Copy EC2 instance to Amazon Lightsail

gistfile1.txt

HOW TO Copy EC2 instance to Amazon Lightsail

WARNING - this is a guide to remind myself how to do it!!!!
WARNING - I'M NOT RESPONSIBLE FOR ANYTHING YOU DO WITH THIS!
WARNING - DON'T ASK ME ANY QUESTIONS ABOUT IT.
WARNING - THIS IS NOT A TUTORIAL - I'm typing this from memory.

These steps are a good approximation of what is needed but you'll 
need strong tech skills to do this.  Don't do it unless you know what you are doing.

************Start by making a backup/snapshot of the old EC2 machine************



Steps:

This assumes you are running the same operating system on both machines such as Amazon Linux 2

On the ec2 instance you need to fully upgrade to the latest version of the operating system:
sudo apt update

#clean up unused files:
sudo apt --purge autoremove


On the ec2 instance you need to shut down everything except networking and ssh.  
This ensures the backup is able to read all the files - if things like servers are running then 
they might be holding files open which might prevent them being backed up.

ref: 
https://serverfault.com/a/1057547/223657

/lib/systemd/system/rescue-ssh.target

[Unit]
Description=Rescue with network and ssh
Documentation=man:systemd.special(7)
Requires=network-online.target ssh.service
After=network-online.target ssh.service
AllowIsolate=yes

So now, you can proceed as fallows:
1. Enter in the maintenance mode:

systemctl isolate rescue-ssh.target (only ssh and networking)
2. Check the maintenance mode:

lsof -i:1-65535 (and you will only see the port of the ssh running)
3. Exit from the maintenance mode:

systemctl isolate multi-user.target (and everything is back again)

at this stage everything should be shut down.  you can check via:
sudo systemctl status

switch to /mnt

then make a backup of all the relevant files:


#upgrade to latest version
sudo apt update
sudo apt upgrade
# this command includes the ubuntu version in the name of the backup

refer here for xz/multicore compression
https://gist.github.com/bootrino/bc4a4b8bfe82180391904046c2c9e344

sudo tar cvpzP --exclude=/tmp/backup$(lsb_release -sr).tar.gz --exclude=/proc --exclude=/tmp --exclude=/dev --exclude=/sys --exclude=/run --exclude=/media --exclude=/usr/src/linux-headers* --exclude=/home/*/.gvfs --exclude=/home/*/.cache --exclude=/home/*/.local/share/Trash --exclude=/mnt/swapfile --exclude=/mnt/scratch --exclude=/var/swap.1 --exclude=/mnt/swap/swapfile -f /tmp/backup$(lsb_release -sr).tar.gz /*



then start an instance on lightsail with for example a key file name of lightsail.pem

download the pem file from lightsail

change the permissions on the pem file:
chmod ugo-rwx lightsail.pem
chmod u+rx lightsail.pem

log in to the lightsail instance:
ssh -i lightsail.pem ec2-user@<lightsailhostipaddress>

update the lightsail instance
sudo apt update
sudo apt upgrade

from the lightsail instance scp the backup file onto the lightsail instance:
scp -i lightsail.pem ec2-user@<ec2hostipaddress>:/mnt/backup.tar.gz .

important! the one file you need to ensure is the same is /etc/fstab so 
make a copy of it in your home directory:

cd ~
cp /etc/fstab .

also on the lightsail machine make a copy of authorized keys:
cd ~
cp .ssh/authorized_keys ~/.


if the machine you are copying from has swapfile then you should configure swapfile on this machine too.
follow the instructions here: 
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-memory-swap-file/

and now on the lightsail instance you need to shut down all services except ssh and network:
systemctl isolate rescue-ssh.target (only ssh and networking)

at this stage everything should be shut down.  you can check via:
sudo systemctl status

switch to /mnt
move the backup file into mount:
sudo mv ~/backup.tar.gz .

we are almost but not quite following these instructions because they are for ubuntu:
refer: https://help.ubuntu.com/community/BackupYourSystem/TAR

now restore all the files:
sudo tar -xvpzf fullbackup.tar.gz -C /  --numeric-owner

then copy the fstab file that you saved earlier from your home dir back to /etc
cp ~/fstab /etc/.

add the contents of the authorized_keys that you saved earlier into the authorized_keys file that was restored from backup
this will allow you to log into the machine with both the old and new pem files.

check the /etc/fstab file to ensure the swapfile is in it

Exit from the maintenance mode:
systemctl isolate multi-user.target (and everything is back again)


reboot

everything should nmow be working

sudo apt update
sudo apt upgrade