Getting started with systemd
This document describes the simple intro of
systemd, sample systemd service file for your aah application and steps to accomplish it.
systemd is an init system that provides many powerful features for starting, stopping, reload configuration and managing processes. Refer to systemd man page.
systemd consists of two main concepts:
- A unit is a configuration file that describes the properties of the process that you’d like to run.
- A target is a grouping mechanism that allows systemd to start up groups of processes at the same time. This happens at every boot as processes are started at different run levels.
Table of Contents
systemd service file
aahframework.org website service file. aah application build archive extracted at location
[Unit] Description=aahframework.org After=network.target [Service] EnvironmentFile=/home/aah/env_values User=aah Group=aah Type=forking ExecStart=/home/aah/website/aah.sh start ExecStop=/home/aah/website/aah.sh stop Restart=on-failure [Install] WantedBy=multi-user.target
Steps to Configure and Enable
- Step 1: create a service file at
/etc/systemd/system/aahwebsite.servicewith above reference for your application.
- Step 2: we are gonna reload it
sudo systemctl daemon-reload.
- Step 3: to enable
sudo systemctl enable aahwebsite.service.
- Step 4: congrats, you have successfully created service file.
How to Start, Stop, Restart and Status
We have successfully created a service file, let’s see how to run it. Don’t forget to replace your service filename with below example commands.
Start your application
sudo systemctl start aahwebsite.service # OR sudo systemctl start aahwebsite # OR sudo service aahwebsite start
Stop your application
sudo systemctl stop aahwebsite.service # OR sudo systemctl stop aahwebsite # OR sudo service aahwebsite stop
Restart your application
sudo systemctl restart aahwebsite.service # OR sudo systemctl restart aahwebsite # OR sudo service aahwebsite restart
Status of your application
sudo systemctl status aahwebsite.service # OR sudo systemctl status aahwebsite # OR sudo service aahwebsite status
You will get similar output:
● aahwebsite.service - aahframework.org Loaded: loaded (/etc/systemd/system/aahwebsite.service; enabled; vendor preset: enabled) Active: active (running) since Fri 2017-09-22 17:05:20 PDT; 6s ago Process: 16623 ExecStart=/home/aah/website/aah.sh start (code=exited, status=0/SUCCESS) Main PID: 16629 (aahwebsite) Tasks: 6 Memory: 8.4M CPU: 748ms CGroup: /system.slice/aahwebsite.service └─16629 /home/aah/website/bin/aahwebsite -profile=prod Sep 22 17:05:20 cn01-sfo.aahframework.org systemd: Starting aahframework.org... Sep 22 17:05:20 cn01-sfo.aahframework.org aah.sh: aahwebsite started. Sep 22 17:05:20 cn01-sfo.aahframework.org systemd: Started aahframework.org.