This repo provides a simple Hello web app based on Spring Boot and Spring Cloud Function.

It can be deployed as a standalone web app, as a Tanzu Application Platform workload resource or, as a Kubernetes Deployment and Service.

NOTE: The project is configured for Java 11, if you prefer a different version, then modify the java.version property in pom.xml.

The project contains the following Spring Cloud Function bean definition:

	@Bean
	public Function<String, String> hello() {
		return (in) -> {
			return "Hello " + in;
		};
	}

This simple function returns the input value, prefixed with "Hello ". This is just a simple example what a Spring Cloud Function can do. It is defined in src/main/java/com/example/helloapp/HelloAppApplication.java

This app can be deployed as a stand-alone web app, as a Tanzu Application Platform (TAP) workload resource or, as a Kubernetes Deployment and Service.

You can build the project using Maven:

mvn clean package

To run the app using the embedded Tomcat server you can run this command:

mvn spring-boot:run

You can access the function using curl:

curl -w'\n' -H 'Content-Type: text/plain' localhost:8080 -d "Fun"

NOTE: The provided config/workload.yaml file uses the Git URL for this sample. When you want to modify the source, you must push the code to your own Git repository and then update the spec.source.git information in the config/workload.yaml file.

You can containerize this template app and deploy it as a Tanzu Application Platform (TAP) workload. You need to have TAP installed on your cluster. See the VMware Tanzu Application Platform documentation for details.

We have included a Tiltfile file to make this easier when deploying to a cluster.

For best results use Tilt version v0.23.2 or later. You can install Tilt by following these instructions: https://docs.tilt.dev/install.html

To set up the deployment environment set the CURRENT_CONTEXT environment variable.

Set CURRENT_CONTEXT using:

export CURRENT_CONTEXT=$(kubectl config current-context)

To build and deploy the app run:

tilt up

and follow the instructions (hitting space bar brings up the Tilt interface in your browser).

To uninstall the app run:

tilt down

If you don't have curl installed it can be installed using downloads here: https://curl.se/download.html

Determine the URL to use for the accessing the app by running:

tanzu apps workload get hello-fun

To invoke the deployed function run the following curl command in another terminal window:

curl <URL> -w'\n' -H 'Content-Type: text/plain' -d Fun

This depends on the TAP installation having DNS configured for the Knative ingress.

If you make modifications to the source and push to your own Git repository, then you can update the spec.source.git information in the config/workload.yaml file.

When you are done developing your function app, you can simply deploy it using:

tanzu apps workload apply -f config/workload.yaml

If you would like deploy the code from your local working directory you can use the following command:

tanzu apps workload create hello-fun -f config/workload.yaml \
  --local-path . \
  --source-image <REPOSITORY-PREFIX>/hello-fun-source \
  --type web