kartikey-star / publisher-subscriber

publisher-subcriber

The following project is an illustration of using publisher subscriber model to create multiple helm releases. The request to install helm charts are sent to a topic helm_installations and request to uninstall helm charts are sent to topic helm_deletions. The consumer subscribes to these topics, and creates and uninstalls helm releases for the message sent to it.

We are going to need a Kafka Cluster for our client application to operate with. We do have a file called as docker-compose.yml[./docker-compose.yml]. This is used to setup kafka cluster locally as a docker deamon.

In order to create the kafka cluster we can do this by using command:

docker compose up -d

Creating a topic

We need to publish the request to install the helm charts. The request consists of chart_url,namespace and values in JSON format.This helm request has to be sent to a topic. In order to create a topic you can make use of following command:

We need to create two topics helm_installations and helm_deletions

docker compose exec broker \
  kafka-topics --create \
    --topic helm_installations \
    --bootstrap-server localhost:9092 \
    --replication-factor 1 \
    --partitions 1

docker compose exec broker \
  kafka-topics --create \
    --topic helm_deletions \
    --bootstrap-server localhost:9092 \
    --replication-factor 1 \
    --partitions 1

You can list the topic too once created using:

docker compose exec broker \
  kafka-topics --list\
    --bootstrap-server localhost:9092

Once the topic get's created please run the code and you can send request to create and delete helm releases on your kubernetes cluster.

There exist's a sample request in the root level which can be used to test the code.

Additional Sources

In order to learn more about kafka you can go through https://developer.confluent.io/get-started/go.