \
    -e ALLOW_ANONYMOUS_LOGIN=yes \
    bitnami/zookeeper:latest

Step 2: Launch the Kafka server instance

Use the --network app-tier argument to the docker run command to attach the Kafka container to the app-tier network.

$ docker run -d --name kafka-server \
    --network app-tier \
    -e ALLOW_PLAINTEXT_LISTENER=yes \
    -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper-server:2181 \
    bitnami/kafka:latest

Step 3: Launch your Kafka client instance

Finally we create a new container instance to launch the Kafka client and connect to the server created in the previous step:

$ docker run -it --rm \
    --network app-tier \
    -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper-server:2181 \
    bitnami/kafka:latest kafka-topics.sh --list  --zookeeper zookeeper-server:2181

Using Docker Compose

When not specified, Docker Compose automatically sets up a new network and attaches all deployed services to that network. However, we will explicitly define a new bridge network named app-tier. In this example we assume that you want to connect to the Kafka server from your own custom application image which is identified in the following snippet by the service name myapp.

version: '2'

networks:
  app-tier:
    driver: bridge

services:
  zookeeper:
    image: 'bitnami/zookeeper:latest'
    networks:
      - app-tier
  kafka:
    image: 'bitnami/kafka:latest'
    networks:
      - app-tier
  myapp:
    image: 'YOUR_APPLICATION_IMAGE'
    networks:
      - app-tier

IMPORTANT:

1. Please update the YOUR_APPLICATION_IMAGE placeholder in the above snippet with your application image
2. Configure Kafka and ZooKeeper persistence, and configure them either via environment variables or by mounting configuration files.
3. In your application container, use the hostname kafka to connect to the Kafka server

Launch the containers using:

$ docker-compose up -d

Configuration

The configuration can easily be setup with the Bitnami Kafka Docker image using the following environment variables:

• ALLOW_PLAINTEXT_LISTENER: Allow to use the PLAINTEXT listener. Default: no.
• KAFKA_INTER_BROKER_USER: Kafka inter broker communication user. Default: admin. Default: user.
• KAFKA_INTER_BROKER_PASSWORD: Kafka inter broker communication password. Default: bitnami.
• KAFKA_CLIENT_USER: Kafka client user. Deprecated in favor of KAFKA_CLIENT_USERS.
• KAFKA_CLIENT_PASSWORD: Kafka client user password. Deprecated in favor of KAFKA_CLIENT_PASSWORDS.
• KAFKA_CERTIFICATE_PASSWORD: Password for certificates. No defaults.
• KAFKA_HEAP_OPTS: Kafka's Java Heap size. Default: -Xmx1024m -Xms1024m.
• KAFKA_ZOOKEEPER_PROTOCOL: Authentication protocol for Zookeeper connections. Allowed protocols: PLAINTEXT, SASL, SSL, and SASL_SSL. Defaults: PLAINTEXT.
• KAFKA_ZOOKEEPER_USER: Kafka Zookeeper user for SASL authentication. No defaults.
• KAFKA_ZOOKEEPER_PASSWORD: Kafka Zookeeper user password for SASL authentication. No defaults.
• KAFKA_ZOOKEEPER_TLS_KEYSTORE_PASSWORD: Kafka Zookeeper keystore file password and key password. No defaults.
• KAFKA_ZOOKEEPER_TLS_TRUSTSTORE_PASSWORD: Kafka Zookeeper truststore file password. No defaults.
• KAFKA_ZOOKEEPER_TLS_VERIFY_HOSTNAME: Verify Zookeeper hostname on TLS certificates. Defaults: true.
• KAFKA_ZOOKEEPER_TLS_TYPE: Choose the TLS certificate format to use. Allowed values: JKS, PEM. Defaults: JKS.
• KAFKA_CFG_SASL_ENABLED_MECHANISMS: Allowed mechanism when using SASL either for clients, inter broker, or zookeeper comunications. Allowed values: PLAIN, SCRAM-SHA-256, SCRAM-SHA-512 or a comma separated combination of those values. Default: PLAIN,SCRAM-SHA-256,SCRAM-SHA-512
• KAFKA_CFG_SASL_MECHANISM_INTER_BROKER_PROTOCOL: SASL mechanism to use for inter broker communications. No defaults.
• KAFKA_CFG_TLS_CLIENT_AUTH: Configures kafka brokers to request client authentication. Allowed values: required, requested, none. Defaults: required.
• KAFKA_CFG_TLS_TYPE: Choose the TLS certificate format to use. Allowed values: JKS, PEM. Defaults: JKS.
• KAFKA_CLIENT_USERS: Additional users to KAFKA_CLIENT_USER that will be created into Zookeeper when using SASL_SCRAM for client communications. Separated by commas. Default: user
• KAFKA_CLIENT_PASSWORDS: Passwords for the users specified atKAFKA_CLIENT_USERS. Separated by commas. Default: bitnami

