sample-apps/go/server/main.go

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

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

func remoteHello(nextServer string) string {
	resp, err := http.Get(nextServer)
	if err != nil {
		log.Fatal(err)
	}
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}
	err = resp.Body.Close()
	if err != nil {
		log.Fatal(err)
	}
	return string(body)
}

func hello(w http.ResponseWriter, _ *http.Request) {
	url, exists := os.LookupEnv("NEXT_SERVER")
	if !exists {
		fmt.Fprintf(w, "hello\n")
	} else {
		fmt.Fprintf(w, "%s\n", remoteHello(url))
	}
}

func main() {
	http.HandleFunc("/hello", hello)
	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		log.Fatal(err)
	}
}