Angular is not sending the Cookie received in Set-Cookie even if withCredentials is true

Finally I was able to find the issue. The journey was more satisfying than the result so let me break it down into the steps I took to solve my problem.

In summary, This wansn't an issue with Angular. The cookie I was sending had secureCookie flag on. As I was testing my application without https, it seems that the angular application was not using (or getting access to) the Set-Cookie header received in 200 OK.

My initial code to send the sign in request to the server and handling its response was

  return this.http.post(this.SIGNIN_USER_URL,body,httpOptions)
      .map(response=>{
        console.log('response from backend service',response);
        let result= <ServerResponse>response; 
        console.log("result is "+result.result+' with additional information '+result.additionalInformation)
        return result;
      })
      .catch(this.handleError);

I wasn't using observe: 'response' option which meant that the response would only contain body, not headers. I changed the code to following so that I could see which headers are being received.

const httpOptions = {
  headers: new HttpHeaders({ 'Content-Type': 'application/json' }),
 
withCredentials: true, 
observe: 'response' as 'response'
};  

public signinUser(user:UserSigninInfo):any{
    console.log('contacting server at '+this.API_URL +this.SIGNIN_USER_URL +" with user data "+user+ " with httpOptions "+httpOptions.withCredentials + ","+httpOptions.headers ); 

    let signinInfo= new UserSignin(user);
    let body = JSON.stringify(signinInfo);
    return this.http.post(this.SIGNIN_USER_URL,body,httpOptions)
      .catch(this.handleError);
  }

The above code was being called as follows. I change that to get the headers in the response

return this.bs.signinUser(user).subscribe((res:HttpResponse<any>)=>{console.log('response from server:',res);
  console.log('response headers',res.headers.keys())
} );

I also created an intercepter to print the incoming and outgoing messages (copied from SO)

import {HttpEvent, HttpHandler, HttpInterceptor, HttpRequest, HttpResponse} from "@angular/common/http";
import {Injectable} from "@angular/core";
import {Observable} from "rxjs/Observable";
import 'rxjs/add/operator/do';

@Injectable()
export class CustomInterceptor implements HttpInterceptor {

  constructor() {
  }

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

    console.log("outgoing request",request);
    request = request.clone({
      withCredentials: true
    });
    console.log("new outgoing request",request);

    return next
      .handle(request)
      .do((ev: HttpEvent<any>) => {
        console.log("got an event",ev)
        if (ev instanceof HttpResponse) {
          console.log('event of type response', ev);
        }
      });
  }
}

When I started debugging, I noticed that though the server was sending 10 headers, only 9 were getting printed

headers from server

Print message on console (Set-Cookie was missing! The header my application needed to get authentication cookie)

0: "Content-Length"
​
1: "Content-Security-Policy"
​
2: "Content-Type"
​
3: "Date"
​
4: "Referrer-Policy"
​
5: "X-Content-Type-Options"
​
6: "X-Frame-Options"
​
7: "X-Permitted-Cross-Domain-Policies"
​
8: "X-XSS-Protection"
​
length: 9

This gave me a direction that the application is not seeing Set-Cookie header. I thought I'll be able to resolve it by adding CORS policy in play framework exposedHeaders = ["Set-Cookie"] but that didnt work. Later I looked closer at the cookie and noticed secureCookie setting

Set-Cookie: id=...Secure; HTTPOnly

This made me think that maybe my cookie settings are wrong for my environment (localhost, no HTTPS). I changed the cookie settings in Silhoutte

val config =  CookieAuthenticatorSettings(secureCookie=false)

And it worked!

Though I'll make the above code work for secureCookie and this wasn't an issue with Angular, I hope that some folks might find the approach helpful

"Set-Cookie" with a flag "HttpOnly" means you can not read the cookie from the client-side.