linux – Page 6

Set Date and Time From a Command Prompt in Linux

November 28, 2022

date

date --set="2 OCT 2006 18:00:00"

References
https://www.cyberciti.biz/faq/howto-set-date-time-from-linux-command-prompt/

Install .NET 7 on Ubuntu 22.04 using Microsoft package feed

November 23, 2022

wget https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

sudo apt-get update && \
  sudo apt-get install -y dotnet-sdk-7.0

References
https://learn.microsoft.com/en-us/dotnet/core/install/linux-ubuntu#2204-microsoft-package-feed

Install .NET 7 on Ubuntu using Snap

November 23, 2022

sudo snap install dotnet-sdk --classic --channel=7.0

sudo snap alias dotnet-sdk.dotnet dotnet

You can edit your shell profile to permanently add the commands.

Bash Shell: ~/.bash_profile, ~/.bashrc

export DOTNET_ROOT=/snap/dotnet-sdk/current

References
https://learn.microsoft.com/en-us/dotnet/core/install/linux-snap
https://stackoverflow.com/questions/68519558/how-to-fix-segmentation-fault-core-dumped-when-creating-new-dotnet-project

Restart network on Ubuntu 22.04

November 2, 2022

sudo ip link set enp0s3 down
sudo ip link set enp0s3 up

sudo nmcli networking off
sudo nmcli networking on

References
https://linuxconfig.org/how-to-restart-network-on-ubuntu-22-04-lts-jammy-jellyfish

Allow GUI root login on Ubuntu 22.04

November 1, 2022

sudo passwd

sudo nano /etc/gdm3/custom.conf

Inside the GDM configuration file, we need to add the AllowRoot=true line. After you have made this change, you can save and exit the file.

AllowRoot=true

sudo nano /etc/pam.d/gdm-password

Inside of the PAM authentication daemon file, comment out the following line, which denies root access to the graphical user interface, with a pound sign #. You can save your changes and exit this file when done.

auth   required        pam_succeed_if.so user != root quiet_success

reboot

References
https://linuxconfig.org/how-to-allow-gui-root-login-on-ubuntu-22-04-jammy-jellyfish-linux

Configure Static IP Address On Ubuntu 22.04

November 1, 2022

nano /etc/netplan/00-installer-config.yam

network:
    ethernets:
        enp0s3:
            addresses:
            - 10.66.10.7/16
            dhcp4: false
            routes:
              - to: default
                via: 10.66.10.1
            nameservers:
                addresses:
                - 8.8.8.8
                - 8.8.4.4
                search:
                - workgroup
    version: 2

sudo netplan try

sudo netplan apply

References
https://technologyrss.com/how-to-configure-static-ip-address-on-ubuntu-22-04/

Disable IPv6 on UFW on Linux

October 30, 2022

sudo nano /etc/default/ufw

Change the line that says: IPV6=yes to IPV6=no then restart the ufw service. You can even run sudo ufw reload if the ufw instance is already enabled.

References
https://serverfault.com/questions/809643/how-do-i-use-ufw-to-open-ports-on-ipv4-only

Install .NET Core SDK in Manjaro Linux

October 28, 2022

sudo pacman -S dotnet-sdk

sudo pacman -S aspnet-runtime

Then, you’ll need to create /etc/profile.d/dotnet.sh and add the following:

export DOTNET_ROOT=/usr/share/dotnet
export MSBuildSDKsPath=$DOTNET_ROOT/sdk/$(${DOTNET_ROOT}/dotnet --version)/Sdks
export PATH=${PATH}:${DOTNET_ROOT}

dotnet --list-sdks

To use the extra tools, such as dotnet ef, you will want to add a line to your .bashrc file.

nano ~/.bashrc

And add the following at the end:

export PATH="$PATH:/home/jeremy/.dotnet/tools"

source ~/.bashrc

References
https://www.jeremymorgan.com/tutorials/linux/how-to-install-dotnet-manjaro/
https://github.com/dotnet/core/issues/7087

Create a Linux Swap File

October 19, 2022

sudo fallocate -l 1G /swapfile

sudo chmod 600 /swapfile

sudo mkswap /swapfile

sudo swapon /swapfile

To make the change permanent open the /etc/fstab file and append the following line:

/swapfile swap swap defaults 0 0

sudo swapon --show

sudo free -h

References
https://linuxize.com/post/create-a-linux-swap-file/

Installing dnscrypt-proxy on Linux

October 19, 2022

Get a root shell

sudo -s

check what else is possibly already listening to port 53

ss -lp 'sport = :domain'

systemctl stop systemd-resolved
systemctl disable systemd-resolved

ss -lp 'sport = :domain'

Download and run dnscrypt-proxy

Download dnscrypt-proxy here: dnscrypt-proxy binaries.

cp example-dnscrypt-proxy.toml dnscrypt-proxy.toml

./dnscrypt-proxy

Change the system DNS settings

apt-get remove resolvconf

cp /etc/resolv.conf /etc/resolv.conf.backup

rm -f /etc/resolv.conf

And create a new /etc/resolv.conf file with the following content:

nameserver 127.0.0.1
options edns0

Install the proxy as a system service

./dnscrypt-proxy -service install

./dnscrypt-proxy -service start

./dnscrypt-proxy -service stop

./dnscrypt-proxy -service restart

./dnscrypt-proxy -service uninstall

Want to check that DNS resolution works?

./dnscrypt-proxy -resolve example.com

Connect to 1.1.1.1 using DoH clients

Add cloudflare and cloudflare-ipv6 to the server list in dnscrypt-proxy.toml:

server_names = ['cloudflare', 'cloudflare-ipv6']

References
https://github.com/DNSCrypt/dnscrypt-proxy/wiki/Installation-linux
https://developers.cloudflare.com/1.1.1.1/encryption/dns-over-https/dns-over-https-client/