[ubuntu|docker]auto select fastest apt mirror

Dockerfile

FROM ubuntu
RUN apt-get update -y \
	&& apt-get install -y wget \
	&& wget -O netselect.deb http://http.us.debian.org/debian/pool/main/n/netselect/netselect_0.3.ds1-28+b1_`dpkg --print-architecture`.deb \
	&& dpkg -i netselect.deb \
	&& rm netselect.deb \
	&& sed -r -i -e "s#http://(archive|security)\.ubuntu\.com/ubuntu/?#$(netselect -v -s1 -t20 `wget -q -O- https://launchpad.net/ubuntu/+archivemirrors | grep -P -B8 "statusUP|statusSIX" | grep -o -P "http://[^\"]*"`|grep -P -o 'http://.+$')#g" /etc/apt/sources.list