Golang CORS Proxy Server (Example)

server.go

package main

import (
	"net/http"
	"encoding/json"
	"github.com/unrolled/render"
)

const (
	GITHUB_API_REPOS string = "https://api.github.com/users/wpioneer/repos"
)

type Repos struct {
	Name        string `json:"name"`
	Description string `json:"description"`
}

func getJson(this interface{}, url string) error {
	res, err := http.Get(url)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	return json.NewDecoder(res.Body).Decode(this)
}

func setDefaultHeaders(w http.ResponseWriter) {
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Methods", "GET")
	w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, post-check=0, pre-check=0")
	w.Header().Set("Content-Type", "application/json; charset=UTF-8")
	w.Header().Set("Vary", "Accept-Encoding")
}

func main() {
	render := render.New()
	mux := http.NewServeMux()

	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		setDefaultHeaders(w)

		repos := new([]Repos)

		url := GITHUB_API_REPOS
		getJson(repos, url)

		render.JSON(w, http.StatusOK, repos)
	})

	http.ListenAndServe(":8000", mux)
}