I installed this on a fresh Ubuntu 20.04.2 LTS server.

Installing Docker

$ sudo apt-get update
$ sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
    lsb-release
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
$ echo \
  "deb [arch=amd64 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
$ sudo apt-get update
$ sudo apt-get install docker-ce docker-ce-cli containerd.io

Installing Docker-Compose

$ sudo curl -L "https://github.com/docker/compose/releases/download/1.28.5/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
$ sudo chmod +x /usr/local/bin/docker-compose

Managing Docker as a non-root user

$ sudo groupadd docker
$ sudo usermod -aG docker $USER
$ sudo reboot

Using a SMB Share

If you’d like to use a SMB share for your Media and Consume folder do the following commands. You will be prompted to enter the password for the SMB share after the final line. Replace the username and path to your documents with your values for your SMB share.

$ sudo apt-get install cifs-utils
$ mkdir Documents
$ chown 1000:1000 Documents
$ sudo mount -t cifs -o username=username,uid=1000,gid=1000 //server-ip-address/path-to-documents /home/administrator/Documents

Create folders called Consume and Media in the Documents folder. When you are prompted for the directory to your media use the following:

/home/administrator/Documents/Consume
/home/administrator/Documents/Media

Installing Paperless-ng

$ wget https://raw.githubusercontent.com/jonaswinkler/paperless-ng/master/install-paperless-ng.sh
$ chmod +x install-paperless-ng.sh
$ ./install-paperless-ng.sh

Follow the prompts to setup Paperless-ng. You can accept the default options by pressing enter. The only value you need to fill in is the password.