Learn KUBELESS with Real Code Examples

# kubeless/demo/python-http.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: hello-python
    namespace: default
spec:
    runtime: python3.8
    handler: handler.main
    source: |
        def main(event, context):
        return "Hello Kubeless!"
    events:
        hello-http:
        type: http
        metadata:
        path: /hello
        method: GET

A simple Kubeless YAML configuration to deploy a Python HTTP function.

# kubeless/demo/node-http.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: hello-node
    namespace: default
spec:
    runtime: nodejs14
    handler: handler.main
    source: |
        module.exports.main = (event, context) => {
        return 'Hello from Node.js!';
        };
    events:
        hello-http:
        type: http
        metadata:
        path: /node
        method: GET

Kubeless function using Node.js runtime to handle HTTP requests.

# kubeless/demo/go-http.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: hello-go
    namespace: default
spec:
    runtime: go1.15
    handler: handler.Hello
    source: |
        package handler
        import (
        "fmt"
        "github.com/kubeless/kubeless/pkg/functions"
        )
        func Hello(event functions.Event, context functions.Context) string {
        return fmt.Sprintf("Hello from Go!")
        }
    events:
        hello-http:
        type: http
        metadata:
        path: /go
        method: GET

Kubeless function using Go runtime to handle HTTP requests.

# kubeless/demo/ruby-http.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: hello-ruby
    namespace: default
spec:
    runtime: ruby2.5
    handler: handler.main
    source: |
        def main(event, context)
        "Hello from Ruby!"
        end
    events:
        hello-http:
        type: http
        metadata:
        path: /ruby
        method: GET

Deploy a simple Ruby HTTP function with Kubeless.

# kubeless/demo/python-cron.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: scheduled-python
    namespace: default
spec:
    runtime: python3.8
    handler: handler.main
    source: |
        def main(event, context):
        print("Scheduled Hello!")
    events:
        schedule-event:
        type: scheduled
        metadata:
        schedule: "*/5 * * * *"

Python function triggered on a schedule using a CronJob.

# kubeless/demo/node-kafka.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: kafka-node
    namespace: default
spec:
    runtime: nodejs14
    handler: handler.main
    source: |
        module.exports.main = (event, context) => {
        console.log('Received Kafka message:', event.body);
        };
    events:
        kafka-event:
        type: kafka
        metadata:
        topic: test-topic
        broker: localhost:9092

Node.js function triggered by a Kafka message.

# kubeless/demo/python-rabbitmq.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: rabbit-python
    namespace: default
spec:
    runtime: python3.8
    handler: handler.main
    source: |
        def main(event, context):
        print("Received RabbitMQ message:", event.body)
    events:
        rabbit-event:
        type: rabbitmq
        metadata:
        exchange: test-exchange
        queue: test-queue

Python function triggered by RabbitMQ messages.

# kubeless/demo/python-cloudevent.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: cloudevent-python
    namespace: default
spec:
    runtime: python3.8
    handler: handler.main
    source: |
        def main(event, context):
        print("CloudEvent received:", event)
    events:
        cloudevent:
        type: cloudevent
        metadata:
        source: /source
        type: com.example.event

Python function triggered by CloudEvents.

# kubeless/demo/python-http-deps.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: http-deps-python
    namespace: default
spec:
    runtime: python3.8
    handler: handler.main
    source: |
        import requests
        def main(event, context):
        r = requests.get('https://httpbin.org/get')
        return r.text
    events:
        hello-http:
        type: http
        metadata:
        path: /requests
        method: GET

Python HTTP function that uses additional dependencies.

# kubeless/demo/node-cron.yaml
apiVersion: kubeless.io/v1beta1
kind: Function
metadata:
    name: scheduled-node
    namespace: default
spec:
    runtime: nodejs14
    handler: handler.main
    source: |
        module.exports.main = (event, context) => {
        console.log('Scheduled Node.js function executed!');
        };
    events:
        schedule-event:
        type: scheduled
        metadata:
        schedule: "0 * * * *"

Node.js function triggered on a schedule using Cron.