Getting error 502 when using REST API to retrieves list of all applications - ibm-mobilefirst

Question

GET /imfpush/v1/apps HTTP/1.1
Host: mobilefoundation-3b-mf-server.mybluemix.net
Authorization: Bearer eyJhbGciOiJSUzI1NiIsImp....
Content-Type: application/json
another type of invocation
curl -X GET -H "Authorization: Bearer eyJhbGciOiJSUzI1N...." "https://mobilefoundation-3b-mf-server.mybluemix.net/imfpush/v1/apps"
Error 502: Failed to make token request, reason: Unsuccessful request to Authorization Server, server responded with status code: 400 and body : {"errorCode":"invalid_client"}, check the Authorization URL: http://localhost:8080/mfp/api/az/v1/token

Answer 1

TL;DR: right now looks like there is a bug in the /imfpush/v1/apps endpoint where it does not filter the applications by the vendor (APNS, GCM, WNS), so you can only get a list of all applications instead...
Note however that it all depends on your end goal. You can accomplish this by code or by using tools such as curl or Postman, Swagger etc... it all depends on what you want to achieve.
Here are 3 ways:
In the local development server - not available in Mobile Foundation service on Bluemix, you can use this URL to see the REST endpoints exposed in Swagger. You can then view push-enabled applications with this one: http://localhost:9080/doc/?url=/imfpush/v1/swagger.json#!/Applications/getAllApplications
First, in MobileFirst Operations Console > Runtime Settings > Confidential clients:
Add (just an example, choose your own) a new user client (id: user, secret: user)
Add the apps.read and push.application.* scopes
Be sure to click on the knob and add the apps.read and push.applications.* scopes.
You will also be asked to authorize. Use the username and password for the user confidential client that you previously created.
Using the /imfpush service, as described below.
Using the mfpadmin service, as described below.
In my examples I will use Postman.
In MobileFirst Operations Console > Runtime Settings > Confidential clients:
Added (just an example, choose your own) a new user client (id: user, secret: user)
Added the apps.read and push.application.* scopes
Obtained an access token by making a POST request to http://localhost:9080/mfp/api/az/v1/token with:
Authorization tab:
Type: Basic Auth
user: user
password: user
Body tab:
x-www—form-urlencoded
grant_code: client_credentials
scope: apps.read push.application.*
Obtained the list of applications by making a GET request to http://localhost:9080/imfpush/v1/apps with:
Headers tab:
Authorization: Bearer the-access-token-from-step-2
To filter the list by platform, the URL should change to the following, like the example in the API documentation: http://localhost:9080/imfpush/v1/apps/?expand=true&filter=platform==A&offset=0&size=10 But since this does not work right now... use: http://localhost:9080/imfpush/v1/apps/
Of course, you need to change localhost to your server's host.
To only obtain a list of all applications, it'd be faster to use the mfpadmin service applications endpoint. Using Postman:
Created a new GET request to http://localhost:9080/mfpadmin/management-apis/2.0/runtimes/mfp/applications
You can change the domain to yours.
In the Authorization tab, I have set the following:
Type: Basic Auth
Username and Password: your username and password (to the console)
In return I have received a list of registered applications.