Docker on Ubuntu 18.04

1. Follow the instruction from here

First, update your existing list of packages:

sudo apt update

Next, install a few prerequisite packages which let apt use packages over HTTPS:

sudo apt install apt-transport-https ca-certificates curl software-properties-common

Then add the GPG key for the official Docker repository to your system:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Add the Docker repository to APT sources:

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable"

Next, update the package database with the Docker packages from the newly added repo:

sudo apt update

Make sure you are about to install from the Docker repo instead of the default Ubuntu repo:

apt-cache policy docker-ce

You’ll see output like this, although the version number for Docker may be different:

Output of apt-cache policy docker-ce

docker-ce:
  Installed: (none)
  Candidate: 18.03.1~ce~3-0~ubuntu
  Version table:
     18.03.1~ce~3-0~ubuntu 500
        500 https://download.docker.com/linux/ubuntu bionic/stable amd64 Packages

Notice that docker-ce is not installed, but the candidate for installation is from the Docker repository for Ubuntu 18.04 (bionic).

Finally, install Docker:

sudo apt install docker-ce

Docker should now be installed, the daemon started, and the process enabled to start on boot. Check that it’s running:

sudo systemctl status docker

2. Cannot install docker yii2, follow instructions below:

1. sudo apt-get remove docker-compose
2. sudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
3. sudo chmod +x /usr/local/bin/docker-compose
4. sudo ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose