9c0af41710
For a long time we've cached the remote configs in the repo, which mostly makes sense for the `repo/config` file, but less sense for `/etc/ostree/remotes.d`, because we want to support admins interactively editing them. One can delete the repo instance and create a new one, but that's a bit ugly. Let's introduce an API for this so rpm-ostree can reload remotes after admins/scripts edit them in `/etc`. We also might as well reload any other entries in the config. Structurually now, `ostree_repo_open()` deals with file descriptors, and then calls `ostree_repo_reload_config()`. Except for the uncompressed cache, which is the only thing that deals with FDs that can be configured. But we want to delete that anyways. No tests, since...we don't have a daemon in this codebase, don't want to shave that yak just today. Closes: #662 Approved by: jlebon
libOSTree
New! See the docs online at Read The Docs (OSTree)
This project is now known as "libOSTree", renamed from "OSTree"; the focus is on the shared library. However, in most of the rest of the documentation, we will use the term "OSTree", since it's slightly shorter, and changing all documentation at once is impractical. We expect to transition to the new name over time.
libOSTree is a library and suite of command line tools that combines a "git-like" model for committing and downloading bootable filesystem trees, along with a layer for deploying them and managing the bootloader configuration.
The core OSTree model is like git in that it checksums individual files and has a content-addressed-object store. It's unlike git in that it "checks out" the files via hardlinks, and they should thus be immutable. Therefore, another way to think of OSTree is that it's just a more polished version of Linux VServer hardlinks.
Features:
- Atomic upgrades and rollback for the system
- Replicating content incrementally over HTTP via GPG signatures and "pinned TLS" support
- Support for parallel installing more than just 2 bootable roots
- Binary history on the server side (and client)
- Introspectable shared library API for build and deployment systems
This last point is important - you should think of the OSTree command line as effectively a "demo" for the shared library. The intent is that package managers, system upgrade tools, container build tools and the like use OSTree as a "deduplicating hardlink store".
Projects using OSTree
rpm-ostree is a tool that uses OSTree as a shared library, and supports committing RPMs into an OSTree repository, and deploying them on the client. This is appropriate for "fixed purpose" systems. There is in progress work for more sophisticated hybrid models, deeply integrating the RPM packaging with OSTree.
Project Atomic uses rpm-ostree to provide a minimal host for Docker formatted Linux containers. Replicating a base immutable OS, then using Docker for applications meshes together two different tools with different tradeoffs.
flatpak uses OSTree for desktop application containers.
GNOME Continuous is a custom build system designed for OSTree, using OpenEmbedded in concert with a custom build system to do continuous delivery from hundreds of git repositories.
Building
Releases are available as GPG signed git tags, and most recent versions support extended validation using git-evtag.
However, in order to build from a git clone, you must update the submodules. If you're packaging OSTree and want a tarball, I recommend using a "recursive git archive" script. There are several available online; this code in OSTree is an example.
Once you have a git clone or recursive archive, building is the same as almost every autotools project:
env NOCONFIGURE=1 ./autogen.sh
./configure --prefix=...
make
make install DESTDIR=/path/to/dest
More documentation
New! See the docs online at Read The Docs (OSTree)
Some more information is available on the old wiki page: https://wiki.gnome.org/Projects/OSTree
Contributing
See Contributing.