ruby

Overview

Produce messages to and consume messages from Confluent Cloud using the ZenDesk Ruby Client for Apache Kafka.

Prerequisites

• Bundler installed on your machine. Install via gem install bundler
• Access to a Confluent Cloud cluster
• Local file with configuration parameters to connect to your Confluent Cloud instance (how do I find those?). Format the file as follows:

  $ cat ~/.ccloud/example.config
  bootstrap.servers=<broker-1,broker-2,broker-3>
  sasl.username=<api-key-id>
  sasl.password=<secret-access-key>

• Install gems

  $ cd clients/ruby
  $ bundle install

Example 1: Hello World!

In this example, the producer writes Kafka data to a topic in Confluent Cloud. Each record has a key representing a username (e.g. alice) and a value of a count, formatted as json (e.g. {"count": 0}). The consumer reads the same topic from Confluent Cloud and keeps a rolling sum of the counts as it processes each record.

1. Run the producer, passing in arguments for (a) the local file with configuration parameters to connect to your Confluent Cloud instance and (b) the topic name:

   $ ruby producer.rb -f ~/.ccloud/example.config --topic test1
   Created topic test1
   Producing record: alice	{"count":0}
   Producing record: alice	{"count":1}
   Producing record: alice	{"count":2}
   Producing record: alice	{"count":3}
   Producing record: alice	{"count":4}
   Producing record: alice	{"count":5}
   Producing record: alice	{"count":6}
   Producing record: alice	{"count":7}
   Producing record: alice	{"count":8}
   Producing record: alice	{"count":9}
   10 messages were successfully produced to topic test1!

2. Run the consumer, passing in arguments for (a) the local file with configuration parameters to connect to your Confluent Cloud instance and (b) the same topic name as used above. Verify that the consumer received all the messages:

   $ ruby consumer.rb -f ~/.ccloud/example.config --topic test1
   Consuming messages from test1
   Consumed record with key alice and value {"count":0}, and updated total count 0
   Consumed record with key alice and value {"count":1}, and updated total count 1
   Consumed record with key alice and value {"count":2}, and updated total count 3
   Consumed record with key alice and value {"count":3}, and updated total count 6
   Consumed record with key alice and value {"count":4}, and updated total count 10
   Consumed record with key alice and value {"count":5}, and updated total count 15
   Consumed record with key alice and value {"count":6}, and updated total count 21
   Consumed record with key alice and value {"count":7}, and updated total count 28
   Consumed record with key alice and value {"count":8}, and updated total count 36
   Consumed record with key alice and value {"count":9}, and updated total count 45
   ...