servicehandler is an orchestrator for systemd services, distributed as a Python package. It provides abstraction for services and implements helper methods, wrapping the systemctl command

Using the package does not require root permissions, as the user service manager is used (with unit files in /usr/lib/systemd/user/)

Description

A service (aka daemon) is defined by its unit file (e.g. /usr/lib/systemd/user/my-service.service):

[Unit]
Description=My service

[Service]
ExecStart=/usr/bin/python3 /home/user/service_script/main.py
Environment=PATH=/bin:/usr/bin:/usr/local/bin
WorkingDirectory=/home/user/service_script/

[Install]
WantedBy=multi-user.target

Usage

Create a ServiceHandler object

import servicehandler as sh

my_service = sh.ServiceHandler('MyService','my-service.service')

Control the state of a service

# Check current state
my_service.state()
<ServiceState.STOPPED: 2>

# Start the service
> my_service.start()
MyService changed state to ServiceState.RUNNING
<Response.OK: 1>

# Try to start again the service
> my_service.start()
<Response.ALREADY: 2>

# Terminate the service
> my_service.stop()
MyService changed state to ServiceState.STOPPED
<Response.OK: 1>

# Kill the service
# In this specific case, the unit file was configured with restart=on-failure (automatic restart)
> my_service.kill()
<Response.OK: 1>

Control the enablement_state of a service (whether it automatically starts on system startup)

# Check current enablement_state
> my_service.enablement_state()
<ServiceEnablementState.DISABLED: 2>

# Enable the service
> my_service.enable()
Created symlink /home/user/.config/systemd/user/multi-user.target.wants/my_service.service → /usr/lib/systemd/user/my_service.service.
MyService changed enablement state to ServiceEnablementState.ENABLED
<Response.OK: 1>

# Disable the service
> my_service.disable()
Removed /home/user/.config/systemd/user/multi-user.target.wants/my_service.service.
MyService changed enablement state to ServiceEnablementState.DISABLED
<Response.OK: 1>

Iterate over different services and perform batch operations

import servicehandler as sh

service_A = sh.ServiceHandler('ServiceA','A-config-file.service')
service_B = sh.ServiceHandler('ServiceB','B-config-file.service')
service_C = sh.ServiceHandler('ServiceC','C-config-file.service')

services = [ServiceA, ServiceB, ServiceC]

# Iterate over the services easily
for srv in services:
    if srv.state() == sh.ServiceStatus.STOPPED:
        srv.restart()
    print(srv.state())

Installation

Install using pip

servicehandler is available on PyPI and it can be installed using pip:

pip install servicehandler

Build from source

As an alternative, it's possible to build and install the package from source:

git clone https://github.com/albertosantagostino/systemd-servicehandler
cd systemd-servicehandler
python3 setup.py install

Development history and use cases

Manage multiple services from a single entry-point

This package was developed while working on a Telegram bot overlord manager, created to handle other bots (and services) running on the same platform, providing a single point of access to the user

In the scenario multiple bots run on a headless Raspberry Pi Zero. In order to start them when needed, check their logs and interact with them without opening an SSH session every time, a brand new all-powerful Telegram bot was created, weaponized with this newly created package

License

The package is distributed under the MIT License