The Role of Snap Packages in Modern Application Deployment

Today, software distribution must do more than simply run—it must also be portable, secure, and system-independent. This is where the Snap technology comes into play.

Snap is a modern packaging system developed by Canonical. Canonical is also the creator of the Ubuntu operating system and one of the most important players in the open source world. Another key component of the Snap ecosystem is Snapcraft, an official tool also developed by Canonical that enables developers to build, test, and distribute Snap packages via the Snap Store.

In short, Snap applications are packaged using Canonical’s Snapcraft tool, published on the Snap Store, and made available to run identically across hundreds of Linux distributions.

In this article, we will examine in detail, from a scientific perspective, how the Snap packaging system works, which security and isolation techniques it employs, and the advantages it offers to developers and users.

Snapcraft Logo (Canonical Snapcraft)

The Role of Snap Packages in Modern Application Distribution: Isolation, Security, and Platform Independence

In traditional software distribution systems, applications require specific versions of libraries and tools to be present on the system. However, this often leads to a serious problem known as “dependency hell.” The Snap packaging system addresses this issue with a modern, secure, and platform-independent solution, opening the door to a new era in software distribution.

1. Dependencies as Part of the Package: Isolated and Portable Applications

Unlike classical packaging systems, Snap packages come bundled with all their dependencies. That is, a Snap application contains within itself the libraries and executables it needs to run, such as glibc and Python. This ensures the application runs stably, completely independent of the system’s existing library versions.

Scientific Note: This approach resembles the isolation principle used in containerization technologies. Although the application runs directly on the operating system, it executes within its own encapsulated environment, increasing portability while reducing interaction with the host system.

Advantages:

• Multiple versions of the same application can run simultaneously without dependency conflicts.
• System updates or changes to other packages do not disrupt the application’s functionality.
• Developers can distribute their software without being tied to specific system configurations.

2. Security and Isolation: Snap’s Sandbox Approach

Snap packages employ various isolation layers to restrict applications’ access to system resources. This architecture is particularly important from a security standpoint. Snap’s sandbox model is built on the following components:

a. AppArmor Profiles

AppArmor is an access control system integrated into the Linux kernel. Snap generates a unique AppArmor profile for each application. This profile:

• Specifies which files the application can access,
• Defines which network resources it can use,
• Determines which system calls are permitted.

As a result, even a malicious application cannot damage sensitive areas of the system.

b. Mount Namespaces

Snap provides each application with an isolated file system environment using mount namespaces. Thanks to this mechanism:

• The application can only see its own Snap file system.
• Access to the rest of the system’s file hierarchy is restricted.

c. Control Groups (cgroups)

Cgroups are a technology used to limit applications’ hardware resource usage. Snap uses this to:

• Prevent applications from excessively consuming CPU, memory, and disk I/O resources.
• Ensure fair sharing of system resources.

d. Seccomp Filtering

Snap uses the seccomp mechanism to filter system calls that an application can make. This prevents potentially harmful system operations from being executed.

Additional Security Layer: Snap applications run only with user-level privileges; root access is blocked. Even if you attempt to run a Snap application with “sudo,” your permissions are still restricted by the snap-confine helper program, adding another layer of security.

3. Platform Independence: The Role of Base Packages

The Snap ecosystem uses base packages to enable the same applications to run across different systems. These base packages provide the core system components required by applications.

Key base packages include:

• core: A minimal Ubuntu system.
• core18: Based on Ubuntu 18.04.
• core20: Based on Ubuntu 20.04.

Applications are packaged against these bases, allowing the same Snap package to run unchanged on different systems such as Fedora, Debian, or Arch Linux.

4. File System Isolation: The /snap Directory Structure

Snap packages are distributed as compressed, read-only file systems in squashfs format. These packages are mounted under the /snap/<package_name>/<version> directory on the system.

Example:

If an application requires glibc, it uses it from its own /snap/... directory rather than from the system’s /usr/lib. This eliminates the risk of conflicts with the system-wide file system.

This structure ensures:

• File system manipulation is prevented.
• System integrity is preserved.
• Snap packages operate only from their own directories, making them predictable and controllable.

5. Easy and Secure Updates: Atomic and Delta Approaches

The Snap package manager employs modern techniques for updating applications.

a. Delta Updates

Snap updates applications by downloading only the changed files. This saves both bandwidth and time.

b. Atomic Updates

Update operations are performed atomically:

• The old version continues to run until the new version is fully installed.
• If the update fails, the system automatically rolls back to the previous version.

c. Parallel Version Management

Snap allows multiple versions of the same application—such as stable, beta, or edge—to run simultaneously. Since each version operates in its own isolated environment, conflicts do not occur.

Why Is Snap Important?

Snap provides a comprehensive solution for modern software distribution:

• For developers: The ability to package an application once and run it everywhere.
• For users: Access to secure, stable, and up-to-date software.
• For system administrators: Control over application dependencies and enhanced system security.

The Snap technology is an effective model that brings container-like principles to desktop applications. In the evolving software landscape, it offers a powerful alternative for anyone seeking platform independence, security, and ease of use.