Navigating Updates and Security in a Containerized World
Tags: devops, docker, security, cloud
Published: 2024-01-27 17:53:43

The [adoption](https://www.enterprisestorageforum.com/software/container-registry-market/) of [container technology](https://link.springer.com/article/10.1007/s13369-021-05553-3) is rapidly gaining momentum among software developers and organizations. Two key attributes contribute to the success of containers. Firstly, they provide an exceptionally convenient method for distributing and running software through self-contained executable images. These images encompass all necessary libraries and dependencies, offering a lightweight alternative to traditional VM images. Secondly, containers ensure a robust level of security and isolation by utilizing kernel namespaces to execute processes within their designated [jail](https://docs.freebsd.org/en/books/handbook/jails/). This includes isolation of mounts, PID, network, IPC, and more. Additionally, containers [implement resource limitations](https://blog.kubesimplify.com/understanding-how-containers-work-behind-the-scenes#heading-control-groups-cgroups) for CPU usage and memory through kernel cgroups, while maintaining standard kernel security mechanisms for memory protection and permission enforcement.


Container images are frequently updated, typically to incorporate new features or to fix security vulnerabilities. Updates that introduce new features are more common, but those prompted by security concerns are acted upon with greater urgency.


![Container Runtime](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/92hhe4i1ml8e1lo3hbn3.png)


Consider a standard containerized environment depicted above. While updating underlying server hardware and the host operating system is relatively straightforward, updating containerized applications is a more complex and error-prone endeavor. Simply updating the base operating system image of a container is not enough to ensure the application image is also updated. Due to the immutable nature of containers, any change necessitates rebuilding all subsequent layers of the container image, preventing a simple update process.


![Propagation of updates from changes in base image](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/evrwigrol3nrlzk8a6mg.png)



Several practical issues arise from the immutable nature of container images, such as:

- Frequent updates to the base OS image, and the challenge of consistently rebuilding the application images in response.
- Dependencies on specific versions of the base image, leading to potential vulnerabilities if the base image isn't updated.
- Risks associated with security patches to the base image potentially breaking the application.
- Complexities in managing and remembering the rebuild sequence for intermediary images.
- The logistics of informing all affected developers of the need to rebuild their images, and verifying their compliance.

These challenges underscore the necessity for a comprehensive, automation platform to streamline the update process for container images. Such a platform should not only facilitate productivity gains for software teams but also integrate seamlessly with existing enterprise tools infrastructure, including security, repositories, continuous integration/continuous deployment (CI/CD), and messaging systems, to enhance the efficiency of adjacent workflows.

In upcoming posts, I'll detail a novel solution to these challenges. Your questions and comments are welcome, as they will contribute significantly to our ongoing discussion of this critical topic.