util.go

package handler

import (
	"encoding/json"
	"net/http"
	"strings"
	"time"

	"github.com/dchest/authcookie"
	"github.com/drone/drone/pkg/template"
)

// -----------------------------------------------------------------------------
// Rendering Functions

// Renders the named template for the specified data type
// and write the output to the http.ResponseWriter.
func RenderTemplate(w http.ResponseWriter, name string, data interface{}) error {
	w.Header().Add("Content-Type", "text/html; charset=utf-8")
	return template.ExecuteTemplate(w, name, data)
}

// Renders the 404 template for the specified data type
// and write the output to the http.ResponseWriter.
func RenderNotFound(w http.ResponseWriter) error {
	w.Header().Add("Content-Type", "text/html; charset=utf-8")
	w.WriteHeader(http.StatusNotFound)
	return template.ExecuteTemplate(w, "404.amber", nil)
}

// Renders the 403 template for the specified data type
// and write the output to the http.ResponseWriter.
func RenderForbidden(w http.ResponseWriter) error {
	w.Header().Add("Content-Type", "text/html; charset=utf-8")
	w.WriteHeader(http.StatusNotFound)
	return template.ExecuteTemplate(w, "403.amber", nil)
}

// RenderJson renders a JSON representation of resource v and
// writes to the http.ResposneWriter.
func RenderJson(w http.ResponseWriter, data interface{}) error {
	w.Header().Add("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	return json.NewEncoder(w).Encode(data)
}

// RenderText write the plain text string to the http.ResposneWriter.
func RenderText(w http.ResponseWriter, text string, code int) error {
	w.Header().Add("Content-Type", "text/plain")
	w.WriteHeader(code)
	w.Write([]byte(text))
	return nil
}

// RenderError renders a text representation of the Error message.
func RenderError(w http.ResponseWriter, err error, code int) error {
	return RenderText(w, err.Error(), code)
}

// -----------------------------------------------------------------------------
// Cookie Helper functions

// SetCookie signs and writes the cookie value.
func SetCookie(w http.ResponseWriter, r *http.Request, name, value string) {
	sec := IsHttps(r)
	str := authcookie.New(value, time.Now().Add(time.Hour*24), secret)
	cookie := http.Cookie{
		Name:     name,
		Value:    str,
		Path:     "/",
		Domain:   r.URL.Host,
		HttpOnly: true,
		Secure:   sec,
	}

	http.SetCookie(w, &cookie)
}

func IsHttps(r *http.Request) bool {
	if r.URL.Scheme == "https" {
		return true
	}
	if strings.HasPrefix(r.Proto, "HTTPS") {
		return true
	}
	if r.Header.Get("X-Forwarded-Proto") == "https" {
		return true
	}
	return false
}

// GetCookie retrieves and verifies the signed cookie value.
func GetCookie(r *http.Request, name string) string {
	cookie, err := r.Cookie(name)
	if err != nil {
		return ""
	}
	return authcookie.Login(cookie.Value, secret)
}

// DelCookie deletes a secure cookie.
func DelCookie(w http.ResponseWriter, r *http.Request, name string) {
	cookie := http.Cookie{
		Name:   name,
		Value:  "deleted",
		Path:   "/",
		Domain: r.URL.Host,
		MaxAge: -1,
	}

	http.SetCookie(w, &cookie)
}