config.js

const simpleOauthModule = require("simple-oauth2");
const randomstring = require("randomstring");

const oauthProvider = process.env.OAUTH_PROVIDER || "github";
const loginAuthTarget = process.env.AUTH_TARGET || "_self";

const oauth2 = simpleOauthModule.create({
  client: {
    id: process.env.OAUTH_CLIENT_ID,
    secret: process.env.OAUTH_CLIENT_SECRET
  },
  auth: {
    // Supply GIT_HOSTNAME for enterprise github installs.
    tokenHost: process.env.GIT_HOSTNAME || "https://github.com",
    tokenPath: process.env.OAUTH_TOKEN_PATH || "/login/oauth/access_token",
    authorizePath: process.env.OAUTH_AUTHORIZE_PATH || "/login/oauth/authorize"
  }
});

const originPattern = process.env.ORIGIN || "";
if ("".match(originPattern)) {
  console.warn(
    "Insecure ORIGIN pattern used. This can give unauthorized users access to your repository."
  );
  if (process.env.NODE_ENV === "production") {
    console.error("Will not run without a safe ORIGIN pattern in production.");
    process.exit();
  }
}

const authorizationUri = oauth2.authorizationCode.authorizeURL({
  redirect_uri: process.env.REDIRECT_URL,
  scope: process.env.SCOPES || "repo,user",
  state: randomstring.generate(32)
});

module.exports = {
  oauth2,
  authorizationUri,
  originPattern,
  oauthProvider,
  loginAuthTarget
};