authd_fetch.js

import _fetch from 'fetch'
import Config from '../config/environment';
import Ember from 'ember'

export default Ember.Service.extend({
  session: Ember.inject.service('session'),
  fetch(url, options={}) {
    return new Promise((resolve, reject) => {
      this.get('session').authorize('authorizer:devise', (headerName, headerContent) => {
        options = Object.assign({headers: {}}, options)
        let authHeaders = {}
        authHeaders[headerName] = headerContent
        options["headers"] = Object.assign(options["headers"], authHeaders)
        resolve(_fetch(`${Config.api.host}${url}`, options));
      });
    });
  }
});