Creating a function

Starting state: You have installed the selected func release and have a text editor. Work in a writable directory that does not already contain a hello-function project. No cluster is needed for this lesson.

Create a Go HTTP project

Use a different name from Quickstart's hello Service, so later deployment does not overwrite that exercise:

func create --language go --template http hello-function

Expected result

func reports that it created a Go function in hello-function. The new directory contains generated source, tests, and func.yaml project configuration.

Write a recognizable response

Open hello-function/function.go. In the selected release's generated MyFunction.Handle method, find:

fmt.Fprintln(res, "OK")

Replace only that line with:

fmt.Fprintln(res, "Hello from Knative Functions!")

The resulting handler is:

func (f *MyFunction) Handle(res http.ResponseWriter, req *http.Request) {
    fmt.Fprintln(res, "Hello from Knative Functions!")
}

Save the file. Keep the rest of the generated file, imports, constructor, project configuration, and tests unchanged. This handler writes a fixed HTTP response; it does not process a CloudEvent or subscribe to a Broker. The next lesson runs it and checks the response you just chose.

If the generated method differs, stop and check your CLI release against installation and the selected Go HTTP template source. Do not replace an unfamiliar file wholesale with this excerpt.

Other languages and command forms belong in creating functions. Exact options remain in the func create command reference.

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