Serverless + Kubeless Guide

This document serves as a guide to setting up servless with serveless-kubeless plugin. The guide provides instructions to configuring and running a sample application from start to finish; showcasing various functionality serverless-kubeless supports.

Demos

kubeless functions
serveless framework
serverless calling kubeless function
serverless cron using kubeless scheduler
serverless rest endpoint using kubeless|kubernetes proxy
serverless packaging
serverless using typescript plugin
TODO chained functions
TODO backoff retry to external API
TODO roles

Kubeless Setup

Install Minikube

$ brew cask install virtualbox
$ brew install minikube
$ minikube start --vm-driver=virtualbox
$ kubectl config use-context minikube

Switching context: You can switch context for kubernetes using use-context for example using docker-for-desktop instead of minikube

$ kubectl config get-contexts
$ kubectl config use-context docker-for-desktop

Install kubeless to the cluster

# Generate configmap

$ export RELEASE=$(curl -s https://api.github.com/repos/kubeless/kubeless/releases/latest | grep tag_name | cut -d '"' -f 4)
$ kubectl create ns kubeless
$ kubectl create -f https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless-$RELEASE.yaml

Install kubeless cli tool on unix machines

$ export OS=$(uname -s| tr '[:upper:]' '[:lower:]')

$ curl -OL https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless_$OS-amd64.zip && \
  unzip kubeless_$OS-amd64.zip && \
  sudo mv bundles/kubeless_$OS-amd64/kubeless /usr/local/bin/

# Check to see if kubeless is installed
$ kubectl get pods -n kubeless

Serverless Setup, Deploying, and Running

$ npm i serverless -g
$ git clone <this project>
$ cd string-transform-kubeless
$ serverless login
$ npm install
$ serverless deploy -v
$ kubeless function ls -n kubeless
$ serverless invoke reverse -data 'hello world' -l

Gotchas

Not all of the functions provided by serverless-kubeless plugin is working and there are some minor annoyances present. See the notes below for details.

In the serverless.yml file serverless-kubeless function names cannot be camelcased or snake case must use lowercase, periods and hypens only.
serverless-kubeless doesn't like it when you nest functions: src/function/handler.ts. Try to keep files flat and in root.
Deploying with dependencies is currently not working. Functions deployed with dependencies results into a status of NOT READY. See packaging in serveless.yml
Chained sequences is currently not working. See functions in serverless.yml

Reading resources

Kubenetes using Docker (Docker-For-Desktop)

If you are running docker locally and prefer to use kubernetes with docker over minikube; you can install kubernetes via docker > preferences > kubernetes > install

Enable docker-for-desktop dashboad

$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml

View docker-for-desktop browser dashboad

$ kubectl proxy

Kubeless cheat sheet

# List functions
kubeless function ls

# List functions using namespace
kubeless function ls -n kubeless

# Call function
kubeless function call <function> --data <data>

# Log function
kubeless function logs <function>

# Describe function
kubeless function describe <function>

# Update function
kubeless function update <function> --from-file <file>

# Delete function
kubeless function delete <function>

# Hitting a kubeless function using curl
kubectl proxy -p 8080 & curl -L --data '{"Another": "Echo"}' \
  --header "Content-Type:application/json" \
  localhost:8080/api/v1/namespaces/default/services/hello:http-function-port/proxy/
{"Another": "Echo"}

randyyaj/serverless-kubeless-demo