mstar-webserver/main.go

package main

import (
	"embed"
	"fmt"
	"html/template"
	"net/http"
	"os"

	"github.com/sirupsen/logrus"
	"gitlab.com/mstarongitlab/weblogger"
)

const HTML_PREFIX = "<!-- "
const HTML_SUFFIX = " -->"

//go:embed templates
var embed_templates embed.FS

//go:embed static
var embed_static embed.FS

//go:embed well-known
var embed_well_known embed.FS

// go: embed robots.txt
var embed_robots_txt string

// go: embed humans.txt
var embed_humans_txt string

func main() {
	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}
	logrus.WithField("port", port).Info("starting server")

	// Custom-ish paths. Includes templates
	http.HandleFunc("/", handleRoot)

	// Funny awawawa stream
	http.HandleFunc("/cat/awawawa", awawaStream)

	// static files in /static
	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(embed_static))))

	// .well-known from /well-known
	http.Handle("/.well-known/", http.StripPrefix("/.well-known/", http.FileServer(http.FS(embed_well_known))))

	// Static files not in /static or /.well-known
	http.HandleFunc("/robots.txt", buildHTTPFileReader(embed_robots_txt))
	http.HandleFunc("/humans.txt", buildHTTPFileReader(embed_humans_txt))

	default_mux := http.DefaultServeMux
	logger := weblogger.LoggingMiddleware(default_mux)

	if err := http.ListenAndServe(":"+port, logger); err != nil {
		logrus.WithField("event", "stop server").Fatal(err)
	}
}

func handleRoot(w http.ResponseWriter, r *http.Request) {
	// logRequestInfo(r)
	tmpl, err := template.ParseFS(embed_templates, "templates/index.html")
	if err != nil {
		http.Error(w, "Couldn't parse template file", http.StatusInternalServerError)
		return
	}
	err = tmpl.Execute(w, nil)
	if err != nil {
		http.Error(w, "Failed to execute template", http.StatusInternalServerError)
	}
}

func buildHTTPFileReader(embed_content string) func(w http.ResponseWriter, r *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		// logRequestInfo(r)
		fmt.Fprintf(w, "%s", embed_content)
	}
}

func awawaStream(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html")
	w.WriteHeader(206)
	w.Header().Set("Status", "206")
	genStub(1024, w) // Hardcoded. Firefox & Chrome both have this value and a len of 0 wouldn't work
	fmt.Println("Starting awawawa stream")
	i := 0
	for {
		select {
		case <-r.Context().Done():
			fmt.Println("awawawa Stream done")
			return
		default:
			if i%2 == 0 {
				fmt.Fprint(w, "a")
			} else {
				fmt.Fprint(w, "w")
			}
			i += 1
		}
	}
}

func genStub(length int, w http.ResponseWriter) {
	PreSufLen := len(HTML_PREFIX) + len(HTML_SUFFIX)
	fmt.Fprint(w, HTML_PREFIX)
	for i := 0; i < length-PreSufLen; i++ {
		fmt.Fprint(w, '\u0020')
	}
	fmt.Fprint(w, HTML_SUFFIX)
}