Linux hot command for solutions

Install node red

pi@raspberry:~ $ bash <(curl -sL https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/update-nodejs-and-nodered)

Auto Run NODE RED On Boot

To do that you can run the command bellow

pi@raspberry:~ $ sudo systemctl enable nodered.service

Then, for the autostart to take effect restart your Pi:

pi@raspberry:~ $ sudo reboot

How to completely uninstall docker

Step 1

dpkg -l | grep -i docker

To identify what installed package you have:

Step 2

sudo apt-get purge -y docker-engine docker docker.io docker-ce  
sudo apt-get autoremove -y --purge docker-engine docker docker.io docker-ce  

The above commands will not remove images, containers, volumes, or user created configuration files on your host. If you wish to delete all images, containers, and volumes run the following commands:

sudo rm -rf /var/lib/docker
sudo rm /etc/apparmor.d/docker
sudo groupdel docker
sudo rm -rf /var/run/docker.sock

You have removed Docker from the system completely.

Docker: Error response from daemon: Unknown runtime specified nvidia.

Solution:

Step 1  Install the repository for your distribution by following the instructions

curl -s -L https://nvidia.github.io/nvidia-docker/gpgkey | \
  sudo apt-key add -
distribution=$(. /etc/os-release;echo $ID$VERSION_ID)
curl -s -L https://nvidia.github.io/nvidia-docker/$distribution/nvidia-docker.list | \
  sudo tee /etc/apt/sources.list.d/nvidia-docker.list
sudo apt-get update

Step 2   Install the nvidia-docker2 package and reload the Docker daemon configuration:

sudo yum install nvidia-docker2
sudo pkill -SIGHUP dockerd

Clean Cache with 

sudo sh -c "echo 1 > /proc/sys/vm/drop_caches"

Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: connect: permission denied.

If you have created the docker group and add your user to the docker group but still get the error then:

Do this

$ newgrp docker

and Verify that you can run docker commands without sudo.

$ docker run hello-world