Additionally, any environment variable beginning with KAFKA_CFG_ will be mapped to its corresponding Kafka key. For example, use KAFKA_CFG_BACKGROUND_THREADS in order to set background.threads or KAFKA_CFG_AUTO_CREATE_TOPICS_ENABLE in order to configure auto.create.topics.enable.

$ docker run --name kafka -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181 -e ALLOW_PLAINTEXT_LISTENER=yes -e KAFKA_CFG_AUTO_CREATE_TOPICS_ENABLE=true bitnami/kafka:latest

or by modifying the docker-compose.yml file present in this repository:

kafka:
  ...
  environment:
    - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
  ...

Kafka development setup example

To use Kafka in a development setup, create the following docker-compose.yml file:

version: "3"
services:
  zookeeper:
    image: 'bitnami/zookeeper:latest'
    ports:
      - '2181:2181'
    environment:
      - ALLOW_ANONYMOUS_LOGIN=yes
  kafka:
    image: 'bitnami/kafka:latest'
    ports:
      - '9092:9092'
    environment:
      - KAFKA_BROKER_ID=1
      - KAFKA_LISTENERS=PLAINTEXT://:9092
      - KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://127.0.0.1:9092
      - KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes
    depends_on:
      - zookeeper

To deploy it, run the following command in the directory where the docker-compose.yml file is located:

docker-compose up -d

Accessing Kafka with internal and external clients

In order to use internal and external clients to access Kafka brokers you need to configure one listener for each kind of clients.

To do so, add the following environment variables to your docker-compose:

    environment:
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes
+     - KAFKA_CFG_LISTENER_SECURITY_PROTOCOL_MAP=CLIENT:PLAINTEXT,EXTERNAL:PLAINTEXT
+     - KAFKA_CFG_LISTENERS=CLIENT://:9092,EXTERNAL://:9093
+     - KAFKA_CFG_ADVERTISED_LISTENERS=CLIENT://kafka:9092,EXTERNAL://localhost:9093
+     - KAFKA_INTER_BROKER_LISTENER_NAME=CLIENT

And expose the external port:

(the internal, client one can still be used within the docker network)

    ports:
-     - '9092:9092'
+     - '9093:9093'

Producer and consumer using external client

These clients, from the host, will use localhost to connect to Kafka.

kafka-console-producer.sh --broker-list 127.0.0.1:9093 --topic test
kafka-console-consumer.sh --bootstrap-server 127.0.0.1:9093 --topic test --from-beginning

Producer and consumer using internal client

These clients, from other containers on the same Docker network, will use the kafka container service hostname to connect to Kafka.

kafka-console-producer.sh --broker-list kafka:9092 --topic test
kafka-console-consumer.sh --bootstrap-server kafka:9092 --topic test --from-beginning

Similarly, application code will need to use bootstrap.servers=kafka:9092

More info about Kafka listeners can be found in this great article

Security

The Bitnami Kafka docker image disables the PLAINTEXT listener for security reasons. You can enable the PLAINTEXT listener by adding the next environment variable, but remember that this configuration is not recommended for production.

ALLOW_PLAINTEXT_LISTENER=yes

In order to configure authentication, you must configure the Kafka listeners properly. This container assumes the names below will be used for the listeners:

• INTERNAL: used for inter-broker communications.
• CLIENT: used for coummunications with clients that are within the same network as Kafka brokers.

Let's see an example to configure Kafka with SASL_SSL authentication for communications with clients, and SSL authentication for inter-broker communication.

