ssh

• Secure connection between computers
• Key-pairs are generated at user level (~/.ssh)
• id_rsa: secret file and never share
• id_rsa.pub: share with github, heroku, etc
• Private key files should have 400 permissions

ssh "user@hostname"
ssh "[email protected]"

-T

• Test connection

ssh -T "[email protected]" # Accept 'yes'

-l (Login name / User)

• Specify user
• You can also use the syntax user@host

ssh "192.168.1.10" -l "root"

-p (Port)

• Specify port

ssh "root@localhost" -p "9090"

-i (Identity file)

• Specify the private key

ssh "root@localhost" -i "private_key"

-L

• Port tunnel

ssh "root@localhost" -L # or -D and -R

SSH server

• In a VM, the bridge mode must be enabled to use SSH
• /etc/ssh/sshd_config: Configuration file for a ssh server
• ~/.ssh/authorized_keys/: Stores public keys of the allowed clients

# Install ssh-server
apt install openssh-server

# Check ssh service
systemctl status ssh
ps -ef | grep sshd # /usr/sbin/sshd

# Get ip of the machine
ip addr # enp0s3 (192.168.0.109)

# Test connection to itself
ssh localhost