# Building Scylla

This document describes how to build Scylla's executables, tests, and packages.

*Please note that these instructions use `dbuild` -- a Docker-based development environment -- to build Scylla.
However, `dbuild` is optional and you can also build on your host machine by running the same commands without the `dbuild` prefix.*

## Table of Contents

* [Getting Started](#getting-started)
* [Configuring](#configuring)
* [Building](#building)
* [Packaging](#packaging)
* [Artifacts](#artifacts)

## Getting Started

To build everything, run:

```console
git clone https://github.com/scylladb/scylla
cd ./scylla
git submodule update --init --force --recursive
./tools/toolchain/dbuild ./configure.py --mode=<mode>
./tools/toolchain/dbuild ninja
```

where `mode` is `dev` for development builds, `release` for release builds, and `debug` for debug builds.

Alternatively, you can also pass the `mode` directly to the `ninja` command:

```console
git submodule update --init --force --recursive
./tools/toolchain/dbuild ./configure.py
./tools/toolchain/dbuild ninja <mode>
```

After the build completes, you can find build artifacts in `build/<mode>` directory.

You can run unit tests with:

```console
./tools/toolchain/dbuild ninja test
```

or launch a Scylla server locally with:

```console
./tools/toolchain/dbuild ./build/dev/scylla --workdir tmp --smp 1 --memory 1G
```

For more help with build targets, run:

```console
./tools/toolchain/dbuild ninja help
```

That's it!

## Configuring

The `configure.py` script, which is run as the first step of a build, generates a `build.ninja` build file (similar to a `Makefile`) for the [Ninja] build tool that we use for building.

To configure the build system for a specific build mode, run:

```console
./tools/toolchain/dbuild ./configure.py --mode=<mode>
```

The `mode` flag determines build flags for the `scylla` executable:

* `release` is the release build that targets fast execution time (slow build, fast execution).
* `dev` is the development build that targets fast build times (fast build, reasonable execution)
* `debug` is the debug build that targets error discovery (slow build, slow execution).

If you don't specify a build mode, the `build.ninja` will contain configuration for _all build modes_.

[Ninja]: https://ninja.org/

## Building

To build Scylla executables and tests, run:

```console
./tools/toolchain/dbuild ninja build
```

This will build Scylla for the build mode specified by the `configure.py` command.

Alternatively, if you did not specify a build mode in the `configure.py` step, you can build executables and tests for a specific build mode with:

```console
./tools/toolchain/dbuild ninja <mode>-build
```

## Testing

To run unit tests, run:

```console
./tools/toolchain/dbuild ninja test
```

Alternatively, to run unit tests for a specific build mode, run:

```console
./tools/toolchain/dbuild ninja <dev>-test
```

## Packaging

The build system generates _relocatable packages_, which means that the packages contain all the dependencies they need, and you can, therefore, install and run the same binaries on all Linux distributions.
The relocatable package tarball is used as a base for building the Linux distribution specific packages, `.rpm`s and `.deb`s.

To build packages, run:

```console
./tools/toolchain/dbuild ninja dist
```

Alternatively, to build packages for a specific build mode, run:

```console
./tools/toolchain/dbuild ninja <mode>-dist
```

To verify the packages, run:

```console
ninja dist-check
```

*Please note that you need to run `dist-check` on the host because it requires Docker to perform the verification.*

## Artifacts

This section lists all the artifacts generated by the build system.

**Executables**:

* `build/<mode>/scylla`

**Tests**:

* `build/<mode>/test/**`

**Tarballs**:

* `build/<mode>/dist/tar/scylla-unified-package.tar.gz`
* `build/<mode>/dist/tar/scylla-package.tar.gz`
* `build/<mode>/dist/tar/scylla-python3-package.tar.gz`
* `build/<mode>/dist/tar/scylla-jmx-package.tar.gz`
* `build/<mode>/dist/tar/scylla-tools-package.tar.gz`

**.rpms:**

* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-*.rpm`
* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-conf-*.rpm`
* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-debuginfo-*.rpm`
* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-kernel-conf-*.rpm`
* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-node-exporter-*.rpm`
* `build/dist/<mode>/redhat/RPMS/x86_64/scylla-server-*.rpm`
* `tools/python3/build/redhat/RPMS/x86_64/scylla-python3-*.rpm`

**.debs:**

* `build/dist/<mode>/debian/scylla-conf_*.deb`
* `build/dist/<mode>/debian/scylla_*.deb`
* `build/dist/<mode>/debian/scylla-server_*.deb`
* `build/dist/<mode>/debian/scylla-kernel-conf_*.deb`
* `build/dist/<mode>/debian/scylla-node-exporter_*.deb`
* `build/dist/<mode>/debian/scylla-server-dbg_*.deb`
* `tools/python3/build/debian/scylla-python3_*.deb`
