How to merge two related DataFrame in Spark?

Question

Scala

Hello colleagues!
I'm taking my first steps in the Spark Framework and can't figure out how to merge two DataFrames.
The first DataFrame stores data about user requests to the service center. This DataFrame can be called conditionally df1.

+-----------+---------------------+
| USER_NAME | REQUEST_DATE        |
+-----------+---------------------+
| Alex      | 2018-03-01 00:00:00 |
| Alex      | 2018-09-01 00:00:00 |
| Bob       | 2018-03-01 00:00:00 |
| Mark      | 2018-02-01 00:00:00 |
| Mark      | 2018-07-01 00:00:00 |
| Kate      | 2018-02-01 00:00:00 |
+-----------+---------------------+

The second DataFrame stores information about user licenses. Conventionally, this DataFrame can be called df2.

+-----------+---------------------+---------------------+------------+
| USER_NAME | START_SERVICE       | END_SERVICE         | STATUS     |
+-----------+---------------------+---------------------+------------+
| Alex      | 2018-01-01 00:00:00 | 2018-06-01 00:00:00 | Active     |
| Bob       | 2018-01-01 00:00:00 | 2018-02-01 00:00:00 | Not Active |
| Mark      | 2018-01-01 00:00:00 | 2018-05-01 23:59:59 | Active     |
| Mark      | 2018-05-01 00:00:00 | 2018-08-01 23:59:59 | VIP        |
+-----------+---------------------+---------------------+------------+

After join I want to receive such final DataFrame. How to do it? That is, at the time the user contacted the service center, what license status he had should be found out.

+-----------+---------------------+----------------+
| USER_NAME | REQUEST_DATE        | STATUS         |
+-----------+---------------------+----------------+
| Alex      | 2018-03-01 00:00:00 | Active         |
| Alex      | 2018-09-01 00:00:00 | No information |
| Bob       | 2018-03-01 00:00:00 | Not Active     |
| Mark      | 2018-02-01 00:00:00 | Active         |
| Mark      | 2018-07-01 00:00:00 | VIP            |
| Kate      | 2018-02-01 00:00:00 | No information |
+-----------+---------------------+----------------+