openfaas

OpenFaaS - Serverless Functions Made Simple

OpenFaaS (Functions as a Service) is a framework for building serverless functions with Docker and Kubernetes which has first class support for metrics. Any process can be packaged as a function enabling you to consume a range of web events without repetitive boiler-plate coding.

Highlights

• Ease of use through UI portal and one-click install
• Write functions in any language for Linux or Windows and package in Docker/OCI image format
• Portable - runs on existing hardware or public/private cloud - Kubernetes and Docker Swarm native
• CLI available with YAML format for templating and defining functions
• Auto-scales as demand increases

Deploy OpenFaaS

Note: You must also pass --set rbac=false if your cluster is not configured with role-based access control. For further information, see here.

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We recommend creating two namespaces, one for the OpenFaaS core services and one for the functions:

$ kubectl apply -f https://raw.githubusercontent.com/openfaas/faas-netes/master/namespaces.yml

You will now have openfaas and openfaas-fn. If you want to change the names or to install into multiple installations then edit namespaces.yml from the faas-netes repo.

Add the OpenFaaS helm chart:

$ helm repo add openfaas https://openfaas.github.io/faas-netes/
"openfaas" has been added to your repositories

Now deploy OpenFaaS from the helm chart repo:

$ helm repo update \
 && helm upgrade openfaas --install openfaas/openfaas \
    --namespace openfaas  \
    --set functionNamespace=openfaas-fn

The above command will also update your helm repo to pull in any new releases.

OpenFaaS Operator / CRD controller

If you would like to work with CRDs there is an alternative controller to faas-netes named OpenFaaS Operator which can be swapped in at deployment time. The OpenFaaS Operator is suitable for development and testing and may replace the faas-netes controller in the future. The Operator is compatible with Kubernetes 1.9 or later.

To use it, add the flag: --set operator.create=true when installing with Helm.

faas-netes vs OpenFaaS Operator

The faas-netes controller is the most tested, stable and supported version of the OpenFaaS integration with Kubernetes. In contrast the OpenFaaS Operator is based upon the codebase and features from faas-netes, but offers a tighter integration with Kubernetes through CustomResourceDefinitions. This means you can type in kubectl get functions for instance.

Deploy for development / testing

You can run the following command from within the faas-netes/chart folder in the faas-netes repo.

$ helm upgrade --install openfaas openfaas/ \
   --namespace openfaas \
   --set functionNamespace=openfaas-fn

Exposing services

NodePorts

By default NodePorts will be created for the API Gateway and Prometheus.

LB

If you're running on a cloud such as AKS or GKE you will need to pass an additional flag of --set serviceType=LoadBalancer to tell helm to create LoadBalancer objects instead. An alternative to using multiple LoadBalancers is to install an Ingress controller.

Deploy with an IngressController

In order to make use of automatic ingress settings you will need an IngressController in your cluster such as Traefik or Nginx.

Add --set ingress.enabled to enable ingress pass --set ingress.enabled=true when running the installation via helm.

By default services will be exposed with following hostnames (can be changed, see values.yaml for details):

• faas-netes.openfaas.local
• gateway.openfaas.local
• prometheus.openfaas.local
• alertmanager.openfaas.local

Secure the Gateway administrative API and UI with basic auth

In order to enable basic auth first you need to create a secret named basic-auth in the openfaas namespace:

# 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 

Update the Helm release and enable basic auth with:

helm upgrade --reuse-values openfaas openfaas/openfaas \
    --set basic_auth=true

Save your credentials in faas-cli store:

echo $password | faas-cli login -g http://GATEWAY-URL -u admin --password-stdin

Configuration

Additional OpenFaaS options in values.yaml.

Parameter	Description	Default
operator.create	Use the OpenFaaS operator CRD controller, default uses faas-netes as the Kubernetes controller	false
functionNamespace	Functions namespace	default
async	Deploys NATS	true
exposeServices	Expose NodePorts/LoadBalancer	true
serviceType	Type of external service to use NodePort/LoadBalancer	NodePort
ingress.enabled	Create ingress resources	false
rbac	Enable RBAC	true
faasnetesd.readTimeout	Queue worker read timeout	20s
faasnetesd.writeTimeout	Queue worker write timeout	20s
faasnetesd.imagePullPolicy	Image pull policy for deployed functions	Always
gateway.readTimeout	Queue worker read timeout	20s
gateway.writeTimeout	Queue worker write timeout	20s
gateway.upstreamTimeout	Maximum duration of upstream function call	20s
gateway.scaleFromZero	Enables an intercepting proxy which will scale any function from 0 replicas to the desired amount	false
queueWorker.ackWait	Max duration of any async task/request	30s
openfaasImagePullPolicy	Image pull policy for openfaas components, can change to IfNotPresent in offline env	Always

Specify each parameter using the --set key=value[,key=value] argument to helm install. See values.yaml for detailed configuration.

Removing the OpenFaaS

All control plane components can be cleaned up with helm:

$ helm delete --purge openfaas

Follow this by the following to remove all other associated objects:

$ kubectl delete namespace/openfaas
$ kubectl delete namespace/openfaas-fn

In some cases your additional functions may need to be either deleted before deleting the chart with faas-cli or manually deleted using kubectl delete.