OpenFaaS Golang HTTP template

This template provides additional context and control over the HTTP response from your function.

Status of the template

This template is pre-release and is likely to change - please provide feedback via https://github.com/openfaas/faas

The template makes use of the OpenFaaS incubator project of-watchdog.

Trying the template

$ faas template pull https://github.com/openfaas-incubator/golang-http-template
$ faas new --lang golang-http <fn-name>

Example usage

Example writing a successful message:

package function

import (
	"fmt"
	"net/http"

	"github.com/openfaas-incubator/go-function-sdk"
)

// Handle a function invocation
func Handle(req handler.Request) (handler.Response, error) {
	var err error

	message := fmt.Sprintf("Hello world, input was: %s", string(req.Body))

	return handler.Response{
		Body:       []byte(message),
    }, err
}

Example writing a custom status code

package function

import (
	"fmt"
	"net/http"

	"github.com/openfaas-incubator/go-function-sdk"
)

// Handle a function invocation
func Handle(req handler.Request) (handler.Response, error) {
	var err error

	return handler.Response{
		Body:       []byte("Your workload was accepted"),
		StatusCode: http.StatusAccepted,
	}, err
}

Example writing an error / failure.

package function

import (
	"fmt"
	"net/http"

	"github.com/openfaas-incubator/go-function-sdk"
)

// Handle a function invocation
func Handle(req handler.Request) (handler.Response, error) {
	var err error

	return handler.Response{
        Body: []byte("the input was invalid")
	}, fmt.Errorf("invalid input")
}

The error will be logged to stderr and the body will be written to the client along with a HTTP 500 status code.

Example reading a header.

package function

import (
	"log"

	"github.com/openfaas-incubator/go-function-sdk"
)

// Handle a function invocation
func Handle(req handler.Request) (handler.Response, error) {
	var err error

	log.Println(req.Header) // Check function logs for the request headers

	return handler.Response{
		Body: []byte("This is the response"),
		Header: map[string][]string{
			"X-Served-By": []string{"My Awesome Function"},
		},
	}, err
}