FPM pools can't be specified in code

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 6.12
• Ruby: 2.5.1
• Distribution: ubuntu 18.04
• Module version: 7.1.0

How to reproduce (e.g Puppet code you use)

	class { 'php':
		fpm => true,
		fpm_pools => {
			'www' => {
				'listen' => '0.0.0.0:9000',
			},
		},
	}

What are you seeing

FPM is listening on localhost only (code above specifies all interfaces)

root@29b721b3c7a6:/# grep 'listen =' /etc/php/7.2/fpm/pool.d/www.conf 
listen = 127.0.0.1:9000

What behaviour did you expect instead

FPM is listening on all interfaces

root@29b721b3c7a6:/# grep 'listen =' /etc/php/7.2/fpm/pool.d/www.conf 
listen = 0.0.0.0:9000

Output log

Any additional information you'd like to impart

I believe this is caused by #550. Hiera settings override the parameter default which is set to take the values from class php.

I tried to provide a test showing the expected behavior, but I couldn't figure out how and the test suite is broken anyway.

A possible solution might be to have the hiera defaults for php::fpm_pools instaed of php::fpm::pools, but that might well be a breaking change.

Trace how the php::fpm_pools class parameter and the php::fpm::pools Hiera defaults are merged, using the reported Puppet example as the starting point. Check the existing test suite, which the report says is broken, and consider the compatibility impact of changing the Hiera defaults. Done means the generated pool configuration uses 0.0.0.0:9000 when specified in code.