IT-OS-Admin-Linux
Contents
Source
- Commands: https://ss64.com/bash/
- src: https://docs.fedoraproject.org/en-US/docs/
- RHEL-Trainig: https://www.redhat.com/en/services/training/rh024-red-hat-linux-technical-overview
- src: https://www.howtoforge.com/
Setting User
sudo adduser –G [GROUP-ID] [USER-ID] # Add a new Group & User sudo deluser [USER-ID] # Delete User sudo remove [USER-ID] # Remove User ... echo "USER-ID ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers usermod -aG sudo [USER-ID] # Add User to Sudo-Group sudo visudo # Add “USER-ID ALL=(ALL:ALL) ALL” id ... su [USER-ID] # Change User in current Folder su - [USER-ID] # Change User in User Home-Folder sudo bash # Login as root sudo -i # Login as root sudo -i –u [USER-ID] # Login in account user passwd [USER-ID] # Change User Password gpasswd -a user-ID group-ID #
SSH
$ sudo dnf install openssh-client $ sudo dnf install openssh-server $ sudo systemctl restart sshd.service $ sudo systemctl enable sshd.service
# Key-Typs: RSA algorithm and DSA algorithm. $ ~/.ssh/id_rsa.pvt # The file contains the RSA private key. $ ~/.ssh/id_rsa.pub # The file contains the RSA public key. $ ~/.ssh/authorized_keys # The file contains the keys that can be used for logging into system. ... sudo nano /etc/ssh/ssh_config sudo nano /etc/ssh/sshd_config ------------------------------ RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile %h/.ssh/authorized_keys PasswordAuthentication no # Yes: Can login with Password; No: Can’t login with Password ------------------------------ /etc/init.d/ssh restart
$ ssh-keygen -t rsa -f ~/.ssh/$FILENAME_KEY -C $USERNAME # Generate prv and pub Key $ ssh -i $PATH_PRIVATE_KEY $USERNAME@$IP_ADDRESS # Login server with prv-key ... $ ssh-copy-id –i $PATH_PUBLIC_KEY $USERNAME@IP_ADDRESS # Copy Pub-Key to server $ cat ~/.ssh/id_rsa.pub | ssh user@hostname "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys" $ ssh user@hostname "echo `cat ~/.ssh/id_rsa.pub` >> ~/.ssh/authorized_keys"
chmod
- d:Directory, r:Read, w:Write, x:Execute
- u:User, g:Group, o:Others, a:everyone:[ugo]
- 4=read, 2=write, 1=execute, 0=no promission #<<-- Combination of the Digits
$ chmod uga+rwx -R $FILE_NAME # Give permission (rwx) for (user, group, everyone) $ chmod u=rwx,g=rwx,o=rwx $FILE_NAME $ chmod 755 $FILE_NAME
Setting Firewall
Service
$ sudo systemctl disable firewalld $ sudo systemctl stop firewalld $ sudo systemctl disable NetworkManager $ sudo systemctl stop NetworkManager $ sudo systemctl enable network $ sudo systemctl start network
Zone
sudo firewall-cmd --get-zones sudo firewall-cmd --get-active-zones sudo firewall-cmd --get-default-zone sudo firewall-cmd --get-services sudo firewall-cmd --list-all sudo firewall-cmd --list-ports
Zone-home
sudo firewall-cmd --zone=home --list-all sudo firewall-cmd --zone=home --list-ports sudo firewall-cmd --zone=home --list-services
Setting
sudo firewall-cmd --set-default-zone=home sudo firewall-cmd --zone=home --change-interface=eth0 sudo firewall-cmd --zone=home --add-service=http sudo firewall-cmd --zone=home --add-port=80/tcp --permanent
New Zone "boxblue"
sudo firewall-cmd --permanent --new-zone=boxblue sudo firewall-cmd --permanent --zone=boxblue --add-service=ssh sudo firewall-cmd --permanent --zone=boxblue --add-service=http sudo firewall-cmd --permanent --zone=boxblue --add-service=https sudo firewall-cmd --permanent --zone=boxblue --add-port=80/tcp sudo firewall-cmd --permanent --zone=boxblue --add-port=22/tcp sudo firewall-cmd --permanent --zone=boxblue --change-interface=wlp0s19f2u1 sudo firewall-cmd --permanent --set-default-zone=boxblue
Update
sudo firewall-cmd --reload sudo systemctl restart network sudo systemctl reload firewalld
Vim
Source: https://vim.rtorr.com/
Esc Exit the current mode. i Enter "Insert mode" for inserting text. v Enter "Visual mode" for character. V Enter "Visual mode" for line. : Enter "Command mode". ... h Move Left j Move Down k Move Up l Move Right ... ggVG Select hole text ... u Undo the last operation. d Delete or Cut selected item. y Copy line. p Paste storage buffer after the cursor. ... :q Quit Vim. :q! Quit Vim without saving the changes. :w Save the file :wq Save the file and quit Vim. :w $FILE_NAME Save the file with the filename "yx".
Setting User
sudo adduser –G [GROUP-ID] [USER-ID] # Add a new Group & User sudo deluser [USER-ID] # Delete User sudo remove [USER-ID] # Remove User ... echo "USER-ID ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers usermod -aG sudo [USER-ID] # Add User to Sudo-Group sudo visudo # Add “USER-ID ALL=(ALL:ALL) ALL” id ... su [USER-ID] # Change User in current Folder su - [USER-ID] # Change User in User Home-Folder sudo bash # Login as root sudo -i # Login as root sudo -i –u [USER-ID] # Login in account user passwd [USER-ID] # Change User Password gpasswd -a user-ID group-ID #
DNF: Package Manager (fedora)
DNF: Dandified YUM
... rpm –i filename.rpm ... dnf --version dnf --enablerepo=epel ... sudo ls /etc/yum.repos.d/ sudo dnf repolist sudo dnf repoinfo sudo dnf config-manager --add-repo $REPO_NAME sudo dnf config-manager --set-enabled $REPO_NAME sudo dnf config-manager --set-disabled $REPO_NAME ... sudo dnf copr [enable|disable|remove|list|search] <parameters> ... dnf list installed dnf list available dnf provides /bin/bash dnf search dnf info nano dnf install nano dnf update nano dnf upgrade dnf check-update dnf remove nano dnf autoremove dnf clean all ... dnf grouplist dnf groupinstall 'Educational Software' dnf groupupdate 'Educational Software' dnf groupremove 'Educational Software' ... dnf distro-sync dnf reinstall nano dnf downgrade acpid
Samba
/etc/samba/smb.conf
