为何Puppet使用不同Ruby版本？CentOS 6.5下Puppet 3.8.7为何用Ruby 1.8？

Your setup makes total sense once you look at the compatibility choices Puppet made back in the 3.x era. Here's the breakdown:

• CentOS 6.5 ships with Ruby 1.8.7 as its default system Ruby. Puppet 3.x was intentionally built to support this version because it aimed to work seamlessly with older enterprise Linux distributions (like RHEL/CentOS 6) without forcing users to upgrade their system Ruby—something that's often risky or restricted in enterprise environments.
• Puppet 3.x's codebase was fully compatible with Ruby 1.8.7. The development team hadn't yet adopted features from newer Ruby versions that would break compatibility with 1.8, so sticking to the system's default Ruby was a practical choice for broad adoption.

Puppet's Ruby version requirements shift for a few key reasons:

• Platform alignment: Puppet prioritizes working with the default Ruby versions provided by popular operating systems. For example:
  • Older enterprise distros (CentOS 6, RHEL 6) use Ruby 1.8 → Puppet 3.x supports it.
  • Mid-tier distros (CentOS 7, RHEL 7) use Ruby 2.0/2.1 → Puppet 4.x+ targets these.
  • Modern distros (CentOS 8+, Ubuntu 20.04+) use Ruby 2.5+ → Puppet 6.x+ and newer align with these.
• Feature adoption: As Ruby evolved, newer versions introduced performance improvements, safer syntax, and useful libraries. Puppet's development team started leveraging these in later releases—for example, Puppet 4.x dropped Ruby 1.8 support because it relied on features like keyword arguments and improved garbage collection that weren't available in 1.8.
• Security & support: Ruby 1.8 reached its end-of-life in 2013, meaning no more security patches. Puppet had to move to supported Ruby versions to ensure the tool itself remained secure and stable. Newer Puppet releases only support Ruby versions that are still receiving official updates.
• Performance gains: Newer Ruby versions are significantly faster than 1.8. For Puppet, which runs complex catalog compilations and agent checks, upgrading Ruby directly improves the tool's overall speed and reliability.

内容的提问来源于stack exchange，提问作者pitmod