OpenFaaS on Minikube

18 Nov 2017 ⋅FaaS ⋅kubernetes ⋅serverless ⋅code-example

Minimal steps to run serveless/functions-as-a-service platform on Minikube.

Start minikube.
```
minikube start
```
Install helm, if you haven’t already.
```
brew install kubernetes-helm
```
Install openfass CLI.
```
brew install faas-cli
```

Create a new service account for Helm. We are calling it tiller.

kubectl -n kube-system create sa tiller \
 && kubectl create clusterrolebinding tiller \
 — clusterrole cluster-admin \
 — serviceaccount=kube-system:tiller

Start helm.

helm init --skip-refresh --upgrade --service-account tiller

Get openfass kubernetes integration.

git clone https://github.com/openfaas/faas-netes && cd faas-netes

Install openfass on Kubernetes.

helm upgrade — install --debug --reset-value --set async=false --set rbac=false openfaas openfaas/

At this point you should see that kubernetes has deployed our serverless infrastructure.

kubectl get pods

NAME                            READY     STATUS    RESTARTS   AGE
alertmanager-2526763497-qxzwb   1/1       Running   0          43m
faas-netesd-1969965387-mtfn3    1/1       Running   0          43m
gateway-640487255-5k2xr         1/1       Running   0          43m
hello-4272447001-lkxcs          1/1       Running   0          22m
prometheus-3793543547-w13ln     1/1       Running   0          43m

You can also look at the the ui

minikube service gateway-external

Now, that we have infrastructure, lets build and deploy a python hello world function.
```
faas-cli new --lang python hello
```
This will create hello.yml, hello/handler.py and hello/requirements.txt. hello.yml describes the deployment (service name, image to be used etc.). You want to change the image from hello to <your_docker_id>/hello
```
provider:
  name: faas
  gateway: http://localhost:8080
functions:
  hello:
    lang: python
    handler: ./hello
    image: dharmeshkakadia/hello
```
hello/handler.py has the code to handle request. In our case it just prints back the string.
```
def handle(st):
    print(st)
```
The requirements file is empty since we don’t have any dependencies right now.
Lets build our code, docker image and push it to registry. We will use docker with Kubernetes for this purpose.
```
eval $(minikube docker-env)
docker login
faas-cli build -f hello.yml
faas-cli push -f hello.yml
```

Deploy the hello function service.

faas-cli deploy -f hello.yml --gateway $(minikube service gateway-external  --url)

At this point you should be seeing the service is deployed

Deploying: hello.
No existing function to remove
Deployed.
URL: http://192.168.64.4:31112/function/hello
202 Accepted

You can confirm it in UI as well.

You are now ready to test the service. You can invoke it from UI, via REST api or through CLI.

echo world | faas-cli invoke hello --gateway $(minikube service gateway-external  --url)

The UI will show the invocation count has changed. You can also confirm it through CLI.
The Prometheus dashboard also has the metrics for the service. Here is the dashboard showing invocation count.
```
minikube service prometheus-external
```
Finally you can remove the hello function with
```
faas-cli remove hello --gateway $(minikube service gateway-external  --url)
```
Thats it ! OpenFaaS looks a great platform. Give it a try !

@dharmeshkakadia

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