Tag: linux

Use a Self-Signed SSL Certificate for Nginx Server

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/nginx-selfsigned.key -out /etc/ssl/certs/nginx-selfsigned.crt

Modify Your Nginx Server Block:

server {
    listen 443 ssl;
    server_name your_domain.com;

    ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
    ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;

    location / {
        # Your proxy or root configurations
    }
}

sudo nginx -t
sudo systemctl reload nginx

 

Set Battery Charge Limit in Fedora

sudo nano /etc/systemd/system/battery-charge-threshold.service

[Unit]
Description=Set battery charge threshold to 60%
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/bin/bash -c 'echo 60 > /sys/class/power_supply/BAT0/charge_control_end_threshold'
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable --now battery-charge-threshold.service

 

Disable systemd-networkd-wait-online.service in Ubuntu Server

In Ubuntu Server, the systemd-networkd-wait-online.service is responsible for waiting until the network is fully online before allowing the boot process to continue. This service can sometimes cause delays during the boot process if the network configuration takes a long time to initialize.

1. Disable the Service

To completely disable the systemd-networkd-wait-online.service, run the following command:

sudo systemctl disable systemd-networkd-wait-online.service

This will prevent the service from starting at boot time.

2. Mask the Service (Optional)

If you want to ensure that the service cannot be started manually or automatically by any other service, you can mask it:

sudo systemctl mask systemd-networkd-wait-online.service

Masking creates a symbolic link to /dev/null, making it impossible for the service to start unless explicitly unmasked.

Install Syncthing on Ubuntu 24.04

# Add the release PGP keys:
sudo mkdir -p /etc/apt/keyrings
sudo curl -L -o /etc/apt/keyrings/syncthing-archive-keyring.gpg https://syncthing.net/release-key.gpg
# Add the "stable" channel to your APT sources:
echo "deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] https://apt.syncthing.net/ syncthing stable" | sudo tee /etc/apt/sources.list.d/syncthing.list
# Update and install syncthing:
sudo apt-get update
sudo apt-get install syncthing

Syncthing can be run as a service so that it starts automatically on boot.

  1. Enable the Syncthing service : By default, Syncthing installs a systemd service for the user syncthing. You can enable it to start on boot. 
    sudo systemctl enable syncthing@<username>.service

    Replace <username> with the username of the user who will run Syncthing. For example, if your username is ubuntu, the command would be:

    sudo systemctl enable syncthing@ubuntu.service
  2. Start the Syncthing service : Once enabled, start the Syncthing service. 
    sudo systemctl start syncthing@<username>.service

By default, Syncthing runs on localhost and listens on port 8384.

References
https://apt.syncthing.net/

Change NTP server on a Linux system to a local NTP server

  1. Open the Chrony configuration file: 
    sudo nano /etc/chrony/chrony.conf
  2. Find the existing NTP servers and comment them out by adding a # at the beginning of the line, or remove them if you prefer: 
    # server 0.pool.ntp.org iburst
# server 1.pool.ntp.org iburst
  3. Add your local NTP server:

    Replace local_ntp_server_ip with the IP address or hostname of your local NTP server:

    server local_ntp_server_ip iburst
  4. Save and exit the editor (for nano, press CTRL+X, then Y, and Enter).
  5. Restart the Chrony service to apply changes: 
    sudo systemctl restart chronyd
  6. Verify the synchronization:

    After a few minutes, you can check the NTP synchronization status:

    chronyc sources

     

Manually set the time on an Ubuntu server

1. Check the current time

Before setting the time, check the current system time by running:

timedatectl

This will display information about your system’s time and time zone.

2. Set the time manually

To set the time manually, use the timedatectl command in the following format:

sudo timedatectl set-time "YYYY-MM-DD HH:MM:SS"

For example, to set the date and time to October 12, 2024, 19:30:00, you would run:

sudo timedatectl set-time "2024-10-12 19:30:00"

3. Disable automatic time synchronization (if needed)

If your server is using NTP (Network Time Protocol) for automatic time synchronization, you may need to disable it before setting the time manually. To do this, run:

sudo timedatectl set-ntp off

4. Verify the new time

After setting the time, you can verify it with:

timedatectl

This will show the updated time and any other related settings.

Update Kernel arguments for better performance in Ubuntu 24.04

Here’s how you can apply these kernel parameters in Ubuntu 24.04:

  1. Edit GRUB Configuration File:

    Open the GRUB configuration file in a text editor. For example, you can use nano:

    sudo nano /etc/default/grub
  2. Add Kernel Parameters:

    Find the line that starts with GRUB_CMDLINE_LINUX_DEFAULT and add your parameters to the list. It should look something like this:

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mitigations=off mem_sleep_default=s2idle nvidia-drm.modeset=1"

    Ensure that all parameters are enclosed within the same set of quotes.

  3. Update GRUB:

    After saving the changes, you need to update the GRUB configuration:

    sudo update-grub
  4. Reboot:

    Finally, reboot your system to apply the changes:

    sudo reboot

This will apply the desired kernel parameters on all boot entries.