Err:16 https://build.openvpn.net/debian/openvpn/stable focal Release
Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 18.196.214.178 443]
Get:17 http://packages.ros.org/ros/ubuntu focal InRelease [4679 B]
Get:18 http://packages.ros.org/ros2/ubuntu focal InRelease [4685 B]
Get:19 http://packages.ros.org/ros/ubuntu focal/main amd64 Packages [774 kB]
Get:20 http://packages.ros.org/ros2/ubuntu focal/main amd64 Packages [1189 kB]
Reading package lists... Done
E: The repository 'http://build.openvpn.net/debian/openvpn/stable focal 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.
therefore
sudo systemctl status nginx
Unit nginx.service could not be found.
Fetched 605 kB in 0s (5172 kB/s)
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76,<> line 7.)
debconf: falling back to frontend: Readline
Preconfiguring packages ...
Selecting previously unselected package nginx-common.
(Reading database ... 209833 files and directories currently installed.)
Preparing to unpack .../0-nginx-common_1.18.0-0ubuntu1.4_all.deb ...
Unpacking nginx-common (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package libnginx-mod-http-image-filter.
Preparing to unpack .../1-libnginx-mod-http-image-filter_1.18.0-0ubuntu1.4_amd64.deb ...
Unpacking libnginx-mod-http-image-filter (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package libnginx-mod-http-xslt-filter.
Preparing to unpack .../2-libnginx-mod-http-xslt-filter_1.18.0-0ubuntu1.4_amd64.deb ...
Unpacking libnginx-mod-http-xslt-filter (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package libnginx-mod-mail.
Preparing to unpack .../3-libnginx-mod-mail_1.18.0-0ubuntu1.4_amd64.deb ...
Unpacking libnginx-mod-mail (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package libnginx-mod-stream.
Preparing to unpack .../4-libnginx-mod-stream_1.18.0-0ubuntu1.4_amd64.deb ...
Unpacking libnginx-mod-stream (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package nginx-core.
Preparing to unpack .../5-nginx-core_1.18.0-0ubuntu1.4_amd64.deb ...
Unpacking nginx-core (1.18.0-0ubuntu1.4) ...
Selecting previously unselected package nginx.
Preparing to unpack .../6-nginx_1.18.0-0ubuntu1.4_all.deb ...
Unpacking nginx (1.18.0-0ubuntu1.4) ...
Setting up nginx-common (1.18.0-0ubuntu1.4) ...
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76.)
debconf: falling back to frontend: Readline
Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service -> /lib/systemd/system/nginx.service.
Setting up libnginx-mod-http-xslt-filter (1.18.0-0ubuntu1.4) ...
Setting up libnginx-mod-mail (1.18.0-0ubuntu1.4) ...
Setting up libnginx-mod-http-image-filter (1.18.0-0ubuntu1.4) ...
Setting up libnginx-mod-stream (1.18.0-0ubuntu1.4) ...
Setting up nginx-core (1.18.0-0ubuntu1.4) ...
invoke-rc.d: policy-rc.d denied execution of start.
Setting up nginx (1.18.0-0ubuntu1.4) ...
Processing triggers for systemd (245.4-4ubuntu3.17) ...
Processing triggers for man-db (2.9.1-1) ...
Processing triggers for ufw (0.36-6) ...
Rules updated for profile 'Husarnet'
However
user:~$ sudo service nginx start
user:~$ sudo service nginx status
* nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
Active: active (running)