请教一下构建docker失败的问题

[nihaolix]

Dockerfile:1

1 | >>> FROM ubuntu:20.04 2 | RUN apt update -y && apt install ca-certificates -y && \ 3 | sh -c 'echo "deb https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe multiverse\ndeb https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe multiverse\ndeb https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe multiverse\ndeb https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe multiverse" > /etc/apt/sources.list' && \

ERROR: failed to solve: DeadlineExceeded: DeadlineExceeded: DeadlineExceeded: ubuntu:20.04: failed to resolve source metadata for docker.io/library/ubuntu:20.04: failed to do request: Head "https://registry-1.docker.io/v2/library/ubuntu/manifests/20.04": dial tcp [2a03:2880:f12a:83:face:b00c:0:25de]:443: i/o timeout

出现了这个错误怎么解决呀

[Matthew-WangT]

前段时间docker被墙了，如果是这个问题的话就需要科学上网环境，并正确配置docker的代理