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Runing the CommandExecutor from Shell

You can also run the CommandExecutor as a module from python

python -m Matrix.driver.executor

Listing available commands

python -m Matrix.driver.executor -l

Running a command

Running the mta command for 200 seconds

python -m Matrix.driver.executor -c mta -d 200

Running the meteo command for 20 seconds

python -m Matrix.driver.executor -c meteo -d 20

Start with Scheduler

Start the scheduler: (see schedule.json)

python -m Matrix.driver.executor --scheduler

Simple Command Line wrapper

The CommandExecutor can be used as a CLI.

Once the setup is completed, you can use the ppnctl script:

./ppnctl ls

=> will list available commands

./ppnctl run news 200

=> will execute the news command for 200s

IPC

Why IPC is needed

When driving a real LED Matrix, the code needs to be started as root, this is a constraint from the rpi-rgb-led-matrix lib.

As indicated in the documentation the lib drops privilege by default, but it result in a lot of strange file related issues: unable to load files, unable to load python module ...

As a result, the CommandExector needs to run as root the Matris with drop_privileges = False.

Because the API Server should not run as root, the CommandExecutor can be used as a IPC Server. The API Server uses the IPC Client to communicate with the CommandExcutor via IPC. The CommandExcutor can run as root, whereas the client can run as a low privilege user.

REST API(low_privilege) => IPC_Client(low_privilege) => IPC_Server(root) => rpi-rgb-led-matrix

Because the IPC communication relies on Linux local Socket, this should be safe.

Laptop mode vs Pi/Matrix mode

Running the CommandExecutor as root is only needed when running on the Pi using GPIO and rpi-rgb-led-matrix to drive the Matrix.

When using on a laptop using the RGBMatrixEmulator, running as root is not useful, so you do not need to run as root, so the IPC part can be skipped.

IPC is available in both modes.in order to facilitate testing.

Running in IPC mode

To run in IPC mode:

Starting CommandExecuter as a IPC Server

When started with --listen the CommandExecutor will start a socket server

python -m Matrix.driver.executor --listen --scheduler

Interactive CommandLine IPC Client

Matrix.driver.ipc.client contains a RemoteCLI class that acts as an interactive CLI using the IPC client to control the CommandExecutor through the IPC Server.

python -m Matrix.driver.ipc.client --remotecli

Available CLI commands:

ls commands : list commands registered in the CmdExecutor

ls schedules : list schedules / playlists registered in the CmdExecutor

command <command_name> : retrieve definition of command <command_name>

schedule <schedule_name> : retrieve definition of Schedule <schedule_name>

commands : retrieve definition of all commands

run <command_name> arg1 arg2 arg3: run command <command_name> using positional arguments

set_schedule <schedule_name> <json>: update or create the schedule <schedule_name> with the provided

save_schedule: persist the schedule definitions

exit: disconnect and exit gracefully

Runing in Pi mode / rpi-rgb-led-matrix mode

When running the CommandExecutor as root using sudo, we need to reestablish the python venv for the root user.

Execute a command as root

sudo -E scripts/run_cmd_as_root.sh <command_name> <duration>

Start the Command Server as root is listen mode

sudo -E scripts/start_cmd_server.sh