force-ssl behind another proxy using http_x_forwarded_proto

[paucapo]

Fix for issue #3365 and pull request #3589

[jc21]

Change looks good, can you confirm that this docker image works as you expect?

[paucapo]

Seems like is working as expected, but maybe some additional tests with configurations a bit more elaborated than mine will be a good idea.

[cbenard]

This doesn't work when you have Cloudflare Tunnel (cloudflared) connecting to an https nginx endpoint and they requested HTTP.

The working code changes this:

if ($http_x_forwarded_proto = "https") {
	set $test "";
}

to this:

if ($http_x_forwarded_proto = "http") {
	set $test "H";
}

It then works as expected.

[nginxproxymanagerci]

CI Error:

/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
certbot-node: Pulling from nginxproxymanager/nginx-full
Digest: sha256:eaa2ebcb50dd87557c9a8f95a3230128d94cac1ea17800261c036e59378e7d49
Status: Image is up to date for nginxproxymanager/nginx-full:certbot-node
docker.io/nginxproxymanager/nginx-full:certbot-node
�[1;34m❯ �[1;36mBuilding Frontend ...�[0m
yarn install v1.22.22
[1/4] Resolving packages...
[2/4] Fetching packages...
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
error Command failed.
Exit code: 128
Command: git
Arguments: clone https:/tabler/tabler.git /usr/local/share/.cache/yarn/v6/.tmp/e11a93799a52aa978c82015e29fbe309
Directory: /app/frontend
Output:
Cloning into '/usr/local/share/.cache/yarn/v6/.tmp/e11a93799a52aa978c82015e29fbe309'...
error: RPC failed; curl 92 HTTP/2 stream 5 was not closed cleanly: CANCEL (err 8)
error: 2310 bytes of body are still expected
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output