Set up docker in Ubuntu

Install docker in Ubuntu

Set up the repository:

sudo apt-get update

sudo apt-get install -y \
   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

Install the docker engine and tools:

sudo apt-get update
sudo apt-get install -y docker-ce docker-ce-cli containerd.io docker-compose

Manage the docker as a non-root user:

sudo groupadd -f docker
sudo usermod -aG docker $USER
newgrp docker

Log out and log in to your desktop again.

Incorporate network setting

Before applying this configuration, ensure your host machine is behind the proxy server and uses special DNS.

Proxy

Create a systemd drop-in directory for the docker service:
```
sudo mkdir -p /etc/systemd/system/docker.service.d
```

Create a file named /etc/systemd/system/docker.service.d/http-proxy.conf that adds PROXY related environment variables:

[Service]
Environment="HTTP_PROXY=http://proxy_ip:port"
Environment="HTTPS_PROXY=https://proxy_ip:port"
Environment="NO_PROXY=localhost,127.0.0.1,tic"

Restart the docker daemon:

sudo systemctl daemon-reload
sudo systemctl restart docker

Verify that the configuration has been loaded and matches the changes you made:
```
sudo systemctl show --property=Environment docker
```

Add proxy configurations to ~/.docker/config.json file to configure the Docker client:

{
   "proxies": {
      "default": {
         "httpProxy": "http://proxy_ip:port",
         "httpsProxy": "http://proxy_ip:port",
         "noProxy": "localhost,127.0.0.1,tic"
      }
   }
}

DNS

Create a file named /etc/docker/daemon.json that adds the dns key:

{
  "dns": [
    "dns_ip",
    "dns_ip"
  ]
}

Restart the docker daemon:
```
sudo systemctl restart docker
```

For more details, please refer the official docker document.