Get Environment information

Print Linux Distribution: cat /etc/os-release
Print process status: ps aux
List open file handles: find . -type f | wc -l
Print last 20 rows and wait for updates tail -n 20 -f /appdata/node1.log
Stop Docker Service sudo service docker stop
Start Docker Service sudo service docker start

Firewall

sudo firewall-cmd --list-all
sudo firewall-cmd --zone=public --add-port=8080/tcp --permanent
sudo firewall-cmd --reload

YUM

Find which package contain a command (e.g. ifconfig)

yum provides <command>
yum install net-tools

Update all packages

yum update

Update a package

yum update <packagename>

Remote Authorization with public key

Define the authorized keys on the remote machine.

scp ~/.ssh/id_rsa.pub <username>@<public_ip>

create an .ssh folder on the remote server with permission: 700

mkdir ~/.ssh
chmod 700 ~/.ssh/
cat id_rsa.pub >> ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

Create Symbolic link

ln -s ~/source_folder ~/dest_folder

Setup on Cent OS