use LWP;
use LWP::UserAgent;
use HTTP::Request;
use JSON;

my $host 		= 	'https://jira.hostname:PORT/jira/rest';
my $loginurl 	        = 	'/auth/1/session';
my %credentials         = 	("username"=>"myuser", "password"=>"mypass");
my $json 		= 	encode_json \%credentials;
my $request 		= 	HTTP::Request->new('POST', $host.=$loginurl);
$request		->	header('Content-Type'=>'application/json');
$request		->	content($json);

my $browser 	        =	LWP::UserAgent->new;
$browser  		->	agent('Mozilla/5.0');
$browser		->	protocols_allowed(['https']);
my $response 	        = 	$browser->request($request);
     
if($response->is_success){
print $response->decoded_content; 
}
else {
    die $response->status_line;
};