CombinedFS stands for Completely Over-engineered, Melted Brain-Induced, Not Even Decent Fucking Solution.
Well, no, it doesn't, but I like far-fetched acronyms.
CombinedFS is a FUSE FileSystem that exposes a transformed, straightforward, read-only version of Let's Encrypt / Certbot's "live" directory for better integration with software that requires "combined" PEM files.
- Dynamically concatenate and expose adequate PEM files;
- include PEM files from outside the Certbot directory, e.g. Diffie-Hellman parameters;
- hide symlinks, resulting in a single directory to expose to your TLS frontend;
- filter exposed certificates (whitelist / blacklist) using a regular expression;
- expose either a Certbot-like tree (e.g. my.domain.tld/combined.pem), suitable for those who just need filtering or concatenation...
- or a flattened directory (e.g. my.domain.tld_cert.pem), suitable for software that loads all PEM files in a given directory;
- specify Unix permissions: uid, gid, mode, either globally or on a per-file basis (not a per-cert basis though).
- Python with [fusepy](https://github.com/fusepy/fusepy)
- YAML/JSON configuration file
## How to use it
combinedfs.py [--foreground] /path/to/configuration.yaml /mount/point
/path/to/configuration.yaml /mount/point fuse.combinedfs defaults 0 0
Refer to `configuration.reference.yaml` to write your own configuration file.
Certbot already offers hooks to handle pretty much everything, from mere concatenations to complex deployments to various kinds of clusters.
So why write a Fuse FileSystem to cover only a small part of this scope?
Well, duh. Because it's fun, here's why.