Ansible 2.17+ Dropped Python 3.6 Support: What EL8 Users Need To Know

The Python Version Dilemma for Ansible on EL8

If you're managing systems running on Enterprise Linux 8 (EL8), you might have encountered a rather inconvenient roadblock recently. The latest versions of Ansible, specifically Ansible 2.17 and newer, have officially dropped support for older Python versions, including Python 3.6. This change is a significant one, particularly for distributions like Red Hat Enterprise Linux 8, AlmaLinux 8, and Rocky Linux 8, which, by default, rely on Python 3.6 for many of their core functionalities. This means that if you're trying to use the newest Ansible versions with your EL8 systems, you're likely going to run into compatibility issues right out of the box. It's a common scenario where newer software versions, while offering exciting new features and performance improvements, inadvertently leave behind older, yet still widely used, operating system environments. The core of the problem lies in the fact that Ansible's modules, especially those interacting with the system's package management, are built upon specific Python interpreter versions. When these versions diverge, the modules can no longer execute correctly, leading to playbook failures and operational headaches. This isn't just a minor inconvenience; it directly impacts your ability to automate tasks, deploy applications, and manage your infrastructure effectively using the latest Ansible tools on a substantial segment of your server fleet.

Why Older Ansible Versions Are No Longer a Viable Option

When facing the Python compatibility challenge with Ansible 2.17+ on EL8, one might wonder if simply sticking with older Ansible versions is a sensible workaround. However, this approach quickly hits a dead end. The reality is that older versions of Ansible, particularly Ansible Core versions up to 2.16, are already End-of-Life (EOL). This means they are no longer receiving security updates, bug fixes, or feature enhancements from the Ansible community. Relying on EOL software is a significant security risk and can lead to unexpected behavior and instability in your automation workflows. Imagine discovering a critical vulnerability in your automation toolset and having no official patch available – that’s the precarious position you’d be in. Furthermore, as the Ansible ecosystem evolves, newer modules and features are introduced that are only compatible with the latest Ansible Core versions. By remaining on an older, EOL version, you lock yourself out of these advancements, potentially hindering your ability to adopt modern best practices or leverage new integrations. The development teams behind Ansible, like most software projects, must move forward. They focus their resources on supporting current and future versions, which necessitates deprecating support for older, less secure, and less efficient runtime environments. Therefore, while it might seem like a quick fix to stay on Ansible 2.16, it’s a short-sighted strategy that introduces more problems than it solves in the long run, especially concerning security and feature parity.

The Critical Dependency: python3-dnf and EL8's Python 3.6

The crux of the Ansible EL8 Python compatibility issue often boils down to a specific, yet critical, dependency: python3-dnf. On EL8 distributions, the native package manager, dnf, is intrinsically linked to Python 3.6. This means that Ansible modules designed to interact with dnf, such as the widely used ansible.builtin.package module (which internally utilizes ansible.builtin.dnf), require Python 3.6 to function. When Ansible 2.17+ attempts to run these modules on an EL8 system where only Python 3.6 is available for system-level package management, it fails because the newer Ansible versions are expecting a more recent Python interpreter. This creates a direct conflict. There isn't a readily available, officially supported alternative for python3-dnf via pip that would circumvent this dependency on EL8. While the Python Package Index (PyPI) does have a placeholder project for dnf, it doesn't offer a functional package that can replace the system's native python3-dnf module. This leaves automation engineers in a tough spot: how do you manage packages on EL8 using modern Ansible if the primary package management modules are incompatible? It highlights a common challenge in IT infrastructure: the tension between the rapid pace of software development and the slower, more stable release cycles of operating systems. EL8, while still supported, represents an older generation of Linux, and its default Python environment is precisely what newer tools are moving away from. Understanding this dependency is key to diagnosing and addressing the problem effectively.

Workaround: Leveraging ansible.builtin.command for Package Management

Given the incompatibility of the ansible.builtin.dnf module with newer Ansible versions on EL8 due to the Python 3.6 dependency, a practical workaround emerges: using the ansible.builtin.command module. Instead of relying on the higher-level ansible.builtin.package module (which calls ansible.builtin.dnf), you can bypass the problematic Python dependency by directly invoking the dnf command-line interface. This involves explicitly writing tasks like ansible.builtin.command: dnf install <package_name> within your Ansible playbooks. By using the command module, you're essentially telling Ansible to execute a shell command just as you would if you were logged into the server directly. This bypasses Ansible's Python interpreter requirements for module execution related to package management. While this method effectively gets the job done – installing, updating, or removing packages – it's important to acknowledge its limitations. Using command is generally less idempotent than using dedicated modules like package. This means you need to be more careful in how you structure your tasks to ensure they don't accidentally re-run or cause unintended side effects. You might need to add extra checks or use creates / removes arguments to ensure idempotency. However, in the immediate term, this workaround provides a viable path forward for managing packages on EL8 systems with Ansible 2.17+ without downgrading Ansible or compromising on security by using EOL versions. It’s a testament to the flexibility of Ansible that such workarounds are possible, allowing teams to adapt to evolving software landscapes.

Considering the Future: Dropping EL8 Compatibility?

The persistent issue of Ansible's Python 3.6 dependency on EL8 naturally leads to a broader strategic question: does it still make sense to maintain compatibility with these older EL8 systems within the pdns-ansible project? This isn't a decision to be taken lightly. EL8 distributions, while still functional, are reaching a point where their default Python environment is becoming a bottleneck for modern tooling. Supporting older environments often requires significant engineering effort, including writing and testing compatibility code, managing conditional logic within playbooks, and potentially limiting the adoption of newer Ansible features. On the other hand, dropping support for EL8 means alienating a segment of users who may not be able to immediately upgrade their operating systems due to various constraints – be it hardware limitations, application compatibility concerns, or simply long-term support contracts. The pdns-ansible role, in particular, relies heavily on python3-dnf, which is tied to Python 3.6 on EL8. As Ansible Core continues its progression, focusing on newer Python versions, the maintenance burden for supporting Python 3.6 will only increase. The community must weigh the benefits of wider compatibility against the costs of maintaining support for increasingly outdated platforms. The decision to drop EL8 compatibility would likely streamline development and allow the project to fully embrace the capabilities of newer Ansible and Python versions, but it requires careful consideration of the user base and their upgrade paths. It's a classic trade-off between cutting-edge development and legacy support.

Conclusion and Next Steps

The incompatibility between Ansible 2.17+ and Python 3.6 on EL8 systems presents a clear challenge for users of distributions like Red Hat 8, AlmaLinux 8, and Rocky Linux 8. With older Ansible versions being EOL and the critical python3-dnf dependency tied to Python 3.6, direct upgrades can halt automation efforts. The ansible.builtin.command: dnf install ... workaround offers a temporary solution, enabling package management by bypassing the problematic module. However, it comes with the caveat of needing careful handling to ensure idempotency. The strategic decision of whether to continue supporting EL8 in projects like pdns-ansible hinges on balancing development resources against user base needs. Ultimately, users on EL8 may need to consider their upgrade path to newer operating system versions that support more recent Python runtimes to fully leverage the capabilities of modern Ansible. For those who must remain on EL8, the workaround provides a way forward, but planning for OS upgrades should be a priority.

For further insights into managing Python environments and Ansible compatibility, consider exploring the official documentation from Red Hat and Ansible.