インスタンスのNameタグから、そのインスタンスに付いてるsecurity groupの名前を得

sgs_by_name.pl

    my $ec2 = Net::Amazon::EC2->new(
        AWSAccessKeyId  => $config->{AWSAccessKeyId},
        SecretAccessKey => $config->{SecretAccessKey},
        region          => $config->{region},
    ) or die;

    my ($instance) =
        grep {
            grep { $_->value eq $name }
            grep { $_->key eq 'Name'  }
            @{ $_->tag_set || [] };
        }
        map { $_->instances_set }
        @{ $ec2->describe_instances };

    return () unless $instance;

    my $group_set = $ec2->describe_instances(
      InstanceId => [ $instance->instance_id ]
    )->[0]->group_set;

    my @sgs=
        map { $_->group_name }
        @{ $group_set };
        
    return @sgs