Commander

Microservice for executing commands via API requests

Introduction

Commander acts like a scripting interface to any Linux computer. The service is able to receive commands via its built-in API server in order to execute them. The main purpose of this software is to be used alongside Smarthome-server in order to allow Homescript to control remote computers.

Warning: Even though access requires a token, running commander comes at your own risk because it opens up a potent entrance for possible attackers to use.

API Usage

To execute an arbitrary command, issue a POST request using following parameters.

Key	Value
Method	POST
URL	http://ip/exec
Header1	Token: your_token
Header2	Content-Type: application/json
Body	{ command: "ls"} (as JSON)

Usage from Smarthome via Homescript

Note: This example uses Smarthome-server v0.0.47 (which uses Homescript v0.15.1).

To test this code, execute your_id using the command argument with your command as its value.

# Calling `your_id` from outside
exec(
    'your_id',
    pair('command', "ls")
)

# This is the beginning of `your_id`
http(
    'http://computer.box/exec',
    'POST',
    concat('{', '"command":"', getArg('command'), '"}'),
    pair('Content-Type', 'application/json'),
    pair('Token', 'test'),
)

Installation

Manual installation

Cloning

git clone git@github.com:smarthome-go/commander
cd commander

Installation

make install

Installing a Systemd Service (Optional)

sudo cp commander@.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl start commander@$USER

Additional configuration

Note: Modifying the .service file is not recommended (except for environment variables)

When using Systemd, the service is configured using environment variables. The most important configuration parameters are explained below.

Parameter	Explanation
ROCKET_PORT	The port on which commander listens on
COMMANDER_TOKEN	Unencrypted user authentication token

Representation in the .service file (which is located at /etc/systemd/system/commander@.service)

# Environment variables for the service
Environment=ROCKET_PORT=7070
Environment=COMMANDER_TOKEN=test

In some cases, you might want to start applications with a GUI or which depend on audio. On those occasions, the command might fail due to missing environment variables. You can feel free to include the missing variables under the # Put user environment variables here marker. When you don't want to take on the hassle of figuring our which missing environment variable is causing the issue, you can inclue all your current variables in the file. The command for listing your environment variables on Unix is env. But don't forget to run sudo systemctl daemon-reload after writing modifications to the service file.

Note: It is not recommended to include all of your environment variables in the service file.

Arch Linux

If using Arch Linux, the most convenient way of installing commander is via the AUR (Arch Linux User Repository). For this, an AUR helper like paru or yay is used.

Note: This method automatically installs a Systemd service, however it is not enabled by default.

paru -S commander