The environment variables below should be define to configure the listeners, and the SASL credentials for client communications:

KAFKA_CFG_LISTENER_SECURITY_PROTOCOL_MAP=INTERNAL:SSL,CLIENT:SASL_SSL
KAFKA_CFG_LISTENERS=INTERNAL://:9093,CLIENT://:9092
KAFKA_CFG_ADVERTISED_LISTENERS=INTERNAL://kafka:9093,CLIENT://kafka:9092
KAFKA_CLIENT_USER=user
KAFKA_CLIENT_PASSWORD=password

You must also use your own certificates for SSL. You can drop your Java Key Stores or PEM files into /opt/bitnami/kafka/config/certs. If the JKS or PEM is password protected (recommended), you will need to provide it to get access to the keystores:

KAFKA_CERTIFICATE_PASSWORD=myCertificatePassword

The following script can help you with the creation of the JKS and certificates:

• kafka-generate-ssl.sh

Keep in mind the following notes:

• When prompted to enter a password, use the same one for all.
• Set the Common Name or FQDN values to your Kafka container hostname, e.g. kafka.example.com. After entering this value, when prompted "What is your first and last name?", enter this value as well.
  • As an alternative, you can disable host name verification setting the environment variable KAFKA_CFG_SSL_ENDPOINT_IDENTIFICATION_ALGORITHM to an empty string.
• When setting up a Kafka Cluster (check this section for more information), each Kafka broker and logical client needs its own keystore. You will have to repeat the process for each of the brokers in the cluster.

The following docker-compose file is an example showing how to mount your JKS certificates protected by the password certificatePassword123. Additionally it is specifying the Kafka container hostname and the credentials for the client and zookeeper users.

version: '2'

services:
  zookeeper:
    image: 'bitnami/zookeeper:latest'
    ports:
     - '2181:2181'
    environment:
      - ZOO_ENABLE_AUTH=yes
      - ZOO_SERVER_USERS=kafka
      - ZOO_SERVER_PASSWORDS=kafka_password
  kafka:
    image: 'bitnami/kafka:latest'
    hostname: kafka.example.com
    ports:
      - '9092'
    environment:
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - KAFKA_CFG_LISTENERS=SASL_SSL://:9092
      - KAFKA_CFG_ADVERTISED_LISTENERS=SASL_SSL://:9092
      - KAFKA_ZOOKEEPER_USER=kafka
      - KAFKA_ZOOKEEPER_PASSWORD=kafka_password
      - KAFKA_CLIENT_USER=user
      - KAFKA_CLIENT_PASSWORD=password
      - KAFKA_CERTIFICATE_PASSWORD=certificatePassword123
      - KAFKA_CFG_TLS_TYPE=JKS # or PEM
    volumes:
      # Both .jks and .pem files are supported
      - './kafka.keystore.jks:/opt/bitnami/kafka/config/certs/kafka.keystore.jks:ro'
      - './kafka.truststore.jks:/opt/bitnami/kafka/config/certs/kafka.truststore.jks:ro'

In order to get the required credentials to consume and produce messages you need to provide the credentials in the client. If your Kafka client allows it, use the credentials you've provided.

While producing and consuming messages using the bitnami/kafka image, you'll need to point to the consumer.properties and/or producer.properties file, which contains the needed configuration to work. You can find this files in the /opt/bitnami/kafka/conf directory.

Use this to generate messages using a secure setup:

export KAFKA_OPTS="-Djava.security.auth.login.config=/opt/bitnami/kafka/conf/kafka_jaas.conf"
kafka-console-producer.sh --broker-list 127.0.0.1:9092 --topic test --producer.config /opt/bitnami/kafka/conf/producer.properties

Use this to consume messages using a secure setup

export KAFKA_OPTS="-Djava.security.auth.login.config=/opt/bitnami/kafka/conf/kafka_jaas.conf"
kafka-console-consumer.sh --bootstrap-server 127.0.0.1:9092 --topic test --consumer.config /opt/bitnami/kafka/conf/consumer.properties

If you use other tools to use your Kafka cluster, you'll need to provide the required information. You can find the required information in the files located at /opt/bitnami/kafka/conf directory.

