A fuse filesystem that proxies all requests to a given directory, but pipes the contents of a file through a command on read. This is useful, for example, for transparently decrypting files.
Create a source directory (e.g. src).
Create a mountpoint (e.g. dst).
A proof of concept example, that fully proxies files
python command_fs.py src dst cat
An example to base64 encode files
python command_fs.py src dst base64
An example to decrypt all files with gpg
python command_fs.py src dst "gpg --decrypt"
An example to inject all files with 1password
python command_fs.py src dst "op inject -i /dev/stdin"