Skip to main content

Linux notes

Change SWAP size

  1. Turn off all running swap processes: swapoff -a
  2. Resize swap fallocate -l 1G /swapfile (change 1G to the gigabyte size you want it to be)
  3. CHMOD swap: chmod 600 /swapfile
  4. Make file usable as swap mkswap /swapfile
  5. Active the swap file swapon /swapfile

To verify your swap size run the following command and you will see the swap size: free -m

Copy key to remote host

scp -i ~/.ssh/id_rsa user@10.0.0.1:.ssh/id_rsa

Change user password

passwd username

Login via SSH with password

nano /etc/ssh/sshd_config
PasswordAuthentication yes/no
AllowUsers jenkins
systemctl restart sshd

Add host to known hosts

ssh-keyscan github.com >> ~/.ssh/known_hosts

Show where the command is located and add to PATH

which molecule
echo $PATH
export PATH=$PATH:/path/to/molecule

Add user to sudoers

nano /etc/sudoers

Add ssh key for system

chmod 600 ~/.ssh/id_rsa
ssh-add ~/.ssh/id_rsa

Add admin for system

useradd -m -s /bin/bash admin
passwd admin
usermod -aG wheel admin
visudo

Install FTP

apt update
apt install vsftpd
systemctl start vsftpd
systemctl enable vsftpd
useradd -m testuser
passwd testuser
ufw allow 20/tcp
ufw allow 21/tcp
mkdir /srv/ftp/new_location
usermod -d /srv/ftp/new_location ftp
systemctl restart vsftpd.service
nano /etc/vsftpd.conf
/etc/vsftpd.conf
write_enable=YES
systemctl restart vsftpd.service
chroot_local_user=YES
chroot_list_file=/etc/vsftpd.chroot_list