Author Archives: Grischa Ekart

About Grischa Ekart

I am a DevOps consultant writing about Docker, Kubernetes, AWS, IT, strategy, management, mobility, business cases, apps, consumer electronics and MBA education.

Changing Encryption of PersistentVolumes in Kubernetes

Docker containers are treated as ephemeral, specifically when they are managed in a Kubernetes cluster. Starting and restarting in the cluster is done automatically and works as a breeze. Things get more complicated as soon as you decide to keep … Continue reading

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List Kubernetes Master Nodes

You can use the command below to show all nodes that are acting as master on your cluster. This is particularly useful when dealing with kops and some versions of canal networking that (accidentally) manipulate the status of the nodes. … Continue reading

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Using kops and AWS Bastion Hosts Correctly

You have correctly provisioned your AWS infrastructure using AWS Bastion Quickstart or with kops and want to connect to your private instances using the bastion hosts. First some principles: Terminate your bastion host after using it (set autoscaling to 0). … Continue reading

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Kubernetes: How to Find Out if ABAC or RBAC is Active

If you want to find out what authorization mode your cluster is running use:

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Kubernetes: kubectl run with ImagePullSecrets

If just want to quickly start a pod then you can use the following one-liner: This will limit you to public repos. There is no equivalent to using imagePullSecrets in your yaml files, so this won’t work: However you can … Continue reading

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Terminal: Copying Long Text Lines Without Newline Breaks

If you copy long wrapped lines of shell code in Mac Terminal.app you want the pasted line to be broken down into multiple lines exactly where they were in the original script. When you are using more, less or any … Continue reading

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Kubernetes: Using kubectl with 100s of Clusters

If you are working with many clusters, you need to configure multiple kubectl configs. You can do this using kubectl –kubeconfig= or by merging your config files. If however you want to keep access to your config files separate, you … Continue reading

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Using your Synology Diskstation as a SOHO git Server

Yes, you should use GitHub for your public and private repos (IMHO), but if you just need a small office solution with a few machines and / or users and already have a Diskstation (RAID config and backup recommended) why … Continue reading

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Kubernetes & Kops: Make Your Own Encrypted Debian AMI

Kops is the most popular solution to install Kubernetes on AWS in a highly-available way. Debian is the preferred Linux distro for kops, which is somewhat annoying if you see that CoreOS is the preferred container Linux. Moreover, the Debian … Continue reading

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Kubernetes: Make Pods Run on Your Master Nodes

Some pods you might want to run on your master nodes, too. This may be because they are exporting master node metrics or even to save resources: say you want many instances of a specific pod. In that case (and … Continue reading

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