keycloak unknown error while creating a new resource via rest api - api

Question

I am trying to create a new resource in keycloak
on keycloak UI I looged in with admin account then I created a realm called demo and a user abc in it and created a client clientA after that I have created a new resource named resourceA with scopes and policy and permissions
while on keycloak ui everything is working fine resource was created the user abc has realm roles as admin, uma_authorization and client role of the client clienA is uma_protection
when i try to create a resource via rest api i am getting {"error":"unknown_error"}
Here are the steps I am following
obtained a pat as shown here
curl -X POST \
-H "Content-Type: application/x-www-form-urlencoded" \
-d 'grant_type=client_credentials&client_id=clientA&client_secret=given client secret' \
"http://localhost:8080/auth/realms/demo/protocol/openid-connect/token"
I got the access token (pat) then I followed next step
curl -v -X POST \
http://localhost:8080/auth/realms/demo/authz/protection/resource_set \
-H 'Authorization: Bearer '$here i am adding the pat i received from the previous step \
-H 'Content-Type: application/json' \
-d '{
"resource_scopes":[
"read-public",
"post-updates",
"read-private",
"http://www.example.com/scopes/all"
],
"icon_uri":"http://www.example.com/icons/sharesocial.png",
"name":"Tweedl Social Service",
"type":"http://www.example.com/rsrcs/socialstream/140-compatible"
}'
I got {"error":"unknown_error"} as a response with status code 400 Bad request. What am I missing here ?

Answer 1

I know what it feels like :)
Reason
org.keycloak.services.error.KeycloakErrorHandler gets error text from WebApplicationException::getMessage method result.
public Response toResponse(Throwable throwable) {
//...
error.setError(getErrorCode(throwable));
//...
}
private String getErrorCode(Throwable throwable) {
if (throwable instanceof WebApplicationException && throwable.getMessage() != null) {
return throwable.getMessage();
}
return "unknown_error";
}
And if caused exception is another type of RuntimeException you will get "unknown_error"
Solution (short path):
Extend WebApplicationException and implement your own constructor and getMessage method like that:
public class CustomException extends WebApplicationException {
private final String message;
public AbstractUserException(Throwable throwable) {
// log exception if you want
this.message = throwable.getMessage();
}
#Override
public String getMessage() {
return message;
}
}
Wrap the main code of your resource in the try catch block, which always will throw your custom Exception
try {
// your code
} catch (Exception e) {
throw new CustomException(e);
}
Voila! You will get a readable error in response
P.S. If you want to go further - you can throw your exception with a complete HTTP Response object, which may contain custom HTTP status code, etc