id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
2180	Installation instructions fail on Ubuntu 16.04	ovenblast@…	thresh	"Installation instructions for Ubuntu were changed recently and currently cause `apt update` to fail on Ubuntu 16.04.

{{{
# apt update
Get:1 http://nginx.org/packages/ubuntu xenial InRelease [4354 B]
Hit:2 http://archive.ubuntu.com/ubuntu xenial InRelease
Hit:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
Hit:5 http://security.ubuntu.com/ubuntu xenial-security InRelease
Err:1 http://nginx.org/packages/ubuntu xenial InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ABF5BD827BD9BF62
Reading package lists... Done
W: GPG error: http://nginx.org/packages/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ABF5BD827BD9BF62
E: The repository 'http://nginx.org/packages/ubuntu xenial InRelease' is not signed.
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.
}}}

The previous version of instructions (with `apt-key add`) works fine on Ubuntu 16.04 and Ubuntu 20.04.

Tested on Docker images `ubuntu:xenial` and `ubuntu:focal`."	defect	closed	minor		documentation	1.19.x	fixed			Linux 525b07850e66 4.19.76-linuxkit #1 SMP Thu Oct 17 19:31:58 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux	n/a