Angular 4 JWT Authorization Bearer

http.interceptor.ts

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { HttpClient, HttpHeaders, HttpInterceptor, HttpHandler, HttpRequest, HttpEvent } from '@angular/common/http';
import { Post } from './content/post';

@Injectable()
export class CchainHttpInterceptor implements HttpInterceptor {

    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

        // if it is a Github API request
        if (req.url.includes('localhost') && !req.url.includes('login')) {
            // we need to add an OAUTH token as a header to access the Github API
            var token = localStorage.getItem('KEY');
            const clone = req.clone({
                setHeaders: {
                    'Authorization': "Bearer " + token
                }
            });
            return next.handle(clone);
        }
        // if it's not a Github API request, we just handle it to the next handler
        return next.handle(req);
    }

}