# Proxy Reminder: Race Management Upstream Resilience

## Problem

`mnmsoft_proxy` currently fails hard at nginx startup if the upstream hostname
`race-management-web` is not resolvable at config-parse time.

Observed failure:

```text
host not found in upstream "race-management-web" in /etc/nginx/conf.d/default.conf
```

This caused the proxy container to restart in a loop whenever the
`race-management-web` container was down or not yet attached to the shared
Docker network.

## What Was Already Fixed

In `/opt/docker/apps/race-management/docker-compose.yml`:

- `db` now uses `restart: unless-stopped`
- `web` now uses `restart: unless-stopped`

That reduces the chance of the backend staying down, but the proxy should still
be made tolerant of temporary upstream absence.

## What Needs To Be Done In Proxy

Relevant proxy files:

- `/opt/docker/apps/proxy/generated/default.conf`
- possibly `/opt/docker/apps/proxy/nginx/nginx.conf`

### Goal

Avoid nginx resolving `race-management-web` only once at startup.
Instead, make nginx resolve through Docker DNS at request time or with a
short-lived resolver cache.

### Recommended Approach

Use Docker's internal DNS resolver and proxy through a variable.

Typical pattern:

```nginx
resolver 127.0.0.11 valid=10s;

location / {
    set $race_management_upstream http://race-management-web:8000;
    proxy_pass $race_management_upstream;
}
```

### Why

With a static upstream like:

```nginx
proxy_pass http://race-management-web:8000;
```

nginx may try to resolve the hostname during startup/config load. If the
container is absent at that exact moment, nginx exits and the proxy restarts.

Using `resolver 127.0.0.11` plus a variable makes nginx rely on Docker DNS more
safely at runtime.

## Also Clean Up

The proxy logs also show this warning:

```text
the "listen ... http2" directive is deprecated
```

If present, replace patterns like:

```nginx
listen 443 ssl http2;
```

with the newer form appropriate for the installed nginx version.

## After Editing

Reload/recreate the proxy stack and verify:

```bash
cd /opt/docker/apps/proxy
docker compose up -d
docker logs --tail 100 mnmsoft_proxy
```

Expected result:

- proxy stays up even if `race-management-web` is briefly unavailable during startup
- no more `host not found in upstream "race-management-web"` fatal error