https://barun.cc/ Recent content on Barun Acharya Hugo -- gohugo.io en Sat, 28 Feb 2026 00:00:00 +0000 https://barun.cc/posts/free-vs-oss/ Wed, 22 Jul 2020 00:00:00 +0000 https://barun.cc/posts/free-vs-oss/ Softwares are a integral part of our lifestyle right now. Some of them are proprietary and some of them are not. The one’s which are not proprietary are generally associated with FOSS i.e. Free and Open Source Software. Let’s dig a bit deeper into the non proprietary world. What is FOSS? FOSS i.e Free and Open Source Software, is any piece of software that is freely licenced to use,study,copy and modify and the source-code is openly shared so that people are encouraged to voluntarily contribute to it. https://barun.cc/posts/ebpf-clone-map-thread-pool/ Sat, 28 Feb 2026 00:00:00 +0000 https://barun.cc/posts/ebpf-clone-map-thread-pool/ A recurring challenge in eBPF-based automatic instrumentation is this: the thread that does the interesting work is not the thread that has the context. Your tracer registers a span under TID 1001. The work executes on TID 1002. The two events are causally related — but from the kernel’s perspective, they’re just two different threads. The clone map pattern is a simple, verifier-friendly way to bridge that gap by tracking thread ancestry directly in BPF. https://barun.cc/posts/ebpf-ktime-monotonic-wallclock/ Sat, 28 Feb 2026 00:00:00 +0000 https://barun.cc/posts/ebpf-ktime-monotonic-wallclock/ When you write your first eBPF tool — whether it’s capturing logs, emitting performance events, generating security alerts, or building an observability pipeline — timestamping events feels trivial. Call bpf_ktime_get_ns(), store the result in your event struct, ship it out the ring buffer. Done. Then you try to correlate those events with the outside world and discover the timestamps are nonsense — off by days, weeks, or the entire uptime of the machine. https://barun.cc/posts/bpf-lsm-armor/ Sun, 10 Jul 2022 00:00:00 +0000 https://barun.cc/posts/bpf-lsm-armor/ A few months back I presented at Cloud Native eBPF Day Europe 2022 about Armoring Cloud Native Workloads with BPF LSM and planted a thought about building a holistic tool for runtime security enforcement leveraging BPF LSM. I have spent the past few weeks collaborating with the rest of the team at KubeArmor to realize that thought. This blog post will explore the why’s and how’s of implementing security enforcement as part of KubeArmor leveraging BPF LSM superpowers at its core. https://barun.cc/posts/cover-run/ Sat, 09 Oct 2021 00:00:00 +0000 https://barun.cc/posts/cover-run/ I am safe and sound, not looking for cover :P But the team at KubeArmor was looking for coverage statistics for their end to end tests. I will go about how we achieved that in this post. Pretty anti dramatic considering the title uhh, but I will try to keep this post interesting :D Before I start, let’s discuss about what is code coverage and why are we running for it https://barun.cc/posts/gsoc21/ Tue, 31 Aug 2021 00:00:00 +0000 https://barun.cc/posts/gsoc21/ Had an awesome summer working with PublicLab under Google Summer of Code 😊🚀 Here’s my post about what I did and how was my experience 😬. Hope you appreciate the memes I put in it 😜🤣 Link to project on GSoC Project List Looking forward to continue being part of and working with the awesome community 😊❣️ https://barun.cc/posts/leaving-whatsapp/ Mon, 11 Jan 2021 00:00:00 +0000 https://barun.cc/posts/leaving-whatsapp/ The reasons seems to be obvious, the new privacy policy. Am I also part of the herd? Is it because everyone seems to be moving to it? Na I have been using signal for quite a time now but I mostly used it for saving notes to self, since nobody else seemed to use it. Even if you are trying it out just because Elon Musk tweeted “Use Signal” it’s fine, Signal is worth it. https://barun.cc/posts/file-descriptors-and-resource-usage-limits/ Sun, 01 Nov 2020 00:00:00 +0000 https://barun.cc/posts/file-descriptors-and-resource-usage-limits/ Backstory I was working on a project in go where I had to open and play around with too many files at once ( around 50 thousand ). The program ran fine when I was working with one file at a time. But when I tried to make it concurrent, I had an error saying Too many open files. Now that’s weird cause my hardware wasn’t the bottleneck, I had enough free ram, my CPU wasn’t maxed out and I had plenty of empty storage. https://barun.cc/posts/basic-shell-commands-and-how-do-they-execute/ Fri, 24 Jul 2020 00:00:00 +0000 https://barun.cc/posts/basic-shell-commands-and-how-do-they-execute/ Shell A shell is a command line interface for a UNIX-like operating system. A UNIX system offers a variety of shell types like sh or Bourne Shell bash or Bourne Again shell : It is the standard GNU shell used commonly by Linux users. csh or C Shell ksh or Korn Shell and many more . . You can see what shell are available in your system by running cat /etc/shell https://barun.cc/about/ Mon, 01 Jan 0001 00:00:00 +0000 https://barun.cc/about/ Hey there, I’m Barun 👋 I like hacking on low-level stuff and fiddling around with developer tooling. I currently work as a Software Engineer at Odigos, simplifying OpenTelemetry Auto Instrumentation, and I’m also a maintainer for KubeArmor, a CNCF Sandbox project. I love speaking at conferences. I’m a proud CNCF Ambassador and actively mentor through programs like Google Summer of Code and LFX Mentorship. I’ve been involved with Public Lab Code Community under Google Summer of Code ‘21 https://barun.cc/contact/ Mon, 01 Jan 0001 00:00:00 +0000 https://barun.cc/contact/ Contact Me 🤙 If you think I can help with anything, want me to join your project team or just want to say hi, you can reach out to me at: Email : daemon1024 [at] pm [dot] me Twitter : @daemon1024 Telegram : @daemon1024 Matrix : @daemon1024:matrix.org I welcome all friendly communication!! https://barun.cc/talks/ Mon, 01 Jan 0001 00:00:00 +0000 https://barun.cc/talks/ My Talks Talk Event/Type Date Links IngressNightmare? Virtual Patching to mitigate CVE-2025-1974 📢 KubeCon + CloudNativeCon London 2025 April 2025 sched Patch It Up: Real-Time Vulnerability Management with Kyverno and KubeArmor 📢 SOSS Community Day 2024 2024 December 2024 video Building Security Tooling: Trials and Triumphs 📹🎙️ Live Stream November 2024 video Beekeeping Linux: Evolution of Kernel Technologies For Instrumentation 📢 IndiaFOSS 2024 September 2024 video Preventing Bank Heists and AI Takeover in Kubernetes 📢 KCD Hyderabad June 2024 slides Minimalism: Key to Kubernetes Security 📢 Kubernetes Essentials, CNCG New Delhi April 2024 video Kueue-ing Up Security for Multi-Tenant Cloud Infra at Scale 📢 KCD Pune April 2024 slides Securing Connections: Defending Telco Workloads in the Cloud Era 📢 KubeCon + CloudNativeCon Paris, 📢 OSS Summit North America March 2024 video Securing the Secrets Manager with KubeArmor 📹 Cloud Native Live January 2024 video You Choose!