Context I was tempting to try out NetworkPolicy1 on Kubernetes as a secure way to protect traffic in and out Pods. Today a friend of mine who was pursuing "Certified Kubernetes Application Developer" asked me a problem related to it. He was using a small set of exercises 2 to practice Kubernetes. The problem statement … Continue reading Trying out NetworkPolicy on Kubernetes running on Docker for macOS
Category: journal
Convert checksum between Hex and Base64 using CLI
Checksums produced by SHA1, SHA2 are usually in hex format. However, there also come in base64. I just discovered a way to convert between the two. https://gist.github.com/Genzer/e220735a9cf5d6cfe2831edd3c89fa7a Gist
Download File and Verify Checksum in Bash
I had a need to download a gzip tarball file (.tgz), verify its checksum and extract one particular file in it. All in one go using Bash. By using Bash's process substitution and tee, such a task could be achieved in a one-liner. I had this need when I built a Docker image for Retype, … Continue reading Download File and Verify Checksum in Bash
MongoDB failed to lock file on OpenShift using NFS file system
Summary This page documented the investigation of an issue: MongoDB Pod failed to lock mongod.lock on OpenShift/OKDv4. The problem was because NFSv3 was used to mount between OKDv4 Worker Nodes to the NFS server. MongoDB used internally flock/fcntl to lock the mongod.lock file descriptor. In a network file system like NFSv3, locking support was required … Continue reading MongoDB failed to lock file on OpenShift using NFS file system
The Collector’s Fallacy – Zettelkasten Method
On researching taking notes, speciffically the Zekkelkasten method, I learned The Collector's Fallacy. In its essenses: Saving links, copying or just reading a material does not mean that you have consumed the knowledge. You may have increased the knowlege for a short time, but it will fade away very soon after that. By taking notes, … Continue reading The Collector’s Fallacy – Zettelkasten Method
Grokking Hard 