Install Docker Engine on Ubuntu

# Uninstall old versions
sudo apt-get remove docker docker-engine docker.io containerd runc

# Set up the repository
sudo apt-get update
sudo apt-get install \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

# Add Docker’s official GPG key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

# Install Docker Engine
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

# Test installation
sudo docker run hello-world

ref: https://docs.docker.com/engine/install/ubuntu/

Docker cmd notes

## copy file / dir from local to docker container
# single file
docker cp foo.txt [container_id]:/foo.txt
# folder - all current level's files+dir to container's app/ folder 
docker cp . [container_id]:app/