hello-world

Sample Function Java

Prerequisites

OpenFunction

You can refer to the Installation Guide to setup OpenFunction.

Run it locally

Build the function locally

pack build func-http-java --path ../ --builder openfunction/builder-java:v2-18 --env FUNC_NAME="dev.openfunction.samples.HttpFunctionImpl"  --env FUNC_CLEAR_SOURCE=true

Run the function

docker run --rm --env="FUNC_CONTEXT={\"name\":\"HelloWorld\",\"version\":\"v1.0.0\",\"port\":\"8080\",\"runtime\":\"Knative\"}" --env="CONTEXT_MODE=self-host" --name func-http-java -p 8080:8080 func-http-java

Send a request

curl http://localhost:8080/
# Hello World

Deployment

1. Create secret

Follow this guide to create a registry credential.

2. Create function

For sample function below, modify the spec.image field in function-sample.yaml to your own container registry address:

apiVersion: core.openfunction.io/v1beta1
kind: Function
metadata:
  name: function-http-java
spec:
  image: "<your registry name>/sample-java-func:v1"

Use the following command to create this Function:

kubectl apply -f function-sample.yaml

3. Access function

You can observe the process of a function with the following command:

kubectl get functions.core.openfunction.io
 
NAME                 BUILDSTATE   SERVINGSTATE   BUILDER         SERVING         ADDRESS                                                         AGE
function-http-java   Succeeded    Running        builder-jgnzp   serving-q6wdp   http://function-http-java.default.svc.cluster.local/               22m

The Function.status.addresses field provides various methods for accessing functions. Get Function addresses by running following command:

kubectl get function function-http-java -o=jsonpath='{.status.addresses}'

You will get the following address:

[{"type":"External","value":"http://function-http-java.default.ofn.io/"},
{"type":"Internal","value":"http://function-http-java.default.svc.cluster.local/"}]

You can use the following command to create a pod in the cluster and access the function from the pod:

kubectl run curl --image=radial/busyboxplus:curl -i --tty

Access functions by the internal address:

curl http://function-http-java.default.svc.cluster.local
Hello, World!

Access functions by the external address:

To access the function via the Address of type External in Funtion.status, you should configure local domain first, see Configure Local Domain.

curl http://function-http-java.default.ofn.io
Hello, World!