etcd is a fast, reliable and fault-tolerant key-value database. It is at the heart of Kubernetes and is an integral part of its control-plane. It is quite important to have the experience to back up and restore the operability of both individual nodes and the whole entire etcd cluster.
In the previous article, we looked in detail at regenerating SSL-certificates and static-manifests for Kubernetes, as well as issues related to restoring the operability of its control-plane. This article will be fully devoted to restoring an etcd-cluster.
First and foremost I should make a reservation that we will only consider a…
Heh, I didn't found any solution suitable to me so I wrote my own.
I would say that it is most elegant solution for bare-metal deployments as it very simple. It uses PXE-booting feature for the physical servers and containerized Kubernetes control-plane.
You can prepare your own server-image with all software you need just simple using Dockerfile. Right now it is Ubuntu based but in the future it's planned to be distro agnostic.
To bootstrap new cluster you just need to pass parameters and install Helm-chart.
Please take a look at github.com/kvaps/kubefarm
Kubernetes is a great platform both for container orchestration and everything else. Recently, Kubernetes has gone far ahead in terms of functionality, security and resilience. The Kubernetes architecture allows you to easily survive various kinds of failures and always stay afloat. Today we will break the cluster, delete certificates, rejoin nodes on live, and doing all this fancy stuff without possible downtime for already running services.
Some time after writing the first article, where I cleverly use jsonnet and gitlab, I realized that pipelines are certainly good, but unnecessarily difficult and inconvenient.
In most cases, a typical task is need: “to generate YAML and put it in Kubernetes”. Actually, this is what the Argo CD does really well.
Argo CD allows you to connect a Git repository and sync its state to Kubernetes. By default several types of applications are supported: Kustomize, Helm charts, Ksonnet, raw Jsonnet or simple directories with YAML/JSON manifests.
Most users will be happy for having just this tool set, but not…
Hi, recently I faced across an interesting task to setup a storage server for backup of a large number of block devices.
Every week we back up all virtual machines in our cloud, so there is a need to be able handle thousands of backups and do it as fast and efficiently as possible.
Unfortunately, the standard RAID5, RAID6 levels are not suitable due the fact that recovery process on such large disks as ours will be painfully long and most likely never finished successfully.
Let’s consider what alternatives are:
Erasure Coding — An analogue to RAID5, RAID6, but with…
Not so far ago, I was faced with a quite unusual task of configuring routing for MetalLB. All would be nothing, since MetalLB usually does not require any additional configuration from user side, but in our case there is a fairly large cluster with a quite simple network configuration.
In this article I will show you how to configure source-based and policy-based routing for the external network on your cluster.
I will not dwell on installing and configuring MetalLB in detail, as I assume you already have some experience. Let’s understand the essence and configure the routing. …
Gitlab CI have a nice feature to generate docker-registry tokens per each job, but this feature is working only for it’s own docker registry and does not working with an external ones, eg. Harbor, Nexus, Quay and etc.
There is an opportunity to set-up external docker registry for Gitlab, it is well described in the documentation Use an external container registry with GitLab as an auth endpoint.
Proposed to configure brand new docker-registry with token based authentication. Harbor also uses docker-registry in backend, so that we could configure it, but problem is that both Gitlab and Harbor require to set…
Recently, many cool automation tools have been released both for building Docker images and for deploying to Kubernetes. In this regard, I decided to play with the Gitlab a little, study its capabilities and, of course, configure the pipeline.
The source of inspiration for this work was the site kubernetes.io, which is automatically generated from source code.
For each new pullrequest the bot generates a preview version with your changes automatically and provides a link for review.
I tried to build a similar process from scratch, but entirely built on Gitlab CI and free tools that I used to…
Let me tell you how you can safely store SSH keys on a local machine, for not having a fear that some application can steal or decrypt them.
This article will be especially useful to those who have not found an elegant solution after the paranoia in 2018 and continue storing keys in
To solve this problem, I suggest you using KeePassXC, which is one of the best password managers, it is using strong encryption algorithms, and also it have an integrated SSH agent.
This allows you to safely store all the keys directly in the password database and…
I had a need to show dashboard with monitoring information on several screens in the office. There are several old Raspberry Pi Model B+ and a hypervisor with a virtually unlimited amount of resources.
Apparently the Raspberry Pi Model B+ does not have enough power to keep the browser running constantly and draw a large amount of graphics in it, which is why the page is partially buggy and often crashes.
I found a fairly simple and elegant solution, which I want to share with you.
As you know, all Raspberries have a quite powerful video processor, which is great…