InterBroker communications

When configuring your broker to use SASL or SASL_SSL for inter-broker communications, you can provide the SASL credentials using these environment variables:

• KAFKA_INTER_BROKER_USER: Kafka inter broker communication user. Deprecated in favor of KAFKA_CLIENT_USERS.
• KAFKA_INTER_BROKER_PASSWORD: Kafka inter broker communication password. Deprecated in favor of KAFKA_CLIENT_PASSWORDS.

Kafka client configuration

When configuring Kafka with SASL or SASL_SSL for communications with clients, you can provide your the SASL credentials using this environment variables:

• KAFKA_CLIENT_USER: Kafka client user. Default: user
• KAFKA_CLIENT_PASSWORD: Kafka client user password. Default: bitnami

Kafka ZooKeeper client configuration

There are different options of configuration to connect a Zookeeper server.

In order to connect a Zookeeper server without authentication, you should provide the environment variables below:

• KAFKA_ZOOKEEPER_PROTOCOL: PLAINTEXT.

In order to authenticate Kafka against a Zookeeper server with SASL, you should provide the environment variables below:

• KAFKA_ZOOKEEPER_PROTOCOL: SASL.
• KAFKA_ZOOKEEPER_USER: Kafka Zookeeper user for SASL authentication. No defaults.
• KAFKA_ZOOKEEPER_PASSWORD: Kafka Zookeeper user password for SASL authentication. No defaults.

In order to authenticate Kafka against a Zookeeper server with SSL, you should provide the environment variables below:

• KAFKA_ZOOKEEPER_PROTOCOL: SSL.
• KAFKA_ZOOKEEPER_TLS_KEYSTORE_PASSWORD: Kafka Zookeeper keystore file password and key password. No defaults.
• KAFKA_ZOOKEEPER_TLS_TRUSTSTORE_PASSWORD: Kafka Zookeeper truststore file password. No defaults.
• KAFKA_ZOOKEEPER_TLS_VERIFY_HOSTNAME: Verify Zookeeper hostname on TLS certificates. Defaults: true.
• KAFKA_ZOOKEEPER_TLS_TYPE: Choose the TLS certificate format to use. Allowed values: JKS, PEM. Defaults: JKS.

In order to authenticate Kafka against a Zookeeper server with SASL_SSL, you should provide the environment variables below:

• KAFKA_ZOOKEEPER_PROTOCOL: SASL_SSL.
• KAFKA_ZOOKEEPER_USER: Kafka Zookeeper user for SASL authentication. No defaults.
• KAFKA_ZOOKEEPER_PASSWORD: Kafka Zookeeper user password for SASL authentication. No defaults.
• KAFKA_ZOOKEEPER_TLS_KEYSTORE_PASSWORD: Kafka Zookeeper keystore file password and key password. No defaults.
• KAFKA_ZOOKEEPER_TLS_TRUSTSTORE_PASSWORD: Kafka Zookeeper truststore file password. No defaults.
• KAFKA_ZOOKEEPER_TLS_VERIFY_HOSTNAME: Verify Zookeeper hostname on TLS certificates. Defaults: true.
• KAFKA_ZOOKEEPER_TLS_TYPE: Choose the TLS certificate format to use. Allowed values: JKS, PEM. Defaults: JKS.

Note: You must also use your own certificates for SSL. You can mount your Java Key Stores or PEM files (zookeeper.keystore.jks|.pem and zookeeper.truststore.jks|.pem) into /opt/bitnami/kafka/conf/certs. If client authentication is none or want in Zookeeper, the keystore file is optional.

Setting up a Kafka Cluster

A Kafka cluster can easily be setup with the Bitnami Kafka Docker image using the following environment variables:

• KAFKA_CFG_ZOOKEEPER_CONNECT: Comma separated host:port pairs, each corresponding to a Zookeeper Server.

Create a Docker network to enable visibility to each other via the docker container name

$ docker network create app-tier --driver bridge

Step 1: Create the first node for Zookeeper

The first step is to create one Zookeeper instance.

$ docker run --name zookeeper \
  --network app-tier \
  -e ALLOW_ANONYMOUS_LOGIN=yes \
  -p 2181:2181 \
  bitnami/zookeeper:latest

Step 2: Create the first node for Kafka

The first step is to create one Kafka instance.

