Name: A Debugging Journey from Coredns to Coreutils - Akhil Mohan & Humble Devassy Chirammal, VMware by Broadcom
Start: 2024-12-12T11:30:00+0530
End: 2024-12-12T12:05:00+0530

In-person
11-12 December
Learn More and Register to Attend

The Sched app allows you to build your schedule but is not a substitute for your event registration. You must be registered for KubeCon + CloudNativeCon India 2024 to participate in the sessions. If you have not registered but would like to join us, please go to the event registration page to purchase a registration.

Please note: This schedule is automatically displayed in India Standard Time (UTC+5:30). To see the schedule in your preferred timezone, please select from the drop-down menu to the right, above "Filter by Date." The schedule is subject to change and session seating is available on a first-come, first-served basis.

Thursday December 12, 2024 11:30am - 12:05pm IST

201

It all started when CoreDNS pods entered a crash loop backoff state soon after the cluster was deployed. The only change was an unprivileged execution desired in the latest coreDNS image. The issue occurred only in worker nodes, not in control plane nodes, and refreshing the image by deleting and pulling it again resolved the issue. It happened in one OS distribution flavor but not in another. We investigated Docker build, setcap, and libc, and found that the required capability was missing in nodes during the issue. The stack was complex, involving FIPS/CGO, build system, runtime configuration, and binary packaging in OVA. Debugging included CoreDNS binary, containerd, runc, SELinux, AppArmor, Photon OS, and the kernel... lots of learning which could be useful for many developers/admins or cluster operators to debug unprivileged pod execution. Finally, we discovered something interesting in the bootstrapping scripts. Let's debug.

Speakers

Akhil Mohan

Software Engineer, VMware by Broadcom

Akhil works as a Software Engineer at VMware by Broadcom. An active contributor to projects in cloud native and container ecosystem. Akhil is a maintainer of containerd, and the kubernetes publishing-bot sub project. He works mostly on container runtimes and kubernetes sig-node a... Read More →

Humble Devassy Chirammal

R&D Engineer, VMware by Broadcom

Humble is the Tech Lead for Kubernetes Distribution Engineering at VMware by Broadcom. He has more than 19 years of experience that includes extensive work in Openshift engineering, KVM Virtualisation..etc. He has led SDS based products while working at Red Hat. He is one of the... Read More →

Thursday December 12, 2024 11:30am - 12:05pm IST
201

Operations + Performance

Content Experience Level Intermediate

KubeCon + CloudNativeCon India 2024

Akhil Mohan

Humble Devassy Chirammal

Attendees (20)

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!