How to delete all subdirectories except a few?

Question

Using Ansible, I need to ensure, all of the subfolders of a certain directory do not exist except for a few, that must be retained.

The list to be kept will be specified externally -- say, as subfolders_to_keep.

The only way I can see is to first use the find-module to enumerate the subdirectories, and then, using file, delete all, that aren't exceptional -- in a loop.

That would be a fairly long loop here — of the 50-plus entries, only 4 are to survive. Perhaps, there is a more elegant way?

Answer 1

That would be a fairly long loop here

Right, with significant performance effects. See in example Ansible: How to optimize running speed of a playbook? or How do I optimize performance of Ansible playbook?

There is a more elegant way?

Since there is no out-of-box module available for such kind of tasks, in your specific Use Case

• Using shell module – Execute shell commands on targets with find or rm together with excludes. See in example
  • How to delete all files in a directory except some?
  • Delete files and exclude some with find
• Writing a short script and using the script module – Runs a local script on a remote node after transferring it. Maybe read before about How to execute a shell script on a Remote Server using Ansible?.
• Developing an own Custom Module. An example in Pyhton can be found under Custom Module library/pygrep.py. Shell or Bash is also possible but probably more complex. An example can be found under Example Module between.sh.