博客服务器进行apt update更新时出现故障，显示“Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake:”
完整故障代码如下：
root@ecs-x-medium-2-linux-20200315094231:~# apt-get update Ign:1 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic InRelease Ign:2 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates InRelease Ign:3 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports InRelease Ign:4 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security InRelease Err:5 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443] Err:6 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443] Err:7 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443] Err:8 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443] Reading package lists... Done E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security Release' no longer has a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.
更换镜像源还是报错，不断尝试，终于解决了，方法如下：
touch /etc/apt/apt.conf.d/99verify-peer.conf \
&& echo >>/etc/apt/apt.conf.d/99verify-peer.conf "Acquire { https::Verify-Peer false }"
原因还是网络策略问题，前端可能有代理之类的东西对https进行解密和重新加密。
之后恢复正常！
root@ecs-x-medium-2-linux-20200315094231:~# touch /etc/apt/apt.conf.d/99verify-peer.conf \
> && echo >>/etc/apt/apt.conf.d/99verify-peer.conf "Acquire { https::Verify-Peer false }"
root@ecs-x-medium-2-linux-20200315094231:~# apt-get updateHit:1 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic InRelease
Get:2 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates InRelease [88.7 kB]
Get:3 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports InRelease [83.3 kB]
Get:4 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security InRelease [88.7 kB]
Get:5 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic/multiverse Sources [181 kB]
Get:6 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic/universe Sources [9,051 kB]
Get:7 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic/main Sources [829 kB]
Get:8 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic/restricted Sources [5,324 B]
Get:9 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main Sources [537 kB]
Get:10 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted Sources [34.0 kB]
Get:11 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/multiverse Sources [18.9 kB]
Get:12 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe Sources [487 kB]
Get:13 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main i386 Packages [1,589 kB]
Get:14 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main amd64 Packages [2,852 kB]
Get:15 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main Translation-en [523 kB]
Get:16 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted i386 Packages [38.6 kB]
Get:17 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted amd64 Packages [1,083 kB]
Get:18 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted Translation-en [150 kB]
Get:19 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe i386 Packages [1,635 kB]
Get:20 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe amd64 Packages [1,866 kB]
Get:21 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe Translation-en [404 kB]
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Get:24 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/multiverse Translation-en [6,088 B]
Get:25 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/main Sources [10.5 kB]
Get:26 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/universe Sources [6,600 B]
Get:27 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/main i386 Packages [53.3 kB]
Get:28 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/main amd64 Packages [53.3 kB]
Get:29 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/main Translation-en [14.6 kB]
Get:30 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/universe i386 Packages [18.1 kB]
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Get:32 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports/universe Translation-en [8,668 B]
Get:33 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/multiverse Sources [10.6 kB]
Get:34 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted Sources [31.1 kB]
Get:35 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe Sources [309 kB]
Get:36 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main Sources [290 kB]
Get:37 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main i386 Packages [1,296 kB]
Get:38 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main amd64 Packages [2,518 kB]
Get:39 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main Translation-en [436 kB]
Get:40 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted amd64 Packages [1,053 kB]
Get:41 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted i386 Packages [31.9 kB]
Get:42 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted Translation-en [146 kB]
Get:43 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe amd64 Packages [1,253 kB]
Get:44 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe i386 Packages [1,047 kB]
Get:45 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe Translation-en [290 kB]
Get:46 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/multiverse amd64 Packages [19.1 kB]
Get:47 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/multiverse i386 Packages [6,008 B]
Get:48 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/multiverse Translation-en [3,908 B]
Fetched 30.5 MB in 17s (1,792 kB/s)
Reading package lists... Done
