Why Use Ubuntu as a Docker Base Image?

Summary

• A Balanced Foundation: Ubuntu base images strike a strategic middle ground between “fat” desktop distributions and ultra-minimalist options like Alpine, weighing in at approximately 75 MB.
• Extensive Ecosystem: Developers gain immediate access to the Apt package manager and over 60,000 software packages, significantly reducing the time spent manual-coding dependencies.
• Production Stability: Built on glibc (the standard C library), Ubuntu ensures high compatibility for Python, Node.js, and Java applications, avoiding the subtle runtime bugs often found in minimalist libraries.
• Enterprise Security: While larger than Alpine, Ubuntu provides a predictable LTS (Long Term Support) lifecycle with rapid security patching and deep integration into vulnerability scanning tools like JFrog Xray.
• Developer Friendly: By using the same environment from local development to cloud production, teams reduce “it works on my machine” errors and streamline troubleshooting.

Overview of Ubuntu Base Images

When developers debate which base image to use, the conversation often centers on minimalism versus balance of size and functionality. In community discussions like this Reddit thread and common StackOverflow questions, one theme emerges: Context matters. Although there may be  smaller alternatives,  Ubuntu’s extensive library of tools, mature ecosystem, and wide adoption across industries make it a dependable foundation. For developers who want a base image that works reliably across most use cases without endless patching or customization, Ubuntu remains a strong candidate.

In some situations, however, it makes sense to select the leanest base image possible, as  base images that are smaller result in faster build operations. They also are more secure, in the sense that they have a smaller attack surface.

That doesn’t mean, however, that smaller is always better when selecting a base image. To prove the point, this article walks through the differences between two fundamentally distinct types of base images: Those based on Ubuntu Linux and those based on Alpine Linux.

As we’ll see, although neither base image is inherently better than the other, each is better suited to certain use cases. You shouldn’t necessarily choose Alpine over Ubuntu just because Ubuntu is a larger base image.

Why Choosing the Right Base Image Matters

Choosing the right base image for your container is one of the first steps in successfully containerizing an application. The type of base image you select should take into account the following considerations:

• Dependencies: If the dependencies that your application requires to run are included in the base image, you don’t have to do as much work when configuring your Docker image by adding custom commands to your Dockerfile.

• Extensibility: Having more dependencies and other resources built into the base image also makes it easier to update your containers over time without having to modify Dockerfiles.

• Security: The fewer components you have in your base image, the lower the risk that the image will contain a vulnerable library or another resource that attackers could exploit.

• Image “Bloat”: Using a needlessly large base image can lead to image bloat, meaning container images that are large – and therefore take longer to download – because they contain components that the application doesn’t need.

To select the best base image for your application, you need to find the balance between the number of resources included in the image and  the overall size of the image. These tend to be competing priorities because the more utilities and libraries you include in your base image, the larger the base image will be.

In general, base images fall into two main categories:

• Base images that are created using full-scale operating systems, like Ubuntu
• Images based on minimalist operating systems, like Alpine Linux

Using Ubuntu and Alpine as examples, let’s compare each type of base image and weigh its pros and cons.

Using Ubuntu as a Base Image

Ubuntu base images, which can be  found on Docker Hub, are created using the root file system of the Ubuntu Base, a variant of the Ubuntu Linux operating system.

It’s important to note that Ubuntu Base is a lighter-weight version of Ubuntu than you would get if you installed the desktop version of Ubuntu on your machine. Ubuntu Base doesn’t contain the software necessary to run a graphical interface, office software and other utilities that are irrelevant for most container use cases. So, even when you use Ubuntu as a base image, you get a relatively lean image; current Ubuntu base images are under 75 megabytes in size.

Nonetheless, if you run the Ubuntu 20.04 base image and view the contents of the /bin directory, you’ll see there are 294 utilities in the /bin directory in Ubuntu’s base image. All of this software is available in the Ubuntu base image by default, with no need on the part of developers to add it.

How to Work with Base Images

Ubuntu

To use Ubuntu as a base image for your container, first create a Dockerfile that identifies Ubuntu as the image.

If you wanted to install additional software and include it in your container, you’d set up the Dockerfile to run apt and install the desired packages.

Alpine

If you opt to use an Alpine base image, you simply create a Dockerfile.

If you need to install additional software, you can do so using apk, Alpine’s package manager.

