Assign random integer to items in array and summa should ever be a fixed number

this is my problem

I've a variable number of items in an array

array (x, y, z, ..., n)

And i've a fixed total assigned to a variable

$min_int = 0;
$max_int = 8;
$total = 8;

I need to assign to every item in the array a random int from $min_int to $max_int and the total of the items in the array has to be always =8.

For example:

array (red, green, blue);
$min_int = 0;
$max_int = 8;
$total = 8;

the result could be

Array
(
    [0] => 3
    [1] => 5
    [2] => 0
)

OR

Array
    (
        [0] => 3
        [1] => 3
        [2] => 2
    )

I would develop in javascript.

Any suggestions please?