# Systemd Services

# What is a service
A service is a program or script that runs in the background and is managed by the system. Services are started at boot time and run until the system is shut down. Services can be started, stopped, and restarted by the system administrator.

# How to manage services on systemD

## Starting a service
To start a service, use the `systemctl start` command followed by the service name. For example, to start the `apache2` service, use the following command:

```bash
sudo systemctl start apache2
```

## Stopping a service
To stop a service, use the `systemctl stop` command followed by the service name. For example, to stop the `apache2` service, use the following command:

```bash
sudo systemctl stop apache2
```

## Restarting a service
To restart a service, use the `systemctl restart` command followed by the service name. For example, to restart the `apache2` service, use the following command:

```bash
sudo systemctl restart apache2
```

## Enabling a service
To enable a service to start at boot time, use the `systemctl enable` command followed by the service name. For example, to enable the `apache2` service, use the following command:

```bash
sudo systemctl enable apache2
```

## Creating a new service
To create a new service, you need to create a new service file in the `/etc/systemd/system/` directory. The service file should have a `.service` extension and contain the following sections:

### Example service file:

```bash
[Unit]
Description=FlaskApp #description of the service
After=network.target #start the service after the network is up

[Service]
User=ishak #start the service as a specific user
WorkingDirectory=/home/ishak/rooziinuubii79/src/Python/flask/web/ #working directory of the service
ExecStart=/usr/bin/gunicorn -w 3 -b 127.0.0.1:5000 app:app #command to start the service
```