Posts with the “Kubernetes” tag

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Have you ever wanted to move a Kubernetes volume (Persistent Volume Claim) to another storage class or back it up? We do it now and again so we created a generally useful container image that can be attached to a pair of volumes to then automatically copy (using rsync) from one to the other.

Have a look at our docker-volume-replicator repository and accompanying public Docker image.

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We recently encountered a Kubernetes cluster that had experienced catastrophic etcd failure. We had 3 nodes running etcd that had suddenly been reduced to one without quorum. Repairing the situation required action on a number of fronts.

We had no viable backups, and had to rely on the db file that was left on the remaining etcd node.

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Try using popeye, a Kubernetes Cluster Sanitizer, to help lint objects deployed to Kubernetes to detect misconfigurations, and give you some feedback on compliance with community best practices.

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Here we’re going to explore repetitive project content and one method you can employ to automate its generation.

After creating a few Ansible-based Kubernetes projects the boilerplate begins to emerge on two fronts - a number of mandatory Ansible files and the Kubernetes object definitions. What’s most frustrating is that, for the most part, Kubernetes objects are often detailed (verbose) yet irritatingly repetitive and predictable.

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In this article we’ll see how to deploy container images from a [GitLab] private registry into Kubernetes.

Public container images, in registries like [Docker Hub], can be deployed easily without needing to provide any credentials. Kubernetes Deployments (and other objects like StatefulSets) simply need the image, i.e. informaticsmatters/neo4j:3.5.20. However, images resident on a private registry will require you to deploy an ImagePullSecret that Kubernetes uses to pull the image.

[Kubernetes documentation] describes such secrets with a section explaining how they can be created from the command-line.

Here we provide a brief cheat-sheet that explains how to create a pull-secret using [GitLab] and then use that in a Deployment.

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In this brief article we’ll see how to setup a Kubernetes nginx ingress to redirect HTTP traffic from example.com to www.example.com.

Prerequisites here are a cluster with an nginx ingress controller and a route to the cluster. This relies on your domain routing example.com and www.example.com to your cluster, usually through some form of load-balancer. We’re not going to cover these aspect of the solution, just the ingress definition you need.

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In this article we’ll see how simple it is to install Kubernetes onto some Ubuntu hosts using [Pharos].

Pharos is a Certified Kubernetes with all batteries included. It is powered by the latest upstream version of Kubernetes kernel and include tools for cluster lifecycle management.