$ docker run --name kafka1 \
  --network app-tier \
  -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181 \
  -e ALLOW_PLAINTEXT_LISTENER=yes \
  -p 9092:9092 \
  bitnami/kafka:latest

Step 2: Create the second node

Next we start a new Kafka container.

$ docker run --name kafka2 \
  --network app-tier \
  -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181 \
  -e ALLOW_PLAINTEXT_LISTENER=yes \
  -p 9092:9092 \
  bitnami/kafka:latest

Step 3: Create the third node

Next we start another new Kafka container.

$ docker run --name kafka3 \
  --network app-tier \
  -e KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181 \
  -e ALLOW_PLAINTEXT_LISTENER=yes \
  -p 9092:9092 \
  bitnami/kafka:latest

You now have a Kafka cluster up and running. You can scale the cluster by adding/removing slaves without incurring any downtime.

With Docker Compose, topic replication can be setup using:

version: '2'

services:
  zookeeper:
    image: 'bitnami/zookeeper:latest'
    ports:
     - '2181:2181'
    environment:
     - ALLOW_ANONYMOUS_LOGIN=yes
  kafka1:
    image: 'bitnami/kafka:latest'
    ports:
      - '9092'
    environment:
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes
  kafka2:
    image: 'bitnami/kafka:latest'
    ports:
      - '9092'
    environment:
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes
  kafka3:
    image: 'bitnami/kafka:latest'
    ports:
      - '9092'
    environment:
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes

Then, you can create a replicated topic with:

--create --zookeeper zookeeper:2181 --topic mytopic --partitions 3 --replication-factor 3
Created topic "mytopic".

--describe --zookeeper zookeeper:2181 --topic mytopic
Topic:mytopic   PartitionCount:3        ReplicationFactor:3     Configs:
        Topic: mytopic  Partition: 0    Leader: 2       Replicas: 2,3,1 Isr: 2,3,1
        Topic: mytopic  Partition: 1    Leader: 3       Replicas: 3,1,2 Isr: 3,1,2
        Topic: mytopic  Partition: 2    Leader: 1       Replicas: 1,2,3 Isr: 1,2,3

Full configuration

The image looks for configuration files (server.properties, log4j.properties, etc.) in the /bitnami/kafka/config/ directory, this directory can be changed by setting the KAFKA_MOUNTED_CONF_DIR environment variable.

$ docker run --name kafka -v /path/to/server.properties:/bitnami/kafka/config/server.properties bitnami/kafka:latest

After that, your changes will be taken into account in the server's behaviour.

Step 1: Run the Kafka image

Run the Kafka image, mounting a directory from your host.

Modify the docker-compose.yml file present in this repository:

...
services:
  kafka:
    ...
    volumes:
      - 'kafka_data:/bitnami'
+     - /path/to/server.properties:/bitnami/kafka/config/server.properties

Step 2: Edit the configuration

Edit the configuration on your host using your favorite editor.

vi /path/to/server.properties

Step 3: Restart Kafka

After changing the configuration, restart your Kafka container for changes to take effect.

$ docker restart kafka

Or using Docker Compose:

$ docker-compose restart kafka

Logging

The Bitnami Kafka Docker image sends the container logs to the stdout. To view the logs:

$ docker logs kafka

Or using Docker Compose:

$ docker-compose logs kafka

You can configure the containers logging driver using the --log-driver option if you wish to consume the container logs differently. In the default configuration docker uses the json-file driver.

Maintenance

Backing up your container

To backup your data, configuration and logs, follow these simple steps:

Step 1: Stop the currently running container

$ docker stop kafka

Or using Docker Compose:

$ docker-compose stop kafka

Step 2: Run the backup command

We need to mount two volumes in a container we will use to create the backup: a directory on your host to store the backup in, and the volumes from the container we just stopped so we can access the data.

$ docker run --rm -v /path/to/kafka-backups:/backups --volumes-from kafka busybox \
  cp -a /bitnami/kafka:latest /backups/latest

Or using Docker Compose:

$ docker run --rm -v /path/to/kafka-backups:/backups --volumes-from `docker-compose ps -q kafka` busybox \
  cp -a /bitnami/kafka:latest /backups/latest

Restoring a backup

Restoring a backup is as simple as mounting the backup as volumes in the container.

