torcx (pronounced "torks") is a boot-time manager for system-wide ephemeral customization of Linux systems. It has been built specifically to work with an immutable OS such as Container Linux by CoreOS.
torcx focuses on:
- providing a way for users to add additional binaries and services, even if not shipped in the base image
- allowing users to pin specific software versions, in a seamless and system-wide way
- supplying human- and machine-friendly interfaces to work with images and profiles
This project provides a very lightweight add-ons manager for otherwise immutable distributions. It applies collections of addon packages (named, respectively, "profiles" and "images") at boot-time, extracting them on the side of the base OS.
Profiles are simple JSON files, usually stored under /etc/torcx/profiles/ with a .json extension, containing a set of image-references:
{
"kind": "profile-manifest-v1",
"value": {
"images": [
{
"name": "foo-addon",
"reference": "0.1",
"remote": "com.example.foo"
}
]
}
}
Image archives are looked up in several search paths, called "stores":
- Vendor store: usually on a read-only partition, it contains addons distributed together with the OS image
- User store: usually on a writable partition, it contains images provided by the user
- Runtime store: additional search path specified at runtime
At boot-time, torcx unpacks and propagates the addons defined in the active profile, specified in /etc/torcx/next-profile.
Once done, torcx seals the system into its new state and records its own metadata under /run/metadata/torcx.
torcx is released under the Apache 2.0 license. See the LICENSE file for all details.