OpenFaaS examples

This guide requires docker, kubectl, faas-cli and k3d to be installed. Steps on how to install k3d and faas-cli are provided in this guide.

TL;DR

Requires docker, kubectl, faas-cli and k3d.

See next step on how to install k3d and faas-cli.

./setup.sh

Install k3d and faas-cli

Install k3d's cli that is a little helper to run Rancher Lab's k3s in Docker.

k3s is a lightweight Kubernetes distribution, 5 times less than k8s.

curl -s https://raw.githubusercontent.com/rancher/k3d/master/install.sh | TAG=v1.3.2 bash

Install faas-cli.

curl -sSL https://cli.openfaas.com | sudo sh

Create cluster

Create a cluster with 3 workers and expose a NodePort on worker-0 at 8080.

k3d create --publish 8080:8080@k3d-k3s-default-worker-0 --workers 3

Install OpenFaaS

1.0 Create namespaces

kubectl apply -f namespaces.yml

2.0 Create password

Generate secrets so that we can enable basic authentication for the gateway:

kubectl -n openfaas create secret generic basic-auth \
--from-literal=basic-auth-user=admin \
--from-literal=basic-auth-password=admin

For better security generate a random password

# generate a random password
PASSWORD=$(head -c 12 /dev/urandom | shasum| cut -d' ' -f1)

kubectl -n openfaas create secret generic basic-auth \
--from-literal=basic-auth-user=admin \
--from-literal=basic-auth-password="$PASSWORD"

3.0 Apply YAML files

kubectl apply -f ./setup/

4.0 Log in

Now log-in:

faas login --password admin

# or

echo -n $PASSWORD | faas-cli login --password-stdin

List the current functions deployed

faas list

Function                        Invocations     Replicas

Deploying a demo function

Build the function

faas build -f ./hello-python.yml

You can check the image by listing the docker images

docker images | grep hello-python

Import the local docker image from our local docker daemon into the cluster

k3d i hello-python:latest
# or
k3d import-images hello-python:latest

Deploy the function

faas deploy -f hello-python.yml

List the functions

faas list

Test the function

curl 127.0.0.1:8080/function/hello-python -d "Demo"

Creating my first function

OpenFaas provides a lot of premade templates:

template/
├── csharp
├── csharp-armhf
├── dockerfile
├── dockerfile-armhf
├── go
├── go-armhf
├── java12
├── java8
├── node
├── node-arm64
├── node-armhf
├── php7
├── python
├── python3
├── python3-armhf
├── python-armhf
└── ruby

For instance to create a nodejs function simply run

faas-cli new myfirst --lang node

Repeat the previous section on how to deploy it, here's an example of a nodejs handler function:

module.exports = (context, callback) => {
  callback(undefined, { status: 'done' })
}