创建一个 Issuer 实例，用于配置 Server 信息。

Issuer Http 配置

Issuer.defaultHttpOptions = { retries: 5, timeout: 15000 };

为防止网络质量影响 RP 与 OP 通信， 可以在Issuer defaultHttpOptions 设置重试次数（retries）和响应时间（timeout）。

动态配置

const Issuer = require('openid-client').Issuer;
Issuer.discover('https://accounts.cloudtrust.com.cn') // => Promise 
  .then(function (issuer) {
    console.log('Discovered issuer %s', issuer);
  });

静态配置

const Issuer = require('openid-client').Issuer;
const issuerUrl = 'https://accounts.cloudtrust.com.cn';
const issuer = new Issuer({
  issuer: issuerUrl,
  authorization_endpoint: `${issuerUrl}/auth`,
  end_session_endpoint: `${issuerUrl}/session/end`,
  token_endpoint: `${issuerUrl}/token`,
  userinfo_endpoint: `${issuerUrl}/me`,
  jwks_uri: `${issuerUrl}/certs`,
  revocation_endpoint: `${issuerUrl}/token/revocation`,
});