README.md

# Fuchsia samples using the Fuchsia SDK with Rust

**Note: Rust is not yet supported in the Fuchsia SDK.**

This repository contains instructions and source code to build, package and run
an example rust component which runs on Fuchsia using only the Fuchsia SDK.

## Requirements

1. Make sure this repository has the required submodules:

   ```
   git submodule update --recursive --init
   ```

2. Run the bootstrap script that downloads the appropriate Bazel binary:

   ```
   scripts/bootstrap.sh
   ```

3. Ensure that there are Fuchsia SSH keys in your host machine. You will need
   them for running the Fuchsia emulator.

   ```
    [[ -f "${HOME}/.ssh/fuchsia_ed25519" ]] || ssh-keygen -P "" -t ed25519 -f "${HOME}/.ssh/fuchsia_ed25519" -C "${USER}@$(hostname -f) Shared SSH Key for Fuchsia"

    [[ -f "${HOME}/.ssh/fuchsia_authorized_keys" ]] || ssh-keygen -y -f "${HOME}/.ssh/fuchsia_ed25519" > "${HOME}/.ssh/fuchsia_authorized_keys"
   ```

## Build, run and test the samples

Now the repository is ready to build the samples.

1. Fetch the system images

   ```
   tools/ffx product-bundle get workstation_eng.qemu-x64 --repository workstation-repo
   ```

   > Note: if the product-bundle command above fails with an error message that
   > states that there are multiple product bundles with the same name, you can either specify
   > the fully qualified URL as printed in the error message that corresponds to
   > your SDK version (use `tools/ffx sdk version` if needed), or you can wipe out
   > old and unused product bundles in the pbms storage, which should be located
   > in ~/.local/share/Fuchsia/ffx/pbms on Linux, or ~/Library/Fuchsia/ffx/pbms
   > on MacOS.

2. Start the emulator

   ```
   tools/ffx emu start workstation_eng.qemu-x64 --headless
   ```

3. The product bundle comes with on-demand packages in a separate repository.
   Use the following command to register it with the emulator:

   ```
   tools/ffx target repository register -r workstation-repo --alias fuchsia.com
   ```

4. watch the device log in a separate window

   ```
   tools/ffx log --filter core/ffx-laboratory:hello_rust
   ```

5. Run the hello world component

   ```
   tools/bazel run //src/hello_rust:pkg.component
   ```

   Watch in the log that the message "Hello, Rust!" is printed. Modify the
   Hello world message in [src/hello_rust/src/main.rs](src/hello_rust/src/main.rs), repeat this step
   and see that the log shows the new message.

<!--
   TODO: add tests
1. Run unit tests for samples

   ```
   tools/bazel test --config=fuchsia_x64 src/hello_world:test_pkg
   tools/bazel test --config=fuchsia_x64 src/echo:test_pkg
   ```
-->