Feature - buildpack support in faas-cli build

[alexellis]

Description

Feature - buildpack support in faas-cli build

Context

DigitalOcean's AppPlatform, Cloudrun, Heroku, Cloudfoundary, Waypoint all support buildpacks

build packs can generally be inferred automatically, and don't need a Dockerfile

An example for Golang would be the follow:

package main

import (
	"log"
	"net/http"
	"os"
)

func main() {

	port := "8080"
	if val, _ := os.LookupEnv("PORT"); len(val) > 0 {
		port = val
	}

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("Invoked"))
	})
	http.HandleFunc("/_/healthz", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("OK"))
	})

	log.Printf("listening on %s\n", port)
	err := http.ListenAndServe(":"+port, nil)
	if err != nil {
		panic(err)
	}
}

An example of building this would be:

pack build go-mod --builder gcr.io/buildpacks/builder:v1

We could generate this command like we do for faas-cli build. The push and deploy commands would stay the same.

The format for specifying a build pack could be the following where the lang is a buildpack builder i.e. gcr.io/buildpacks/builder:v1 - the / is how we can determine to run pack build instead of docker build

version: 1.0
provider:
  name: openfaas
  gateway: http://127.0.0.1:8080
functions:
  go-mod-app:
    lang: gcr.io/buildpacks/builder:v1
    handler: ./go-mod-app
    image: go-mod-app:latest

I don't see much for us to lose by trying this out as an experiment, if it doesn't get traction, and becomes a burden then it can be removed.

[alexellis]

@yankeexe can you please ask upstream about an ARM release binary on "pack"? cc alexellis/arkade#231

[yankeexe]

@alexellis Link to issue: buildpacks/pack#907

[alexellis]

Closing due to lack of interest from community.