don't set data_directory in the config by default

[evgeni]

Describe the Bug

Today, we always set data_directory = … in postgresql.conf via

puppetlabs-postgresql/manifests/server/instance/config.pp

Lines 222 to 225 in 411e7bc

	postgresql::server::config_entry { "data_directory_for_instance_${name}":
	key => 'data_directory',
	value => $datadir,
	}

However we also set it in the systemd override:

puppetlabs-postgresql/manifests/server/instance/systemd.pp

Lines 29 to 34 in 411e7bc

	content => epp('postgresql/systemd-override.conf.epp', {
	port => $port,
	datadir => $datadir,
	extra_systemd_config => $extra_systemd_config,
	}
	),

puppetlabs-postgresql/templates/systemd-override.conf.epp

Line 11 in 411e7bc

Environment=PGDATA=<%= $datadir %>

And pass it when calling initdb:

puppetlabs-postgresql/manifests/server/instance/initdb.pp

Line 153 in 411e7bc

$datadir_parameter = "--pgdata '${datadir}'"

The problem is that setting data_directory in the config actually overrides the -D parameter on the CLI and the PGDATA environment variable, as can be seen in e.g. https://bugzilla.redhat.com/show_bug.cgi?id=1935301 thus possibly breaking future actions against this DB (see the link for an example, also https://www.postgresql.org/message-id/3566642.1618422939%40sss.pgh.pa.us).

Expected Behavior

data_directory not set in postgresql.conf when systemd is used and thus the environment variable is present

Steps to Reproduce

install a postgresql setup :)

Environment

• Version 10.0.3
• Platform CentOS Stream 8

Additional Context

This is the exact opposite of #510 🤷‍♀️