Docker network error

When try the example in
https://docs.docker.com/get-started/part2/#build-the-app

Error:
pip network error
Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', error('Tunnel connection failed: 404 Not Found',))': /simple/flask/

Solution:
Along with below Proxy configuration in DockerFile

ENV http_proxy http://proxy-chain.xxx.com:911/
ENV https_proxy http://proxy-chain.xxx.com:912/

and use docker build command with following argument


$ docker build --no-cache --network=host -t friendlyhello .

Error
 RUN apt-get update && apt-get upgrade -y python3-pip
Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease
  Temporary failure resolving 'archive.ubuntu.com'

Solution

$ docker build --no-cache --network=host -t <dockername> .