LetItGo

An example app using elsa

Usage

Install dependencies.

mix deps.get

Start Kafka with divo and divo_kafka.

mix docker.start

At this point, you can write messages to the configured Kafka topic (default let-it-go-topic) by any means. LetItGo provides a helper function to make this easy (and demonstrate producer setup).

Drop into an IEx session running LetItGo and use LetItGo.write/1 to produce messages. This function will accept a single string or a list of strings.

iex -S mix

LetItGo.write("this is a message")
LetItGo.write(["foo", "bar", "baz"])

Messages will be read from Kafka and written to disk in .output/messages. New messages overwrite the file, because I'm lazy and it kept the code simpler.

Reading from Kafka

See the LetItGo.Application module documentation for specifics on configuring your application to read from Kafka and handle messages.

Writing to Kafka

See the LetItGo.KafkaWriter module documentation for specifics on configuring your application to write to Kafka.

Managing Kafka topics

See the LetItGo.TopicCreator module documentation for specifics on ensuring a topic exists to read from/write to.

App configuration

By default, LetItGo assumes you're going to spin up a Kafka cluster in Docker with divo and use a topic named let-it-go-topic. But these can be overwritten in application configuration. The :kafka field must be a keyword list with a hostname atom key and an integer port value. The :topic field must be a string.

# config/config.exs
config :let_it_go,
  kafka: [broker_host_name: 9999],
  topic: "custom-topic-name"