addressing some code review comments

Signed-off-by: Brian Fletcher <brian@roadie.io>

plugins/auth-node/src/DefaultIdentityClient.ts

@@ -27,7 +27,6 @@ import { GetKeyFunction } from 'jose/dist/types/types';
 
 import { BackstageIdentityResponse } from './types';
 import { getBearerTokenFromAuthorizationHeader, IdentityApi } from '.';
-import { Request } from 'express';
 
 const CLOCK_MARGIN_S = 10;
 
@@ -78,7 +77,7 @@ export class DefaultIdentityClient implements IdentityApi {
   async getIdentity(req: Request) {
     try {
       return await this.authenticate(
-        getBearerTokenFromAuthorizationHeader(req.headers.authorization),
+        getBearerTokenFromAuthorizationHeader(req.headers.get('authorization')),
       );
     } catch (e) {
       return undefined;

plugins/auth-node/src/IdentityApi.ts

@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import { Request } from 'express';
 import { BackstageIdentityResponse } from './types';
 
 /**
@@ -29,7 +28,5 @@ export interface IdentityApi {
    * Returns a BackstageIdentity (user) matching the token.
    * The method throws an error if verification fails.
    */
-  getIdentity(
-    req: Request<any>,
-  ): Promise<BackstageIdentityResponse | undefined>;
+  getIdentity(req: Request): Promise<BackstageIdentityResponse | undefined>;
 }