Tag: systemd

  • Autostart icecast using systemd

    To autostart icecast using systemd, create a unit file

    vi /etc/systemd/system/icecast.service

    Add following content

    [Unit]
Description=Icecast Network Audio Streaming Server
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/icecast -c /etc/icecast/icecast.xml
ExecReload=/bin/kill -HUP $MAINPID
User=icecast
Group=icecast
WorkingDirectory=/home/icecast/

[Install]
WantedBy=multi-user.target

    Enable icecast to start on boot with

    systemctl enable icecast

    To start/stop/restart icecast, use

    systemctl start icecast
systemctl stop icecast
systemctl restart icecast

  • Systemd Journal

    Systemd have its own loggin system called Systemd Journal. It keep track of logs for each service.

    To see log for a service, run

    journalctl -u SERVICE_NAME

    Example

    root@ocp-serverok-in:~# journalctl -u myapp
-- Logs begin at Wed 2020-05-27 06:43:34 UTC, end at Fri 2020-06-26 09:33:19 UTC. --
Jun 26 08:53:59 ocp-serverok-in systemd[1]: Started Sample web server.
Jun 26 08:53:59 ocp-serverok-in cat[36147]: Starting web server
root@ocp-serverok-in:~#

  • Start an application using systemd

    systemd is used to start applications on linux systems.

    In this post, we will create an application and run start it on boot using systemd.

    Lets create our sample application.

    mkdir /root/myapp/
vi /root/myapp/web.sh

    Add following content to the file and save.

    #!/bin/bash

echo "Starting web server" | systemd-cat -p info

cd /root/myapp
python3 -m http.server 80

    You can start the application by running following command on terminal

    bash /root/myapp/web.sh

    this will run a simple web server on port 80. If you already have a web server running on port 80, change the port to another.

    To stop web server, type CTRL+C.

    Create Systemd service file

    To manage this application using systemd, we need to create a service file.

    vi /etc/systemd/system/myapp.service

    Add

    [Unit]
Description=Sample web server

[Service]
Type=simple
ExecStart=/bin/bash /root/myapp/web.sh

[Install]
WantedBy=multi-user.target

    systemd service file

    Managing Systemd service

    First you need to enable the service with

    systemctl enable myapp

    To start the service, run

    systemctl start myapp

    To stop the service, run

    systemctl stop myapp

    To see status of the service, run

    systemctl status myapp