cloud engineer
Here’s my custom ssh script named login.sh using multiple arguments.
#!/bin/bash if [ $# -eq 0 ] then echo 'no server supplied' exit 1 fi INPUT=$2 case "$INPUT" in abc) ssh user1@$1 ;; def) ssh user2@$1 ;; *) ssh user3@$1 ;; esac |
How to use with expected outputs.
./login.sh no server supplied ./login.sh server3 abc ssh user1@server3 ./login.sh server2 def ssh user2@server2 ./login.sh server1 ssh user3@server1 |
Here’s how to keep your SSH timeout alive for a longer period.
Edit /etc/ssh/sshd_config. Adjust interval and count max.
ClientAliveInterval 1200 ClientAliveCountMax 3 |
ClientAliveInterval is set to 1200 and ClientAliveCountMax is set to the default which is 3. This means unresponsive SSH clients will be disconnected after approximately 3600 seconds or 1 hour.
AWS LightSail now has the ability to restrict IP addresses in their firewall rules. LightSail instances can now be secured by limiting firewall rules from an IP CIDR block or a single IP address. For example, you can restrict who can SSH into your instance by limiting it to just your IP address, so only you can SSH into your machine. Another feature AWS added in their LightSail firewall is support for ping, which could be helpful for monitoring and checks.
Here’s the command to copy a secret key to a remote server.
ssh-copy-id user@servername |
This assumes you already generated a key.
When you stand up an AWS instance, it’s only accessible via SSH key using the default user, typically ec2-user.
Add password to ec2-user, then enable password authentication to ‘yes’ in SSH.
# Add password to ec2-user sudo passwd ec2-user # edit ssh config vim /etc/ssh/sshd_config # enable password authentication PasswordAuthentication yes # save file and exit |
Restart SSH service.
systemctl restart sshd.service |