学习Docker在Ubuntu容器中使用apt-get update命令遇到如下网络连接错误：
$ docker run -it ubuntu root@3c5e3b049c88:/# apt-get update Err:1 http://archive.ubuntu.com/ubuntu bionic InRelease Temporary failure resolving ‘archive.ubuntu.com‘ Err:2 http://security.ubuntu.com/ubuntu bionic-security InRelease Temporary failure resolving ‘security.ubuntu.com‘ Err:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease Temporary failure resolving ‘archive.ubuntu.com‘ Err:4 http://archive.ubuntu.com/ubuntu bionic-backports InRelease Temporary failure resolving ‘archive.ubuntu.com‘ Reading package lists... Done W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic/InRelease Temporary failure resolving ‘archive.ubuntu.com‘ W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease Temporary failure resolving ‘archive.ubuntu.com‘ W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease Temporary failure resolving ‘archive.ubuntu.com‘ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease Temporary failure resolving ‘security.ubuntu.com‘ W: Some index files failed to download. They have been ignored, or old ones used instead.
搜索各种解决方案，改容器dns的，改容器ip的都有，过程都比较复杂，要想办法在容器内修改配置文件，或在容器外改好在通过数据绑定传入容器。
最后发现有人通过--net=host参数改变容器网络模式解决，实验后果然解决问题。
$ docker run -it --name test --net=host ubuntu root@localhost:/# apt-get update Get:1 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB] Get:2 http://archive.ubuntu.com/ubuntu bionic InRelease [242 kB] Get:3 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 Packages [839 kB] Get:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB] Get:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB] Get:6 http://archive.ubuntu.com/ubuntu bionic/multiverse amd64 Packages [186 kB] Get:7 http://security.ubuntu.com/ubuntu bionic-security/restricted amd64 Packages [44.6 kB] Get:8 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64 Packages [8213 B] Get:9 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages [889 kB] Get:10 http://archive.ubuntu.com/ubuntu bionic/restricted amd64 Packages [13.5 kB] Get:11 http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages [11.3 MB] Get:12 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages [1344 kB] Get:13 http://archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 Packages [12.6 kB] Get:14 http://archive.ubuntu.com/ubuntu bionic-updates/restricted amd64 Packages [59.0 kB] Get:15 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages [1183 kB] Get:16 http://archive.ubuntu.com/ubuntu bionic-updates/universe amd64 Packages [1371 kB] Get:17 http://archive.ubuntu.com/ubuntu bionic-backports/universe amd64 Packages [4247 B] Get:18 http://archive.ubuntu.com/ubuntu bionic-backports/main amd64 Packages [2496 B] Fetched 17.8 MB in 8s (2116 kB/s) Reading package lists... Done root@localhost:/#