Copa: Patching Container Images Without a Rebuild
Shriira Press
Patch the operating-system vulnerabilities in a container image directly, in seconds, without waiting for a rebuild.
Welcome to Copa: Patching Container Images Without a Rebuild.
Copacetic, known on the command line as copa, is a CNCF sandbox project and a small Go CLI tool built on BuildKit that closes the painful gap between learning about a vulnerability and actually fixing it. Instead of rebuilding an entire image from source and waiting on an upstream publisher, Copa reads a vulnerability scan report, works out exactly which operating-system packages need updating, fetches and applies only those updates, and writes a new patched image with a single extra layer. This book follows that idea from the ground up. We begin with the remediation problem Copa exists to solve, then trace the scan-parse-apply pipeline at its heart. We look at how BuildKit's diff and merge machinery produces a clean patch layer, how the copa patch command fits into a Trivy workflow, and how a clever tooling-container trick lets Copa patch even distroless and multi-platform images. We finish with Copa's extensibility through scanner plugins and VEX output, and how teams wire it into real CI/CD pipelines. By the end you will understand not just how to run Copa, but why it works the way it does.
This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.
A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.
We hope it serves you well.
— Shriira Press