In the ever-evolving landscape of technology, staying agile is paramount. However, many projects find themselves bound by legacy systems, libraries, or outdated server architectures that hinder progress, limit flexibility and prevent applying security patches. Such was the case for one of our clients, whose infrastructure relied on an outdated library. This dependency not only blocked crucial system upgrades but also locked the project into a specific, outdated server architecture. Our team was called upon to solve this complex problem without overhauling the entire infrastructure.

The Challenge: Outdated Library Dependency

The client’s system was utilizing an old service that was critical to its operations. However, development had stopped on this service a long time ago. This created a significant obstacle:

• Upgrade Roadblocks: The project couldn’t be upgraded due to compatibility issues with newer libraries and architectures.
• Server Architecture Lock-in: The system was tied to a specific, outdated architecture, making it impossible to scale or shift to newer, more efficient platforms.
• Risk and cost of Major Refactoring: While a common solution might be to extract the old library into a separate service or refactor large portions of the system, this approach would have demanded significant time, budget, and testing resources.

The Solution: Dockerizing a part of the application using QEMU

Our innovative solution was to introduce a Docker container that could simulate the legacy environment without altering the core infrastructure. By utilizing QEMU, we were able allow the legacy service to run seamlessly in its required environment while allowing the rest of the app and infrastructure to be upgraded to the latest versions.

Key components of our solution included:

• Docker Containerization: By encapsulating the legacy environment in a Docker container, we were able to isolate the outdated library and its dependencies without impacting the rest of the infrastructure. This allowed for the creation of a modular, flexible, and easily deployable solution.
• QEMU Emulation: To tackle the architecture lock-in, we used QEMU to emulate the older server architecture within the Docker container. This allowed us to run the old library in its original environment without needing to modify or refactor the existing codebase to any large extent and still allow the rest of the app to be migrated to run on a much more efficient platform.

Addressing Rollout Challenges: Overcoming QEMU Issues

During the initial rollout phase, we encountered an unexpected issue. The solution had been developed and tested on macOS using Rosetta2 for architecture emulation, but the production environment used QEMU on Linux servers. When deploying the solution on Ubuntu 24.04, we discovered that the version of QEMU shipped with the distribution was unstable and outdated, leading to segmentation faults that interrupted the service’s functionality.

After quickly pinpointing the segmentation faults to QEMU the version was upgraded to the latest compatible and stable release version QEMU. This immediately eliminated the segmentation faults, allowing for smooth execution within the Docker container.

Key steps in the resolution:

• Root Cause Analysis: We identified that the older QEMU version was the cause of the segmentation faults by comparing behavior between macOS with Rosetta2 and the Linux production environment.
• Upgrade QEMU: By upgrading QEMU to the latest stable version, we resolved the compatibility issues and restored stable operation within the containerized environment.
• Ensured Stability: After extensive testing it was verified that the upgraded QEMU version provided long-term stability and the problem fixed.

The Impact: Seamless Upgrades and Future-Proof Infrastructure With our solution in place, the client was able to:

• Unlock Infrastructure Flexibility: By removing the architecture lock-in, the project could now be run on modern server environments without being tied to legacy hardware.
• Enable Future Upgrades: With the old library contained and isolated, the rest of the system was free to be upgraded, allowing the client to stay on top of technological advancements.
• Avoid Major Refactoring: Our solution avoided the need for a time-consuming and costly refactor, preserving the existing structure while eliminating the dependency bottleneck.

We can help!

This project is a good example of stable out-of-the-box solutions that we are able to create. We don’t just look for quick fixes; we engineer stable, efficient, scalable solutions that address both current needs and future flexibility.

By leveraging Docker and QEMU, we demonstrated our expertise in modern containerization and virtualization technologies, coupled with a deep understanding of legacy systems and how to integrate them into future-proof infrastructures. Even when faced with unforeseen challenges during rollout, our team’s agility and expertise ensured a smooth transition to production.

Our client now enjoys a system that is agile, upgradeable, and scalable—without the burden of legacy dependencies.

If your project is facing similar challenges, reach out to us. We specialize in unlocking your infrastructure’s potential, ensuring you can keep pace with the future.