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cloud engineer

reboot

Check Reboot After Updates

Here’s the command to check if the system needs a reboot after running yum update.

Must be root or run it sudo.

$ needs-restarting -r ; echo $?
Core libraries or services have been updated:
  openssl-libs -> 1:1.0.2k-21.el7_9
  kernel -> 3.10.0-1160.31.1.el7
  dbus -> 1:1.10.24-15.el7
  linux-firmware -> 20200421-80.git78c0348.el7_9
  glibc -> 2.17-324.el7_9
  systemd -> 219-78.el7_9.3
 
Reboot is required to ensure that your system benefits from these updates.
 
More information:
https://access.redhat.com/solutions/27943
1

In this instance, it requires a reboot due to a new kernel.

Reboot Instance Script

Here’s a new script to reboot a Lightsail instance based on input.

#!/bin/bash
echo 'Choose a server to reboot ...'
echo '1) server-one'
echo '2) server-two'
echo '3) server-three'
echo '4) server-four'
echo '5) sever-five'
echo 'q) Quit'
read -p 'Choose a server to reboot: ' server
case $server in 
	1)
		echo 'Rebooting server-one ...'
		aws lightsail reboot-instance --instance-name server-one
		echo 'Done'
		;;
	2)
	        echo 'Rebooting server-two ...'
		aws lightsail reboot-instance --instance-name server-two
		echo 'Done'
		;;
	3)
		echo 'Rebooting server-three ...'
		aws lightsail reboot-instance --instance-name server-three
		echo 'Done'
		;;
	4)
		echo 'Rebooting server-four ...'
		aws lightsail reboot-instance --instance-name server-four
		echo 'Done'
		;;
	5)
		echo 'Rebooting server-five ...'
		aws lightsail reboot-instance --instance-name server-five
		echo 'Done'
		;;
	q)
		echo 'Quit'
		;;
	*)
		echo 'Invalid option' $server
		;;
esac

Assuming awscli is working and correct permission is granted to user.

Ansible Run Updates

Here’s a simple adhoc to run updates on systems in Ansible. 

ansible servers -m apt -a "upgrade=yes update_cache=yes" -b

Results:

server | SUCCESS => {
    "changed": false, 
    "msg": "Reading package lists...
     Building dependency tree...
     Reading state information...
     Calculating upgrade...
     0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.", 
    "stderr": "", 
    "stderr_lines": [], 
    "stdout": "Reading package lists...
     Building dependency tree...
     Reading state information...
     Calculating upgrade...
     0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.", 
    "stdout_lines": [
        "Reading package lists...", 
        "Building dependency tree...", 
        "Reading state information...", 
        "Calculating upgrade...", 
        "0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded."
    ]
}

If you want to reboot a remote server.

ansible servers -m "reboot" -b

AWS EFS /etc/fstab

To automatically mount a EFS volume after each reboot, you’ll need to add the following format to /etc/fstab.

You can use the DNS name given by AWS.

fs-12345678:/ /mnt/efs efs defaults,_netdev 0 0

Or the IP address.

10.0.0.22:/ /mnt/efs efs defaults,_netdev 0 0

Mount all with fake and verbose.

mount -fav