Miscellanies about initializing an Ubuntu Server

Having trouble with Windows SSH: Unprotected private key file

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@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
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Permissions for 'private' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
Load key "private": bad permissions

You can use icacls in windows instead of chmod to adjust file permission.

icacls .\private.key /inheritance:r
icacls .\private.key /grant:r "%username%":"(R)"

Having trouble with SSH login: connection reset after idle for some time

[Ineffective]

ssh -o TCPKeepAlive=true root@host.com

For long term use you should modify /etc/ssh/sshd_config as follows:

ClientAliveInterval 30
ClientAliveCountMax 60

Error: Got permission denied while trying to connect to the Docker daemon socket

Follow the just a few steps and you do not have to access docker images with superuser privileges.

sudo groupadd docker
sudo gpasswd -a ${USER} docker
sudo service docker restart

Add a new sudoer

sudo usermod -aG sudo <username>