Server administration
General helpbase for server administration stuff

User commands
Linux commands for handling users and roles: 
 
 adduser name   //Adds a new user interactivly (creates a default shell and home directory) 
 deluser name   //Removes a user 
 deluser --remove-home name //Removes a user and also deletes their home directory 
 usermod -aG group name   //Give a user a role, such as sudo 
 passwd name   //Set the password for a given user, or if no user is supplied for the current user 
 groups   //List out all groups on the system 
 users  //List out all users on the system

SSH Configuration
The ssh configuration file is stored at: /etc/ssh/sshd_config also you want to create a file: /etc/ssh/authorized_keys to store the public keys that want to connect to the server 
   
 /etc/ssh/sshd_config 
 Add the following to the end of the sshd_config file to for the proper setup 
 Port [Portnumber]
PermitRootLogin no
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys /etc/ssh/authorized_keys
AllowTcpForwarding yes
AllowUsers [Names of the allowed users]
PasswordAuthentication no
LoginGraceTime 30
ClientAliveInterval 300
X11Forwarding no 
 Portnumber:  Should be the portnumber you want to access your server on, it should not be 22 and should be above 1024 
 AllowUsers:  Name of the users you want to allow login with 
 If you do not plan on acessing internal server ports over an ssh tunnel, such as cockpit you might want to remove the AllowTcpForwarding option 
   
 sudo sshd -t can be used to test out the configuration before reloading 
 sudo systemctl reload sshd actually reloads the service and the configuration