stratisd

A daemon that manages a pool of block devices to create flexible filesystems.

Background

Stratis (which includes stratisd as well as stratis-cli), provides ZFS/Btrfs-style features by integrating layers of existing technology: Linux's devicemapper subsystem, and the XFS filesystem. stratisd manages collections of block devices, and exports a D-Bus API. Stratis-cli's stratis provides a command-line tool which itself uses the D-Bus API to communicate with stratisd.

Documentation

https://stratis-storage.github.io/ currently has links to the main internal design doc, the D-Bus API Reference manual, and some coding style guidelines.

Getting involved

Communication channels

If you have questions, please don't hesitate to ask them, either on the mailing list or IRC! 😃

Mailing list

Development mailing list: stratis-devel@lists.fedorahosted.org, -- subscribe here.

IRC

irc.freenode.net #stratis-storage.

For Developers

Stratisd is written in Rust, which helps the implementation be small, correct, and avoid requiring shipping with a large language runtime.

Issue tracking and Development

Stratisd development uses GitHub issue tracking, and new development occurs via GitHub pull requests (PRs). Patches or bug reports may also be sent to the mailing list, if preferred.

Setting up for development

Development Compiler

The version of the compiler recommended for development is 1.40. Other versions of the compiler may disagree with the CI tasks on some points, so should be avoided.

Building

Stratisd requires Rust 1.38+ and Cargo to build. These may be available via your distribution's package manager. If not, Rustup is available to install and update the Rust toolchain. Once toolchain and other dependencies are in place, run make build to build, and then run the stratisd executable in ./target/x86_64-unknown-linux-gnu/debug as root. Pass the --help option for more information on additional developer options.

Building tests

The Makefile provides a target, build-tests which allows compiling the tests without running any of them, as a convenience to developers.

Secondary dependencies

The rust library dbus-rs has an external dependency on the C dbus library dbus development library. Please check with your distributions package manager to locate the needed package.

The files needed to build dbus-rs include, but are not limited to:

/usr/include/dbus-1.0/dbus/dbus*.h
/usr/lib64/libdbus-1.so
/usr/lib64/pkgconfig/dbus-1.pc

Also, the rust library libudev-sys has a dependency on the C libudev library. Please check with your distributions package manager to locate the needed package (e.g libudev-dev for Debian-based, systemd-devel for Fedora RPM-based Linux distributions).

At least, you need to include:

/usr/lib64/pkgconfig/libudev.pc

Formatting

Stratisd makes use of rustfmt to enforce consistent formatting in Rust files. PRs must pass the fmt task in the CI in order to be merged. Run make fmt to ensure your changes conform to the expected formatting before submitting a pull request. Formatting changes a bit with different versions of the compiler; make sure to use the current development version.

Linting

Stratisd makes use of clippy to detect Rust lints. PRs must pass the clippy task in the CI in order to be merged. To check for lints, run make clippy. The lints change a bit with different versions of the compiler; make sure to use the current development version.

Configuring

Stratisd runs as root, and requires access to the D-Bus system bus. Thus in order to work properly, a D-Bus conf file must exist to grant access, either installed by distribution packaging; or manually, by copying stratisd.conf to /etc/dbus-1/system.d/.

Testing

Stratisd is tested in two ways. The first way makes use of the Rust test infrastructure and has more access to stratisd internals. The second way makes use of the stratisd D-Bus interface.

Tests that make use of the Rust test infrastructure

Stratisd incorporates two testing modalities:

• safe unit tests, which can be run without affecting your storage configuration
• unsafe unit tests, which may create and destroy devices during execution

To run the safe unit tests:

$ make test

For a description of the unsafe unit tests, necessary setup steps, and how to run them, see tests/README.md.

Test that interact with stratisd via the D-Bus

For a description of the D-Bus-based tests see tests/client-dbus/README.rst.

Licensing

MPL 2.0. All contributions retain ownership by their original author, but must also be licensed under the MPL 2.0 to be merged.