Serverless with Knative Eventing and Quarkus

Getting Started

Currently, you may find here some examples of microservices implementation using different projects from Quarkus. All the examples are divided into the branches and described in a separated articles on my blog. Here's a full list of available examples:

1. Using Knative Serving and Eventing components with Quarkus and Kafka to build event-driven microservices architecture in declarative way. The example is available in the branch master. A detailed guide may be found in the following article: Knative Eventing with Kafka and Quarkus
2. Update to the Knative Eventing focusing on KafkaSink, OpenShift and REST client interaction with event-mesh. A detailed guide may be found in the following article: Serverless on OpenShift with Knative, Quarkus and Kafka

Usage

Architecture

Run with Quarkus

1. Login to OpenShift Dashboard and create the demo-eventing project (oc new-project demo-eventing)
2. Create the Knative Broker with the kn broker create default
3. Build the and deploy to OpenShift by activating the already defined openshift Maven profile: mvn clean package -Popenshift

Test on OpenShift

!!! For those who don't want to deploy using Quarkus Kubernetes extension and Maven.

1. Login to OpenShift Dashboard https://console-openshift-console.apps.qyt1tahi.eastus.aroapp.io/
2. Create your project
3. Create Knative Broker

apiVersion: eventing.knative.dev/v1
kind: Broker
metadata:
  annotations:
    eventing.knative.dev/broker.class: MTChannelBasedBroker
  name: default
spec:
  config:
    apiVersion: v1
    kind: ConfigMap
    name: config-br-default-channel
    namespace: knative-eventing

4. Deploy applications

order-service -> quay.io/pminkows/order-service. Set env KAFKA_TOPIC, TICK_TIMEOUT
stock-service -> quay.io/pminkows/stock-service. Set env KAFKA_TOPIC
payment-service -> quay.io/pminkows/payment-service. Set env KAFKA_TOPIC

5. Create KafkaBinding for each application to inject Kafka address (only older versions of Kafka)

For stock-service:

apiVersion: bindings.knative.dev/v1beta1
kind: KafkaBinding
metadata:
  name: kafka-binding-stock
spec:
  subject:
    apiVersion: serving.knative.dev/v1
    kind: Service
    name: stock-service
  bootstrapServers:
    - my-cluster-kafka-bootstrap.kafka:9092

For payment-service:

apiVersion: bindings.knative.dev/v1beta1
kind: KafkaBinding
metadata:
  name: kafka-binding-payment
spec:
  subject:
    apiVersion: serving.knative.dev/v1
    kind: Service
    name: payment-service
  bootstrapServers:
    - my-cluster-kafka-bootstrap.kafka:9092

For order-service:

apiVersion: bindings.knative.dev/v1beta1
kind: KafkaBinding
metadata:
  name: kafka-binding-order
spec:
  subject:
    apiVersion: serving.knative.dev/v1
    kind: Service
    name: order-service
  bootstrapServers:
    - my-cluster-kafka-bootstrap.kafka:9092

6. Create KafkaSource to get messages from Kafka and send them to the Knative Broker

apiVersion: sources.knative.dev/v1beta1
kind: KafkaSource
metadata:
  name: kafka-source-to-broker
spec:
  bootstrapServers:
    - my-cluster-kafka-bootstrap.kafka:9092
  topics:
    - <your-order-events-topic>
    - <your-reserve-events-topic>
  sink:
    ref:
      apiVersion: eventing.knative.dev/v1
      kind: Broker
      name: default

7. Create Knative Trigger for applications

For stock-service:

apiVersion: eventing.knative.dev/v1
kind: Trigger
metadata:
  name: stock-trigger
spec:
  broker: default
  filter:
    attributes:
      source: /apis/v1/namespaces/<your-namespace>/kafkasources/kafka-source-to-broker#<your-topic>
      type: dev.knative.kafka.event
  subscriber:
    ref:
      apiVersion: serving.knative.dev/v1
      kind: Service
      name: stock-service
    uri: /reserve

For payment-service:

apiVersion: eventing.knative.dev/v1
kind: Trigger
metadata:
  name: payment-trigger
spec:
  broker: default
  filter:
    attributes:
      source: /apis/v1/namespaces/<your-namespace>/kafkasources/kafka-source-to-broker#<your-topic>
      type: dev.knative.kafka.event
  subscriber:
    ref:
      apiVersion: serving.knative.dev/v1
      kind: Service
      name: payment-service
    uri: /reserve

For order-service:

apiVersion: eventing.knative.dev/v1
kind: Trigger
metadata:
  name: order-trigger
spec:
  broker: default
  filter:
    attributes:
      source: /apis/v1/namespaces/<your-namespace>/kafkasources/kafka-source-to-broker#<your-topic>
      type: dev.knative.kafka.event
  subscriber:
    ref:
      apiVersion: serving.knative.dev/v1
      kind: Service
      name: order-service
    uri: /confirm

8. Configure autoscaling for payment-service and stock-service

Edit Knative Service YAML and add the following annotations:

      annotations:
        autoscaling.knative.dev/target: "50"
        autoscaling.knative.dev/metric: "rps"

9. Change timeout for order-service

Edit Knative Service YAML and change TICK_TIMEOUT env