I would stress the out-of-the-box support for blue-green deployments in a system that is fully versioned, thus supports rollbacks like a champ.
Re:Kubernetes 1.18
by predakanga on Thursday March 26, 2020 @04:27AM
(#22691537)
This is news to me, do you have any links to k8s's support for blue-green deploys?
I've been holding off setting up a system like Spinnaker because I'd read it was coming (in the form of custom deployment strategies), but can't find anything current on the subject.
At the service level Kubernetes offers deployments
https://github.com/kubernetes/kubernetes/tree/master/pkg/con...
At an application level then the strategy consists of having two applications deployed and update the application's ingress after the deployment controller finishes updating the deployments.
I like the idea of kubernetes, and (some time ago) worked through a basic tutorial. My main confusion is how to set up a development environment. Are there any guides you could suggest that cover basic workflows?
Minikube is super easy to use, or k3s.
You can migrate docker deployments to K8s just by adding the parts you were missing, so when in doubt, it always makes sense to start with docker, docker-compose, and only consider K8s as an alternative to docker swarm.
In practice, I found docker to be much more brittle than kubernetes, even when kubelet uses docker underneath. K8s minimizes the amount of "features" used from docker, and unlike docker is properly designed for deployment use out of the box (and generally has cleaner architecture, so figuring out server failures tended to be easier for me with k8s than with docker daemon)
I actually spent the past 3 days attempting to migrate my DIY “docker instances managed by systemd” setup to k8s, and found getting started to be a huge pain in the ass, eventually giving up when none of the CNIs seemed to work (my 3 physical hosts could ping each other and ping all the different service addresses, but containers couldn’t ping each other’s service addresses).
That said, if anyone REALLY wants to go the k8s route, it seems like starting with vanilla docker did allow me to get 75% of the work done before I needed to touch k8s itself :)
Although I would argue that you need to know what trade offs you are making if you have the right use-case (multiple containers you need to orchestrate, preferably across multiple machines) and you are not using it or a similar tool. There are lots of best-practices and features you get out of the box, that you would have to implement yourself.
You get:
* Deployments and updates (rolling if you so wish)
* Secret management
* Configuration management
* Health Checks
* Load balancing
* Resource limits
* Logging
And so on(not even going into stateful here), but you get the picture. Whatever you don't get out of the box, you can easily add. Want Prometheus? That's an easy helm install away.
Almost every system starts out by being 'simple'. The question is, it going to _stay_ simple? If so, sure, you can docker run your container and forget about it.