直到几天前，它Dockerfile都工作正常，当我今天尝试再次构建它时，它在终端中给出以下错误。我尝试使用多个 docker 基础映像，但仍然给出相同的错误。谁能帮我这个？我不认为我错过了什么。如果我错过了，它应该早先给我错误，但为什么现在呢？
Err:1 http://security.ubuntu.com/ubuntu xenial-security InRelease
Temporary failure resolving 'security.ubuntu.com'
Err:2 http://archive.ubuntu.com/ubuntu xenial InRelease
Temporary failure resolving 'archive.ubuntu.com'
Err:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
Temporary failure resolving 'archive.ubuntu.com'
Err:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
Temporary failure resolving 'archive.ubuntu.com'
Reading package lists...
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease Temporary failure resolving 'security.ubuntu.com'
W: Some index files …