Nubis Novem

Here is why should you want to know about so called “Fizz Buzz”: it is mystifying!.. No, not really, at least not if you know how to program. Simple put that is one of most common requests to write a sample code while interviewing for a programming job. As quoted on c2.com the “Fizz Buzz” request might be formulated as following:

“Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.”

As we are getting more and more acquainted with a valuable flow of free financial information provided generously by a company called Alpha Vantage, we will now come up with a Perl script that would facilitate data extraction from their feed. The abovementioned service is free, but you have to register to obtain your individual API key. For obvious reasons we will use a demo API key in our Perl code examples here. We recommend you to get your own.

When you write a Perl application with Mojolicious framework, you put tests into the t directory. Then it is very easy to run them because Mojolicious supports tests “out of the box” with test command that should run all tests one by one:

There were times when we were looking for simple yet unorthodox solutions; and this case was one of them. Imagine, if there was a Windows 2012 server with its standard VPN service (RAS, or, Remote Access, actually), configured and operational. The only problem was that static IP of the server (as seen by a connected user) was not up at all times. For instance, assume DHCP IP range for VPN clients was 172.0.2.1 – 172.0.2.199. That makes first address of the range, 172.0.2.1 the server’s address that is accessible by VPN clients (inside VPN tunnel). When server just started that IP would be down – not even pingable, let alone not routable. The IP address becomes live as soon as first VPN client is connected from outside to the RAS service. That presented a challenge for application jobs configured to run in both modes: locally on the server and from remote locations connected to the server. We would configure 172.0.2.1 as a universal connection point for all the applications and grant proper server firewall exclusions, though… they would not be able to connect if no external users connected to the VPN service yet.

A detailed how-to recipe of proper configuration of Asterisk for use with RingCentral provider with configuration file samples.

The Archive-Zip Perl module introduced as early as January 2001, then supported by several maintainers with regular updates. Most of the time Archive-Zip is alright, but there are limitations. 2016 is about to be over and the Archive-Zip still does not know how to handle newer “64bit” header ZIP format. Not only it cannot read them 64bit ZIPs; alas, it would not create those, also. With older “32bit” header ZIP archives compressing larger amount of data files presents a bigger challenge than it should. Yes, you might use a different compression format or technique. But what if we must stick with the good old ZIP file as our standard? Here is a recipe on how to handle that.

Just a quick note as we have had a few reports lately that Shrewsoft VPN client package for Mac OS X (El Capitan release) was missing in main homebrew repository. That caused troubles for folks trying to use our recipe on that subject from last year.

Just some random thoughts on a napkin. Please do not shoot the messenger, but Perl would gain a lot in readability if it had reduced even more some of its generic constructs with better use of unambiguous context. For instance, who is in favor of a separate context type for hash arrays (associative arrays usually defined as %hasharrayname), please raise your hands.

Another showcase with Palo Alto PA-3020 firewall hardware device by Palo Alto Networks running PAN OS 6.0 (PA-3000 series). This time we would like to discuss a use of multiple IP addresses on the external interface. Say, you are running into a situation where more than one HTTPS web services should be offered to the public, but they are based on separate hardware resources internally. The simple solution would be to use another IP address for incoming connection on TCP port 443 and create another NAT policy rule for that additional address.

It is typical for a Windows server to have a auto-generated self-signed certificate for its Remote Desktop service. Not a good practice. Especially when RDP service is exposed on the internet (via TCP port 3389 that would be open in firewall). Here are a few simple steps to install a valid SSL certificate to be used with RDP to protect the host identity and encrypt your remote desktop sessions properly.