$ docker run -v /path/to/kafka-backups/latest:/bitnami/kafka bitnami/kafka:latest

You can also modify the docker-compose.yml file present in this repository:

kafka:
  volumes:
    - /path/to/kafka-backups/latest:/bitnami/kafka

Upgrade this image

Bitnami provides up-to-date versions of Kafka, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

Step 1: Get the updated image

$ docker pull bitnami/kafka:latest

or if you're using Docker Compose, update the value of the image property to bitnami/kafka:latest.

Step 2: Stop and backup the currently running container

Before continuing, you should backup your container's data, configuration and logs.

Follow the steps on creating a backup.

Step 3: Remove the currently running container

$ docker rm -v kafka

Or using Docker Compose:

$ docker-compose rm -v kafka

Step 4: Run the new image

Re-create your container from the new image, restoring your backup if necessary.

$ docker run --name kafka bitnami/kafka:latest

Or using Docker Compose:

$ docker-compose up kafka

Notable Changes

2.5.0-debian-10-r111

• The KAFKA_CLIENT_USER AND KAFKA-CLIENT-PASSWORD have been deprecated in favor of KAFKA_CLIENT_USERS and KAFKA_CLIENT_PASSWORDS.

2.5.0-debian-10-r51

• The environment variables KAFKA_PORT_NUMBER and KAFKA_CFG_PORT was deprecated, you can specify the port number in KAFKA_CFG_LISTENERS instead.

• The following environment variables were renamed:

  • KAFKA_BROKER_USER -> KAFKA_CLIENT_USER
  • KAFKA_BROKER_PASSWORD -> KAFKA_CLIENT_PASSWORD

• Listeners & advertised listeners must be configured to enable authentication. Check Security section for more information.

2.4.1-r38-debian-10

The configuration directory was changed to /opt/bitnami/kafka/config. Configuration files should be mounted to /bitnami/kafka/config.

1.1.1-debian-9-r224, 2.2.1-debian-9-r16, 1.1.1-ol-7-r306 and 2.2.1-ol-7-r14

• The following environment variables were beingly wrongly translated into KAFKA_CFG_ environment variables, and therefore they were being wrongly mapped into Kafka keys:

  • KAFKA_LOGS_DIRS -> KAFKA_CFG_LOG_DIRS
  • KAFKA_PORT_NUMBER -> KAFKA_CFG_PORT
  • KAFKA_ZOOKEEPER_CONNECT_TIMEOUT_MS -> KAFKA_CFG_ZOOKEEPER_CONNECTION_TIMEOUT_MS

• For consistency reasons with previous environment variables, the following KAFKA_ to KAFKA_CFG_ environment variable translations are now supported for mapping into Kafka keys:

  • KAFKA_LOG_DIRS -> KAFKA_CFG_LOG_DIRS
  • KAFKA_ZOOKEEPER_CONNECTION_TIMEOUT_MS -> KAFKA_CFG_ZOOKEEPER_CONNECTION_TIMEOUT_MS

1.1.1-debian-9-r205, 2.2.0-debian-9-r40, 1.1.1-ol-7-r286, and 2.2.0-ol-7-r53

Configuration changes. Most environment variables now start with KAFKA_CFG_, as they are now mapped directly to Kafka keys. Variables changed:

