Mitigate CVE-2026-31431 (Copy-Fail) by Disabling the algif_aead Kernel Module Using Ansible
The CVE is found by Xint Code and it is well-explained here: https://copy.failHere is an Ansible playbook that follows the official interim mitigation before a patched kernel is rolled out.[...]
Understanding `sudo` Flags and Logging: A Practical Guide
The sudo command is one of the most powerful and commonly used toolson Unix-like systems. It allows a permitted user to execute commands asanother user---typically the root user. But not all sudo usage isequal: flags change its behavior, and logs record what users do forauditing and security purposes.This post explains:Common and important sudo flags\How standard sudo logs work\What sudo I/O logs (iologs) are and what they capture\Practical considerations for automation and security[...]
Fixing SSH “Match” Blocks Breaking Host Aliases: A Subtle but Important Trick
When configuring SSH, most developers know the basics— Host, HostName, IdentityFile, and so on. But once you start using Match blocks and Include statements in more complex setups (multiple keys, multiple users, multiple environments), you can easily run into a very subtle problem:[...]
Enhance Infrastructure Observability with Cost Metrics
In the world of SRE, we talk a lot about observability, such as metrics, logs, and traces. In most cases, these three pillars of observability are related to infrastructure metrics or business metrics. For example, the current CPU usage of a Kubernetes pod, the number of videos played by online users per minute, etc. Besides this, there is another important area that is being explored nowadays: FinOps.[...]
1. Check the partitions information of the target disk.sudo fdisk -l # OR sudo parted -l[...]
[OpenStack] How to Deploy a Kubernetes Cluster Using Kubeadm
This blog presents how to deploy a self-hosted Kubernetes cluster using kubeadm.Note that usually we use kubeadm to bootstrap a K8s cluster that has several nodes. It is also easy to scale up the created cluster using kubeadm later. However, if you only need to have a learning environment of K8s, it might be easier to use some tools like kind, and minikube: https://kubernetes.io/docs/tasks/tools/[...]
[OpenStack] How to Create an Internal Network
By default, there is only one network created in an OpenStack project. But for some scenarios, you might need to create several instances and organize them in an internal network. This internal network could be connected to the public Internet through a router (more discussions in this issue). This blog demonstrates how to create such an internal network in an OpenStack project. A corresponding tutorial video could be found at https://www.youtube.com/watch?v=3RmUpWA7U1Q[...]
Sometimes when we use a virtual machine on some cloud platforms such as Azure, we might face the following scenario. The hard disk is running out of space. Thus we expand the size of that hard disk from the cloud platform's dashboard. After logging in to the system again, we find that the size of the disk is successfully expanded while the partition remains the same size.[...]