config.json

{
    "discord_token": "Bot TOKENHERE",
    "github_user": "YOURUSERNAMEHERE",
    "github_token": "TOKENHERE",
    "repo": "TARGETREPOHERE"
}

main.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
	"time"

	"github.com/bwmarrin/discordgo"
)

type (
	config struct {
		DiscordToken string `json:"discord_token"`
		GithubUser   string `json:"github_user"`
		GithubToken  string `json:"github_token"`
		Repo         string `json:"repo"`
	}

	request struct {
		Title string `json:"title"`
		Body  string `json:"body"`
	}

	response struct {
		HTMLURL string `json:"html_url"`
	}
)

var (
	conf   config
	sess   *discordgo.Session
	client = &http.Client{Timeout: 20 * time.Second}
)

func submitIssue(name, body string) (string, error) {
	var buf bytes.Buffer
	err := json.NewEncoder(&buf).Encode(request{name, body})
	if err != nil {
		return "", err
	}
	req, err := http.NewRequest("POST", fmt.Sprintf("https://api.github.com/repos/%s/issues", conf.Repo), bytes.NewReader(buf.Bytes()))
	if err != nil {
		return "", err
	}
	req.SetBasicAuth(conf.GithubUser, conf.GithubToken)
	rsp, err := client.Do(req)
	if err != nil {
		return "", err
	}
	defer rsp.Body.Close()
	if rsp.StatusCode != 201 {
		raw, err := ioutil.ReadAll(rsp.Body)
		if err != nil {
			return "", err
		}
		return "", fmt.Errorf("Issue while making an issue: %s", string(raw))
	}
	var resp response
	err = json.NewDecoder(rsp.Body).Decode(&resp)
	if err != nil {
		return "", err
	}
	return resp.HTMLURL, nil
}

func handleMessages(s *discordgo.Session, m *discordgo.MessageCreate) {
	if !strings.HasPrefix(m.Content, "!issue") {
		return
	}
	content := strings.SplitN(strings.TrimSpace(strings.TrimPrefix(m.Content, "!issue")), "|", 2)

	if len(content) != 2 {
		s.ChannelMessageSend(m.ChannelID, fmt.Sprintf("Invalid argument count '%d', expected 2.", len(content)))
		return
	}

	result, err := submitIssue(strings.TrimSpace(content[0]), strings.TrimSpace(content[1]))
	if err != nil {
		s.ChannelMessageSend(m.ChannelID, err.Error())
		return
	}
	s.ChannelMessageSend(m.ChannelID, fmt.Sprintf("Your issue has been created: %s", result))
}

func init() {
	file, err := os.Open("config.json")
	if err != nil {
		log.Fatal(err)
	}
	err = json.NewDecoder(file).Decode(&conf)
	if err != nil {
		log.Fatal(err)
	}
}

func main() {
	sess, err := discordgo.New(conf.DiscordToken)
	if err != nil {
		log.Fatal(err)
	}

	sess.AddHandler(handleMessages)

	err = sess.Open()
	if err != nil {
		log.Fatal(err)
	}

	log.Print("Bot is now running.")
	<-make(chan struct{})
}