With your Dockerfile properly configured, go ahead and build your container as you normally would.

What are the advantages of Ubuntu vs. Alpine?

Thanks in part to this expansive collection of built-in tools, Ubuntu base images offer certain advantages over truly minimalist base images, like Alpine:

• More tools: Ubuntu base images include more libraries and utilities by default. This reduces the amount of software that you have to install on top of the base image when building your own container image.

• Apt by default: Apt, the Ubuntu package manager, is built into the Ubuntu base images. You can use apt to install additional software from Ubuntu’s 60,000 packages when creating a container. Alpine Linux offers a package manager, too, but it does not have access to as many packages as apt.

• Widespread support: Ubuntu is one of the most popular Linux distributions, and it is widely used not just for running containers but for a variety of other purposes. This means that Ubuntu is likely to be familiar to developers and sysadmins, even if they have not used Docker before. Alpine Linux is less common outside the context of Docker.

What are the Advantages of Alpine vs. Ubuntu?

While an Ubuntu base image is advantageous in many ways, Alpine Linux can be a better choice in some situations. The disadvantages of Ubuntu as compared to Alpine include:

• Larger image size: Alpine base images total around 5.5 megabytes – much smaller than the approximately 75 megabytes that Ubuntu takes up. As a result, containers created using Alpine as a base image will also be smaller. In turn, Alpine-based containers will take less time to download, scan and (in most cases) run.
• Broader attack surface: Because Ubuntu base images include many more utilities and libraries by default than Alpine, they carry a higher security risk.

To get a sense of how much smaller Alpine is, there  are a total of 81 utilities in /bin – not an insignificant number, but still much fewer than Ubuntu’s 294.

On further inspection, most of Alpine’s utilities are actually just symbolic links to BusyBox, an executable that provides a number of Unix tools inside a single application

From a technical perspective, Alpine really contains just one utility – BusyBox. In that sense, Alpine is even leaner and easier to secure, because the only vulnerabilities you have to worry about are ones that affect BusyBox. That’s not the case in Ubuntu, where each of the hundreds of tools installed by default could be subject to any number of vulnerabilities.

The bottom line: In use cases where security is a top priority, or where your application has very few dependencies, it makes more sense to use Alpine as a base image than Ubuntu or a similar “full-weight” Linux distribution.

Is it Efficient to use Ubuntu as a Base Image?

Ubuntu base images strike a balance between efficiency and capability. While Alpine’s tiny footprint is smaller, Ubuntu is still lean compared to full desktop distributions, making it practical for production workloads. Teams that value predictable startup times and stable performance often prefer Ubuntu, since its extra libraries and tools reduce the need for custom build steps.

Real-world insights, like those shared in the Octopus blog on using Ubuntu Docker images, emphasize that Ubuntu’s slightly larger footprint pays off in fewer surprises during builds and deployments. Developers on ServerFault also highlight how its base images avoid the overhead of bolting on missing dependencies, ultimately saving time and resources. In this way, Ubuntu keeps container operations efficient without sacrificing functionality.

How Flexible is Ubuntu?

Flexibility is one of  Ubuntu’s  strongest features. Developers can easily extend an Ubuntu base image with the apt package manager, which provides access to over 60,000 software packages. This makes it straightforward to configure images for everything from Python or Node.js applications to full enterprise stacks.

As AskUbuntu contributors note, the key difference between Ubuntu as an operating system and as a Docker image is that the latter strips away unnecessary components while keeping the essentials developers rely on. On DevOps StackExchange, practitioners point out that this flexibility makes Ubuntu a better fit than application-specific images for projects that evolve quickly. Even individual developers, such as in this blog post by Kronis, stress how Ubuntu’s compatibility with existing infrastructure and workflows helps it scale seamlessly from small projects to enterprise deployments.

Securing Base Images with JFrog

Ubuntu offers a powerful balance of functionality and flexibility as a Docker base image, while Alpine delivers minimalism and speed. But whichever you choose, the real challenge isn’t just size or convenience – it’s making sure the packages and dependencies inside those images are secure.

JFrog Xray integrates directly with your container registries and CI/CD pipelines to scan Ubuntu- or Alpine-based images for vulnerabilities, license compliance, and risky dependencies. With Xray, teams can confidently use the base image that fits their workflow, without sacrificing security or compliance as they scale.

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