I don’t know how and why, but even though for the last couple of years I was spending at least few hours a week doing something with Google Cloud Platform, I never managed to notice that they have their own tool for automating infrastructure creation. You know, creating VMs, networks, storage, accounts and other resources. But it’s there, right in the main menu.
The tool is called Deployment Manager and it can build and provision virtually everything that Google Cloud Platform can provide. All in one command. As any other tool from Google it has slightly mind bending learning curve and not always up to date documentation, but it works and gets the job done. Most of the time I was automating everything starting from the host and up, using Vagrant, Ansible, docker-compose or kubectl. But automating everything from the host and down – actual infrastructure – that’s going to be interesting. Continue reading “Automating GCP Infrastructure with Deployment Manager”
I suddenly realized that I haven’t blogged about Kubernetes for quite a while. But there’s so much happening in that area! For instance, even though creating Kubernetes objects from YAML configuration was the true way, it never felt that much convenient. So here’s the solution – use helm, the package manager for Kubernetes. Continue reading “Quick intro to helm – a package manager for Kubernetes”
It feels like last months I focused way too much on debugging and .NET Core and stopped paying attention to topic I enjoyed to blog about over the last year – DevOps and distributed applications. That doesn’t feel right and in order to fix that I’ll play with something new today. For instance, with etcd.
During my romance with distributed apps, etcd always was somewhere near. It came up as alternative to Consul when I was experimenting with service discovery and configuration management. At some point etcd also comes up as a storage where Kubernetes stores its cluster data. Etcd is everywhere! So I think it worth understanding what that is and how it looks like.
Continue reading “Quick intro to etcd”
So far all examples I made for Docker in Swarm Mode or Kubernetes blog posts were built around some sort of a service: web server, message queue, message bus. After all, “service” is a main concept in Swarm Mode, and even the whole micro-service application thing has, well, a “service” in it. But what about one-off jobs: maintenance tasks, scheduled events, or anything else, that we need to run just sometimes, not as a service?
Continue reading “One-off Kubernetes jobs”
Much to my surprise, starting from the last week Kubernetes became the part of my job description. It’s no longer something just interesting to try, I actually have to understand it now. And as you probably could tell from my older k8s post, I’m not quite there. The post sort of builds a logical example (containerized web server) but something just doesn’t click.
I was trying to understand what’s missing, and it seems like the problem is in the tooling. You see, there’re two and a half ways to run something in Kubernetes. One is through ad-hoc commands, like
kubectl run or
kubectl expose. They are simple, but they also skip few important concepts happening in the background, so the whole picture stays unclear. Continue reading “Dissecting Kubernetes example”
Seeing how easy it was to provision one VM with Ansible, I can’t stop thinking: would it be as easy to deal with the whole cluster? After all, the original example I was trying to move to Ansible had three VMs: one Consul server and two worker machines. The server is ready, so adding two more machines sounds like an interesting exercise to do. So… let’s begin?
Continue reading “Provisioning cluster of VMs with Ansible”
I’m still looking for ways to automate hosts configuration. So far I’ve been using Vagrant + bash/PowerShell for configuring Linux or Windows hosts, but somehow I managed to miss the tool designed specifically for tasks like this – Ansible. It’s been around for last five years or so and became almost a synonym to “automatic configuration”. Today I’ll finally give it a try and see what difference it makes to use it comparing to provisioning with good old Bash.
Continue reading “Provisioning Vagrant VM with Ansible”
Kubernetes (or K8s) is another tool for orchestrating containerized apps in a cluster. It’s job is to find the right place for a container, fulfill its desired state (e.g. “running, 5 replicas”), provide a network, internal IP, possibly, access from outside, apply updates, etc. Originally developed by Google, now Kubernetes is open source. Continue reading “What exactly is Kubernetes”
Somehow I missed the news that starting from version 1.12 Docker containers support health checks. Such checks don’t just test if container itself is running, but rather is it doing the job right. For instance, it can ping containerized web server to see if it responds to incoming requests, or measure memory consumption and see if it’s reasonable. As Docker health check is a shell command, it can test virtually anything.
When the test fails few times in a row, problematic container will get into “unhealthy” state, which makes no difference in standalone mode (except for triggered
health_status event), but causes container to restart in Swarm mode. Continue reading “Docker health checks”