Learning Knative - Quickstart

Local Knative dev environment

• Kourier or Istio
• Kafka or in-memory broker
• Kind or K3D
• Loki observability

Introduction

The outcome of this exercise is a setup where services written in multiple languages get auto-scaled as cloudevents arrive.

Prerequisites

Kubernetes Distro

This project provides scripts for setting up Knative using either of the following distros

• Kind
• k3d

Apple Mac OSX

• Docker for Mac
• Correctly configured Docker for Mac instance
  • At least 3 CPUs
  • At least 5 GB of RAM
• Kubernetes development tools

  brew install kubectl
  brew install kind
  brew install k3d
  brew install istioctl
  brew install helm

Linux

• Docker

  yay docker

• Kubernetes development tools

  yay kubectl
  yay kind
  yay rancher-k3d-bin
  yay istio
  yay helm

Getting started

Select Kubernetes Distro

• Kind

  ./local/dev-kind
  

• k3ds

  ./local/dev-k3ds
  

Examples

1. Install example App

   kubectl apply -f ./examples/services.yaml
   ./examples/triggers
   kubectl wait ksvc node-service --for=condition=Ready

2. Browser to the example Node Site http://node-service.default.127.0.0.1.nip.io/

3. Post to example site

   curl -v "http://node-service.default.127.0.0.1.nip.io" -d '{}'

4. Watch event triggered containers auto-scale

   kubectl get pods
   kubectl logs -l serving.knative.dev/service=rust-service -c user-container -f
   [2020-08-21T20:23:42Z INFO  rust_service] Starting rust-service
   [2020-08-21T20:23:42Z INFO  actix_server::builder] Starting 1 workers
   [2020-08-21T20:23:42Z INFO  actix_server::builder] Starting "actix-web-service-127.0.0.1:9000" service on 127.0.0.1:9000
   [2020-08-21T20:23:56Z INFO  rust_service] Event Data Example { sequence: 99, message: "hello from node-service - Handled by 0 - hello from go-service" }

5. Inspect monitoring dashboard

   5.1 Start kubectl proxy

   kubectl port-forward --namespace knative-monitoring \
   $(kubectl get pods --namespace knative-monitoring \
   --selector=app=grafana --output=jsonpath="{.items..metadata.name}") \
   3000

   5.2 Browse to Grafana http://localhost:3000/

Performance Results from sample application

Node Service

Python Service

Golang Service

Rust service