Comment by mbreese
4 months ago
I think there were multiple reasons why containers started to gain traction. If you ask 3 people why they started using containers, you're likely to get 4 answers.
For me, it was avoiding dependencies and making it easier to deploy programs (not services) to different servers w/o needing to install dependencies.
I seem to remember a meetup in SF around 2013 where Docker (was it still dotCloud back then?) was describing a primary use-case was easier deployment of services.
I'm sure for someone else, it was deployment/coordination of related services.
The big selling points for me were what you said about simplifying deployments, but also the fact that a container uses significantly less resource overhead than a full blown virtual machine. Containers really only work if your code works in user space and doesn't need anything super low level (eg TCP network stack), but as long as you stay in user space it's amazing.
The main initial drive for me was that it let me separately run many things without a) trying to manage separate dependency sets, and b) Sharing RAM - Without having to physically allocate large amounts of memory to virtual machines; on an 8GB machine at a couple per VM that doesn’t let you get far.
"making it easier to deploy" is a rather... clinical description for fixing the "but it works on my machine!" issue. We could go into detail on how it solved that, but imo it comes down to that.
There's a classic joke where it turns out the solution to "it works on my machine" was to ship my machine
my view of docker, as a who thought it was a shallow wrapper on linux namespaces, is that it was a good fit for the average IT shop to solve the deployment friction
no more handmade scripts(or worse fully manual operations) stupid simple dockerfile scripts.. any employee would be able to understand and groups can organize around it
docker-compose tying services into their own subnet was really a cool thing though
Still not the case, today anyone would understand them. At least in this part of the country where I live