• KAFKA_ADVERTISED_LISTENERS -> KAFKA_CFG_ADVERTISED_LISTENERS
• KAFKA_BROKER_ID -> KAFKA_CFG_BROKER_ID
• KAFKA_DEFAULT_REPLICATION_FACTOR -> KAFKA_CFG_DEFAULT_REPLICATION_FACTOR
• KAFKA_DELETE_TOPIC_ENABLE -> KAFKA_CFG_DELETE_TOPIC_ENABLE
• KAFKA_INTER_BROKER_LISTENER_NAME -> KAFKA_CFG_INTER_BROKER_LISTENER_NAME
• KAFKA_LISTENERS -> KAFKA_CFG_LISTENERS
• KAFKA_LISTENER_SECURITY_PROTOCOL_MAP -> KAFKA_CFG_LISTENER_SECURITY_PROTOCOL_MAP
• KAFKA_LOGS_DIRS -> KAFKA_CFG_LOG_DIRS
• KAFKA_LOG_FLUSH_INTERVAL_MESSAGES -> KAFKA_CFG_LOG_FLUSH_INTERVAL_MESSAGES
• KAFKA_LOG_FLUSH_INTERVAL_MS -> KAFKA_CFG_LOG_FLUSH_INTERVAL_MS
• KAFKA_LOG_MESSAGE_FORMAT_VERSION -> KAFKA_CFG_LOG_MESSAGE_FORMAT_VERSION
• KAFKA_LOG_RETENTION_BYTES -> KAFKA_CFG_LOG_RETENTION_BYTES
• KAFKA_LOG_RETENTION_CHECK_INTERVALS_MS -> KAFKA_CFG_LOG_RETENTION_CHECK_INTERVAL_MS
• KAFKA_LOG_RETENTION_HOURS -> KAFKA_CFG_LOG_RETENTION_HOURS
• KAFKA_MAX_MESSAGE_BYTES -> KAFKA_CFG_MESSAGE_MAX_BYTES
• KAFKA_NUM_IO_THREADS -> KAFKA_CFG_NUM_IO_THREADS
• KAFKA_NUM_NETWORK_THREADS -> KAFKA_CFG_NUM_NETWORK_THREADS
• KAFKA_NUM_PARTITIONS -> KAFKA_CFG_NUM_PARTITIONS
• KAFKA_NUM_RECOVERY_THREADS_PER_DATA_DIR -> KAFKA_CFG_NUM_RECOVERY_THREADS_PER_DATA_DIR
• KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR -> KAFKA_CFG_OFFSETS_TOPIC_REPLICATION_FACTOR
• KAFKA_PORT -> KAFKA_CFG_PORT
• KAFKA_SEGMENT_BYTES -> KAFKA_CFG_SEGMENT_BYTES
• KAFKA_SOCKET_RECEIVE_BUFFER_BYTES -> KAFKA_CFG_SOCKET_RECEIVE_BUFFER_BYTES
• KAFKA_SOCKET_REQUEST_MAX_BYTES -> KAFKA_CFG_SOCKET_REQUEST_MAX_BYTES
• KAFKA_SOCKET_SEND_BUFFER_BYTES -> KAFKA_CFG_SOCKET_SEND_BUFFER_BYTES
• KAFKA_SSL_ENDPOINT_IDENTIFICATION_ALGORITHM -> KAFKA_CFG_SSL_ENDPOINT_IDENTIFICATION_ALGORITHM
• KAFKA_TRANSACTION_STATE_LOG_MIN_ISR -> KAFKA_CFG_TRANSACTION_STATE_LOG_MIN_ISR
• KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR -> KAFKA_CFG_TRANSACTION_STATE_LOG_REPLICATION_FACTOR
• KAFKA_ZOOKEEPER_CONNECT_TIMEOUT_MS -> KAFKA_CFG_ZOOKEEPER_CONNECT_TIMEOUT_MS
• KAFKA_ZOOKEEPER_CONNECT -> KAFKA_CFG_ZOOKEEPER_CONNECT

1.1.0-r41

• Configuration is not persisted anymore. It should be mounted as a volume or it will be regenerated each time the container is created.
• Dummy certificates are not used anymore when the SASL_SSL listener is configured. These certificates must be mounted as volumes.

0.10.2.1-r3

• The kafka container has been migrated to a non-root container approach. Previously the container run as root user and the kafka daemon was started as kafka user. From now own, both the container and the kafka daemon run as user 1001. As a consequence, the configuration files are writable by the user running the kafka process.

0.10.2.1-r0

• New Bitnami release

Contributing

We'd love for you to contribute to this container. You can request new features by creating an issue, or submit a pull request with your contribution.

Issues

If you encountered a problem running this container, you can file an issue. For us to provide better support, be sure to include the following information in your issue:

• Host OS and version
• Docker version (docker version)
• Output of docker info
• Version of this container (echo $BITNAMI_IMAGE_VERSION inside the container)
• The command you used to run the container, and any relevant output you saw (masking any sensitive information)

License

Copyright (c) 2015-2021 Bitnami

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.