Add PostgreSQL::Test::Cluster::config_data()

This is useful to grab some configuration information from a node
already set up, and I personally found two cases for it: pg_upgrade and
a test to emulate check_guc.

Author: Michael Paquier
Discussion: https://postgr.es/m/20211129030833.GJ17618@telsasoft.com
Discussion: https://postgr.es/m/YJ8xTmLQkotVLpN5@paquier.xyz

diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 265f3ae657419fddd80531bcf76ce877b147948b..41beadff9dd7fafc470e2ab3b5462dae907cb919 100644 (file)
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -327,6 +327,31 @@ sub install_path
 
 =pod
 
+=item $node->config_data($option)
+
+Return a string holding configuration data from pg_config, with $option
+being the option switch used with the pg_config command.
+
+=cut
+
+sub config_data
+{
+       my ($self, $option) = @_;
+       local %ENV = $self->_get_env();
+
+       my ($stdout, $stderr);
+       my $result =
+         IPC::Run::run [ $self->installed_command('pg_config'), $option ],
+         '>', \$stdout, '2>', \$stderr
+         or die "could not execute pg_config";
+       chomp($stdout);
+       $stdout =~ s/\r$//;
+
+       return $stdout;
+}
+
+=pod
+
 =item $node->info()
 
 Return a string containing human-readable diagnostic information (paths, etc)