Loopback 4 authorization provider not working

Question

I have a custom authentication strategy in my loopback 4 application. Now for authorization, I need to access the token which contains user details. I have created a very basic authorization provider but the problem is this provider is not getting called. Even the console.logs in the authorization provider are not getting displayed. I have also binded this provider in application.ts.

Here is my code.

Thank you in advance

authorize.ts

import { AuthorizationContext, AuthorizationDecision, AuthorizationMetadata, Authorizer } from '@loopback/authorization';
import { inject, Provider } from '@loopback/core';
import { RestBindings, Request } from '@loopback/rest';

export class MyAuthorizationProvider implements Provider<Authorizer> {
  constructor(@inject(RestBindings.Http.REQUEST) private req: Request) { }

  /**
   * @returns authenticateFn
   */
  value(): Authorizer {
    return this.authorize.bind(this);
  }

  async authorize(
    authorizationCtx: AuthorizationContext,
    metadata: AuthorizationMetadata,
  ) {
    console.log('authorize') // not getting displyed
    console.log(this.req.headers.authorization) // not getting displyed
    if (true) {
      console.log(true) //not getting displyed
    }
    else {
      console.log(false) //not getting displyed
    }

    return AuthorizationDecision.ALLOW;

  }
}

controller

@authenticate('firebase')
  @authorize({ allowedRoles: ['retailers'] })

  @get('url')

application.ts

let app = new Application();

    const authOptions: AuthorizationOptions = {
      precedence: AuthorizationDecision.DENY,
      defaultDecision: AuthorizationDecision.DENY,
    };

    const binding = app.component(AuthorizationComponent);
    app.configure(binding.key).to(authOptions);

    app
      .bind('authorizationProviders.my-authorizer-provider')
      .toProvider(MyAuthorizationProvider)
      .tag(AuthorizationTags.AUTHORIZER);

Answer 1

For anyone facing the same issue, there is an issue in documentation. In application.ts replace your code with the following one. In the docs, it is advising to create a new app and that is the reason it is not working. Please see https://github.com/strongloop/loopback-next/issues/6580

// ------ ADD SNIPPET AT THE BOTTOM ---------
// Mount authentication system
this.component(AuthenticationComponent);
// Mount jwt component
this.component(JWTAuthenticationComponent);
// Bind datasource
this.dataSource(DbDataSource, UserServiceBindings.DATASOURCE_NAME);

// ---------- MAKE SURE THE FOLLOWING PARTS ARE CORRECT
// bind set authorization options
const authoptions: AuthorizationOptions = {
  precedence: AuthorizationDecision.DENY,
  defaultDecision: AuthorizationDecision.DENY,
};

// mount authorization component
const binding = this.component(AuthorizationComponent);
// configure authorization component
this.configure(binding.key).to(authoptions);

// bind the authorizer provider
this
  .bind('authorizationProviders.my-authorizer-provider')
  .toProvider(MyAuthorizationProvider)
  .tag(AuthorizationTags.AUTHORIZER);

// ------------- END OF SNIPPET -------------

//new
this.bind(UserServiceBindings.USER_SERVICE).toClass(MyUserService);