nginx: emit relative redirects so a mapped host port survives directory redirects

[mormegil6]

Problem

nginx builds a directory redirect (a request missing its trailing slash) as an absolute URL using its own internal listen port. When Earshot's transcoder container is published on a different host port (docker run -p 8081:80, or behind a reverse proxy / VPN bind), that external port is dropped:

$ curl -sI http://host:8081/webtools
HTTP/1.1 301 Moved Permanently
Location: http://host/webtools/      # port 80, wrong service

So /webtools, /dash, or any directory reached without a trailing slash sends the browser to the wrong place unless it happens to be served on port 80.

Fix

absolute_redirect off; at the HTTP server level makes nginx emit a relative Location, which the browser resolves against the request URL and keeps the port:

$ curl -sI http://host:8081/webtools
HTTP/1.1 301 Moved Permanently
Location: /webtools/                 # relative, resolves to :8081/webtools/

$ curl -sIL http://host:8081/webtools | tail -1
HTTP/1.1 200 OK

One directive, applied to both nginx.conf and nginx-no-ssl.conf. No behaviour change for deployments served directly on 80/443.

Verified

On a live deployment publishing the transcoder on :8081 behind a Docker + Tailscale bind: before, /webtools 301'd to http://host/webtools/ (dropped port); after, it 301s to a relative /webtools/ and the follow-up request lands on :8081 with 200.

[Copilot]

Pull request overview

Updates the transcoder’s nginx configuration so directory (trailing-slash) redirects don’t drop externally mapped host ports when the container is published behind Docker port mapping or a reverse proxy.

Changes:

• Disable absolute redirects at the server level using absolute_redirect off; in the SSL-enabled config.
• Apply the same directive to the non-SSL nginx config for consistent behavior.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
nginx-transcoder/nginx.conf	Disables absolute redirects in the server block so directory redirects remain relative and preserve mapped ports.
nginx-transcoder/nginx-no-ssl.conf	Mirrors the same absolute_redirect off; change for non-SSL deployments to keep redirect behavior consistent.

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