How do you make operating system containers work everywhere?

1 What are operating system containers?

Operating system containers are a type of virtualization that allows you to run multiple applications on a single host without creating full-fledged virtual machines. Instead of emulating a whole operating system, containers share the kernel and libraries of the host, but isolate the application processes and resources. This makes them lightweight, fast, and efficient. Containers can run on any platform that supports the same kernel and libraries, such as Linux, Windows, or MacOS.

2 How do containers differ from virtual machines?

Virtual machines are another type of virtualization that creates a complete operating system environment for each application. They use a hypervisor to emulate the hardware and run the guest operating system on top of the host operating system. This adds a layer of abstraction and overhead, but also provides more flexibility and compatibility. Virtual machines can run any operating system, regardless of the host, such as Windows on Linux or Linux on Windows.

3 Why do you need cross-platform compatibility for containers?

Cross-platform compatibility for containers allows you to run the same container image on different platforms without changing the code or configuration. This can be beneficial for developing and testing applications on different environments, deploying and scaling applications on different cloud providers or platforms, migrating and updating applications without downtime or compatibility issues, and sharing and collaborating on applications with other developers or users.

4 What are the challenges of cross-platform compatibility for containers?

Cross-platform compatibility for containers is not always simple to attain, as they are reliant on the kernel and libraries of the host operating system. This means that if the host operating system differs from the one used to create the container image, the container may not run correctly or at all. For instance, a Linux container cannot be executed on a Windows host and vice versa. Some of the common difficulties of cross-platform compatibility for containers include various kernel features and capabilities, varying library versions and dependencies, distinct file systems and paths, different network and security settings, as well as various user and group permissions.

5 How do you achieve cross-platform compatibility for containers?

Achieving cross-platform compatibility for containers can be accomplished in several ways. Docker is an example of a universal runtime engine that can run containers on any platform that supports it, while OCI is an example of a multi-platform container image format that can store and distribute containers for different platforms. BuildKit is an example of a cross-platform container builder that can create containers for different platforms. Additionally, LCOW is a hybrid container solution that can run Linux containers on Windows hosts, and LXD is a nested container solution that can run containers inside virtual machines.

6 What are the best practices for cross-platform compatibility for containers?

Achieving cross-platform compatibility for containers can be a difficult but rewarding task. To make the process easier and more effective, you should consider following best practices such as selecting the proper platform and tools for your use case and requirements, testing and debugging your containers on various platforms before deployment, using consistent and standardized naming and tagging conventions for your container images, documenting and communicating your container specifications and dependencies, and updating and maintaining your containers regularly and securely.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?