session_manager

Reviewed on: 2021-10-01

session_manager is the component that runs and manages sessions. For more information on what sessions are and what roles they play in products built on Fuchsia, see Session Framework

Building

Add the session_manager component to builds by including --with-base //src/session/bin/session_manager in the fx set invocation followed by rebuilding and re-paving the device.

Product configurations built on Session Framework (such as fx set workstation_eng.x64) include //src/session/bin/session_manager by default.

Running

session_manager is launched in one of two ways: manually or automatically on system boot.

In general, running manually is useful during development, while running on boot is desirable for a production configuration.

Running manually

Use the [ffx session]((/docs/development/tools/ffx/getting-started.md) tool to launch a specific session:

ffx session launch fuchsia-pkg://fuchsia.com/your_session#meta/your_session.cm

Launching a session on boot

session_manager attempts to launch a session on boot based on the contents of its session_url configuration parameter.

To boot into a session, include session_manager and the session component in the base package set and assign the URL of the session component to the product configuration:

fx set core.qemu-x64 \
  --with-base //src/session/bin/session_manager \
  --with-base //path/to/your_session \
  --args=product_config.session_url="fuchsia-pkg://fuchsia.com/your_package#meta/your_session.cm"

This can also be configured directly in a product's definition *.gni files or via fx args.

Re-build, re-pave, and restart your device and it will boot into session_manager and launch your session.

Testing

Unit tests for session_manager are included in the session_manager_tests package, and integration tests are included in the session_manager_integration_tests package.

Both can be included in your build by adding --with //src/session:tests to your fx set.

fx test session_manager_tests
fx test session_manager_integration_tests

Source layout

The entry point for session_manager is in src/main.rs with implementation details in other files within src/.

Unit tests are co-located with the code, while integration tests are in //src/session/tests.