Vintage Greg Ferro

declarativeprogrammingGreg Ferro, Philosopher King of networking and prolific tech blogger/personality, had me in stitches during the latest Coffee Break episode on the Packet Pushers podcast.

Coffee Breaks are relatively short podcasts focused on networking vendor & industry news, moves and initiatives. Ferro usually hosts these episodes and chats about the state of the industry with two other rotating experts in the “time it takes have a coffee break.”

Some Coffee Breaks are great, some I skip, and then, some, are Vintage Greg Ferro, encapsulated IT wisdom with some .co.uk attitude.

Like April 25th’s, in which discussion centered around transitioning to public cloud services, Cisco’s new OpFlex platform, and other news.

During the public cloud services discussion, the conversation turned toward on-prem expertise in firewalls, which, somehow, touched Ferro’s IT Infrastructure Library (ITIL) nerve.

ITIL, if you’re not familiar with it, is sort of a set of standards & processes for IT organizations, or, as Ferro sees it:

ITIL is an emotional poison that sucks the inspiration and joy from technology and reduces us to grey people who can evaluate their lives in terms of “didn’t fail”. I have spent two decades of my professional living a grey zone of never winning and never failing.

Death to bloody ITIL. I want to win.

Classic.

Anyway on the podcast, Ferro got animated discussing a theoretical on-prem firewall guy operating under an ITIL framework:

“Oh give me a break. It’s all because of ITIL. Everybody’s in ITIL. So when you say you’re going to change your firewall, these people have a change management problem, a self change management problem, because ITIL prevents them from being clever enough. You’re not allowed to be a compute guy & a firewall guy [in an ITIL framework]. When you move to the public cloud, you throw away all those skills because you don’t need them.

Ferro’s point (I think), was that ITIL serves as a kind of retardant for IT organizations looking to move parts of their infrastructure to the public cloud, but not in just the obvious ways you might think (ie it’d be an arduous process to redo the Change Management Database & Configuration Items involved in putting some of your stack in the cloud!)

It seems Ferro is saying that specialized knowledge (ie the firewall guy & his bespoke firewall config) are threatened by the ease of deploying public cloud infrastructure, and to get to the cloud, some organizations will have to break through ITIL orthodoxy as it tends to elevate and protect complexity.

Good stuff.

But that wasn’t all. Ferro also helped me understand the real difference between declarative & imperative programming. Wheras before I just nodded my head and thought, “Hell yeah, Desired State Configuration & Declarative Programming. That’s where I want to be,” now I actually comprehend it.

It’s all about sausage rolls, you see:

Let’s say you want a sausage roll. And it’s a long way to the shop for a sausage roll. If you’re going to send a six year old down to the shop to get you a sausage roll, you’re going to say, Right. Here is $2, here’s the way to the shop. You go down the street, turn right, then left. You go into the shop you ask the man for a sausage roll. Then you carry the sausage roll home very carefully because you don’t want the sausage roll to get cold.

That’s imperative programming. Precise instructions for every step of the process. And you get a nice sausage roll at the end.

Declarative programming (or promise theory as Ferro called it), is more like:

You have a teenager of 13 or 14, old enough to know how to walk to the shop, but not intelligent enough to fetch a sausage roll without some instructions. Here’s $10, go and fetch me a sausage roll. The teenager can go to the shop, fetch you a sausage roll and return with change.

See the distinction? The teenager gets some loose instructions & rules within which to operate, yet you still get a sausage roll at the end.

Jeffrey Snover, Microsoft Senior Technical Fellow (or maybe he’s higher in the Knights of Columbus-like Microsoft order), likened declarative programming to Captain Picard simply saying, ‘Make it so!.” I was happy with that framework but I think sausage rolls & children work better.

By the way, for Americans, a Sausage Roll looks like the image above and appears to be what I would think of as a Pig in a Blanket, with my midwestern & west coast American roots. How awesome is it that you can buy Pigs in a Blanket in UK shops? 

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