Files
minstrel/docs/hosting.md
T
bvandeusenandClaude Opus 5.5 522503e011 docs: hosting guide and security notes; README setup and HTTPS guidance (M462 #4986)
- docs/hosting.md: LAN vs internet; binding 4533 to 127.0.0.1 behind an
  HTTPS proxy (Caddy example, no buffering, long read timeouts for SSE and
  streams); the Client IP detection hop count (default 1, so 0 with no
  proxy or clients can forge X-Forwarded-For); the public address that
  password-reset links need; finding the setup token.
- docs/security.md: sessions, API keys, rate limits, headers and CSP; why
  CSRF rests on SameSite=Strict plus JSON-only cookie writes; the Subsonic
  password column, including the known issue that admin reset-password
  writes the login password there (#5026); why Android allows plain HTTP;
  the CI publish gate.
- README: keeps the LAN-first port mapping with a pointer for internet
  hosts, scopes "plain http:// is fine" to trusted networks, explains the
  setup token in first-run step 1, and links both docs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-06 10:37:32 -04:00

3.4 KiB

Hosting Minstrel

Minstrel serves plain HTTP on port 4533 and never terminates TLS itself. On a home network or a VPN you trust, that is all you need. Once the server is reachable from the internet, put it behind a reverse proxy that speaks HTTPS, and tell Minstrel about that proxy. This page covers both.

On a LAN or VPN

Publish the port to the network and use http://<host>:4533:

    ports: ['4533:4533']

If nothing sits in front of Minstrel, set Admin → Integrations → Client IP detection to 0. It defaults to 1, which assumes one proxy (see below for why that matters).

On the internet

Three things, all required:

  1. Don't publish 4533 to the world. Bind it to the loopback interface so only the proxy on the same host can reach it:

        ports: ['127.0.0.1:4533:4533']
    

    If the proxy runs in another container on the same Docker network, drop ports: entirely and point the proxy at minstrel:4533.

  2. Terminate HTTPS at a reverse proxy. Any proxy works. With Caddy, which gets and renews certificates by itself:

    music.example.com {
        reverse_proxy 127.0.0.1:4533
    }
    

    Two settings matter for every proxy:

    • Don't buffer responses. Live updates use Server-Sent Events and audio is streamed; a buffering proxy holds both back. Caddy streams by default. For nginx, set proxy_buffering off;.
    • Allow long-lived responses. An event stream stays open for as long as the app is. Raise the proxy's read timeout well past a minute (nginx: proxy_read_timeout 1h;).
  3. Tell Minstrel where it lives, in Admin → Integrations:

    • Client IP detection: the number of proxies in front of Minstrel. One proxy (Caddy, Traefik, nginx) is 1; Cloudflare in front of Traefik is 2. Minstrel uses this to find the real client address, for login rate limits and the sessions list, and to tell whether a request arrived over HTTPS.
    • Public address: the URL people use, e.g. https://music.example.com. Password-reset emails link here. Until it is set, no reset email is sent, so a forged Host header can never put a reset token on a link to someone else's server.

Why the proxy count matters

Minstrel only believes X-Forwarded-For and X-Forwarded-Proto from the number of proxies you configure, counted from the right. Set it too high, or leave it at the default of 1 with no proxy in front, and a client can write those headers itself: it could claim any address to slip past the per-address login limit, or claim HTTPS. With no proxy, set it to 0.

When the proxy reports HTTPS, Minstrel marks the session cookie Secure and sends Strict-Transport-Security. Over plain HTTP it does neither, and it never redirects to HTTPS, so LAN use keeps working unchanged.

First account

A fresh server with no accounts prints a setup token in its log:

docker compose logs minstrel | grep setup_token

Creating the first account (which becomes the admin) requires that token, so whoever reaches a newly exposed server first can't claim it. The token changes on every restart until an account exists.

Android app

The app connects over whatever URL you give it, HTTP or HTTPS. Once the server has a public HTTPS address, give the app that address so the session cookie never crosses the internet unencrypted. See security notes for why plain HTTP is still allowed.