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Make sure Apache Kafka is running. You can start it by following instructions from here.
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Add Karafka to your Gemfile:
# Make sure to install Karafka 2.4 as Karafka 1.4 is no longer maintained
bundle add karafka --version ">= 2.4.0"
- Install Karafka (works for both Rails and standalone applications) by running:
bundle exec karafka install
the above command will create all the necessary files and directories to get you started:
karafka.rb
- main file where you configure Karafka and where you define which consumers should consume what topics.app/consumers/example_consumer.rb
- example consumer.app/consumers/application_consumer.rb
- base consumer from which all consumers should inherit.
- After that, you can run a development console to produce messages to this example topic:
# Works from any place in your code and is thread-safe
# You usually want to produce async but here it may raise exception if Kafka is not available, etc
Karafka.producer.produce_sync(topic: 'example', payload: { 'ping' => 'pong' }.to_json)
- Run the karafka server to start consuming messages:
bundle exec karafka server
# example outcome
[7616dc24-505a-417f-b87b-6bf8fc2d98c5] Polled 2 messages in 1000ms
[dcf3a8d8-0bd9-433a-8f63-b70a0cdb0732] Consume job for ExampleConsumer on example started
{"ping"=>"pong"}
{"ping"=>"pong"}
[dcf3a8d8-0bd9-433a-8f63-b70a0cdb0732] Consume job for ExampleConsumer on example finished in 0ms
Here's the demo of the installation process:
Note: Asciinema videos are not visible when viewing this wiki on GitHub. Please use our
online
documentation instead.
- (Optionally) Install and configure the Web UI by following this documentation section.
If you have any problems settings things up or want a ready application to play around with, then the best idea is just to clone our examples repository:
git clone https://github.com/karafka/example-apps ./example_apps
and follow the instructions from the example apps Wiki.
Karafka ships with a full integration test suite that illustrates various use-cases and edge-cases of working with Karafka and Kafka. Please visit this directory of the Karafka repository to see them.