|
Kubernetes requires machines big enough to run all your containers. Those machines are the bins. Your containers are the packages. Fitting your containers in such that there is no criticality overlap (in AWS, that all instances of service X are spread across machines in different AZs) and that there is room for immediate scaling/emergency fault recovery (headroom on the machines running your containers) gets expensive. You're buying big and running little, and that comes with costs. Meanwhile, in AWS, you already have pre-sized blobs of RAM and compute. They're called EC2 instances. And then AWS pays the cost of the extra inventory, not you. (To forestall the usual, "overhead" of a Linux OS is like fifty megs these days, it's not something I'd worry about--most of the folks I know who have gone down the container-fleet road have bins that are consistently around 20% empty, and that does add up.) You may be the one percent of companies for whom immediate rollout, rather than 200-second rollout, is important, and for those companies a solution like Kubernetes or Mesos can make a lot of sense. Most aren't, and I think that they would be better served, in most cases, with a CloudFormation template, an autoscaling group with a cloud-init script to launch one container (if not chef-zero or whatever, that's my go-to but I'm also a devops guy by trade), and a Route 53 record. You're basically paying overhead for the privilege of `kubectl` that, personally, I don't think is really that useful in a cloud environment. (I think it makes a lot of sense on-prem, where you've already bought the hardware and the alternatives are something like vSphere or the ongoing tire fire that is OpenStack.) |