My Love letter to containers

The first contact with containers I had back in 2014. Some of our customers asked if we were IBM certified - whatever this means. My boss lives to 100 percent by the motto "the customer is always right", so immediately he called IBM and organized an IBM bootcamp for us...

It was a very interesting day at IBM for us. Maybe I write about the IBM experience because there were a few moments where we thought we were in a fewer dream. Back to the bootcamp...

So at that time, "cloud" was the new buzzword. IBM bought SoftLayer which was something like AWS or Azure, and integrated it as the product "Bluemix".

We ran many servers and never heard of containers before. Every piece of software on the servers was installed via package manager, or we compiled it by ourself. No abstraction at all. And yes, with every OS update or upgrade we were like:

... and therefore no one did the upgrades, or only if we knew about serious bugs... Yes, I shit you not. As a rookie, I asked the CTO if we could upgrade the Debian Lenny server. His answer was short: Sure, come in on a weekend and do it, but you should make sure that everything works. That Saturday turned into a whole weekend of work for me. Yep, I did this only once, and after that, never brought that up ever again.

We started to set up virtual machines for specific applications, which were too big of a hassle to upgrade without an abstraction. Keyword GitLab ;)

So here we are; we are sitting in a classroom at IBM, and we are learning what containers are. But... we don't get it. I know this conversation still very well. The "teacher" tried to explain to us what the cloud was:

"Imagine the cloud as a runtime for your software on the internet." I raise my hand. "So that means the cloud is a server?" "Yes, partly. Your software runs on the server, but you don't have access to it. You access only your software / container." "Okay, but it still runs on a server?" "Yes" "Okay, but why should we use containers?" "Because you could abstract your application from others." "But we already have virtual machines."

We all didn't know what the benefit was. We thought this was the next buzzword without a sense. To be fair, the "teacher" was only a sales guy from IBM and didn't have a clue either. So we should use a technique for which the teacher couldn't point any benefits to us, and we should now have to pay 5 times more for the same performance we got from a standard Hetzner server. So we finished this bootcamp and got home and never thought about containers again, but now we got a little badge on our website "IBM partner". Nice!

Years went by, and I never thought about containers again. Yes, we read about it daily on the news, and we still thought that's only a buzzword and ignored that completely, because of our bootcamp at IBM.

Fast-forward to the middle of 2016. I found an article on HN. Sadly, I don't remember which one it was, but it was an article that tried to answer every "old man yelling at cloud" answers, and it gave a brief introduction in containers.

That article explained it quite well and changed everything for me. To break it down in short, it said that containers had nearly no overhead. This means your software runs on the same kernel, and for that reason, it uses the same resources. So it's in no way or shape comparable to virtual machines because in a virtual machine you need to preserve and lock your local resources, and you emulate a lot of shit.
This simple explanation changed everything, and I got totally into containers. The next few weeks, I tinkered with Docker daily. And after four weeks, I containerized every application on my private servers. To this day, I install almost every piece of software on my servers in Docker containers, and it's such a breeze.

• No more fear of OS upgrades.
• No more fear if the installation of an app breaks other apps.
• No more long installation tutorials with many commands to execute.
• No more development setups that's different from others.

It just works, since 2016 with no issues at all.