mode: preserve can be misleading/misunderstood, deprecate it and offer mode: preserve_src and mode: preserve_dest

[wookietreiber]

SUMMARY

IMHO, mode: preserve is misleading and can be misunderstood. That is because the name by itself does not clearly specify which mode is to be preserved, the source or the destination. In my case, my intuition led me to believe that the mode on the destination is preserved. It would be more explicit/clear if it were named mode: preserve_src.

I know that the documentation says that it preserves the source mode. The issue is more about the first impression of what the name preserve suggests and that this can be misleading without having read the documentation (which if we're all honest not everyone immediately does). Especially, with the recent addition to ansible-lint to issue a warning about missing mode:

Missing mode parameter can cause unexpected file permissions based on version of Ansible being used. Be explicit, or if you still want the default behavior you can use mode: preserve to avoid hitting this rule. See #71200

With that, one is tempted to use mode: preserve, possibly assuming that it would preserve the mode of the destination.

(Personally, I don't even get why someone would preserve the mode of the source. Especially when I'm changing a config file that is originally deployed with the distributions package manager, shouldn't I always want to preserve the destination mode?)

ISSUE TYPE

• Feature Idea

COMPONENT NAME

• template
• copy
• all other modules using mode argument

[ansibot]

Files identified in the description:

• lib/ansible/cli/__init__.py
• lib/ansible/modules/copy.py
• lib/ansible/modules/template.py

If these files are incorrect, please update the component name section of the description or use the !component bot command.

click here for bot help

[samdoran]

The start of this confusion stems from a bad recommendation by the ansible-lint rule. It should not be suggesting mode: preserve since that only works in two modules. We are actually in favor of removing this rule altogether since it causes so much confusion and should no longer be necessary.

I know that the documentation says that it preserves the source mode. The issue is more about the first impression of what the name preserve suggests and that this can be misleading without having read the documentation (which if we're all honest not everyone immediately does).

I understand how the name could be interpreted different ways before reading the documentation for clarification. Changing the name to preserve_src would make sense to you, but may just as easily confuse others. I'm not saying your interpretation is wrong, but that it is just that: your interpretation.

The documentation does clarify the behavior. I understand most folks do not read documentation, but changing the name would not remove the need to read the documentation for further clarification on the exact behavior.

To discuss this further, please reach out on IRC or the mailing list:

   * IRC: #ansible-devel on irc.freenode.net  
   * mailing list: https://groups.google.com/forum/#!forum/ansible-devel