Deploying nodejs function to OpenFaas

Installing OpenFaas to minikube

Create a service account for Helm’s server component (tiller):

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

Install tiller which is Helm’s server-side component:

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

Create namespaces for OpenFaaS core components and OpenFaaS Functions:

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

Add the OpenFaaS helm repository

helm repo add openfaas https://openfaas.github.io/faas-netes/

Update all the charts for helm

helm repo update

Generate a random password

export PASSWORD=$(head -c 12 /dev/urandom | shasum| cut -d' ' -f1)

Create a secret for the password

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

Install OpenFaaS using the chart

helm upgrade openfaas --install openfaas/openfaas --namespace openfaas --set functionNamespace=openfaas-fn --set basic_auth=true

Set the OPENFAAS_URL env-var

export OPENFAAS_URL=$(minikube ip):31112

Login using the CLI

echo -n $PASSWORD | faas-cli login -g http://$OPENFAAS_URL -u admin — password-stdin

Creating node function

Login to docker if using docker hub

docker login

Create node function using the faas cli

faas-cli new callme --lang node

Build, Push Docker image and deploy to openFaas

faas-cli build -f callme.yml
faas-cli push -f callme.yml
faas-cli deploy -f callme.yml --gateway $OPENFAAS_URL

or

faas-cli up  -f callme.yml

Invoke function for tests using the cli

faas-cli invoke callme --gateway $OPENFAAS_URL

Invoke function for tests using curl command

curl -XGET http://$OPENFAAS_URL/function/callme

Now let's connect to kafka

Install kafka connector Specify topics separated by a comma and set the borker host according to your kafka broker endpoint

helm repo add openfaas https://openfaas.github.io/faas-netes/

helm upgrade kafka-connector openfaas/kafka-connector \
    --install \
    --namespace openfaas \
    --set topics="mytopic" \
    --set broker_host="192.168.99.101:29092" \
    --set print_response="true" \
    --set print_response_body="true"

Modify callme.yml by adding annotation to function

 annotations:
      topic: mytopic

Visualize logs

kubectl logs -n openfaas deploy/kafka-connector -f

Send messages to topic in order to validate trigger

.\kafka-console-producer.bat --broker-list 192.168.99.101:29092 --topic mytopic

Ressources

https://medium.com/faun/getting-started-with-openfaas-on-minikube-634502c7acdf

https://blog.alexellis.io/quickstart-openfaas-cli/

https://www.openfaas.com/blog/kafka-connector/