# The edge cache, and why a green deploy could still ship nothing

## The problem, measured

`tools/deploy.sh` step 5 compares `https://partly.party/gutsy/js/boot.js`, fetched the way a
browser fetches it, against the bytes just shipped. On 2026-07-26 it failed for the first time
and it was right:

```
last-modified: Sun, 26 Jul 2026 12:10:07 GMT
cache-control: max-age=14400
cf-cache-status: HIT
age: 158
```

The origin (`forum-nginx`) sends **no `Cache-Control` at all** for `/gutsy/`, so Cloudflare
applies its default 4-hour Edge TTL to `.js`. GUTS has no build step and no content hashes in
its filenames, so what the edge is holding is not an asset — it is **code**. A deploy lands on
the box and players keep running the previous build for up to four hours, with nothing anywhere
saying so.

Every check above step 5 appends `?v=$BUST`, which is exactly what makes them bypass the edge.
So six green checks were compatible with every player being served a stale game.

## The fix (needs one command run by hand)

`tools/forum-nginx-default.conf` is the container's config with a `/gutsy/` block added:

```nginx
location /gutsy/ {
    root   /usr/share/nginx/html;
    add_header Cache-Control "no-cache";
}
```

`no-cache` means *store it, but revalidate every time* — the files are small and etag'd, so a
revalidation is a 304 and costs nothing. Scoped to `/gutsy/`; no other path on partly.party is
affected.

Apply it (the copy-into-container step is gated for agents, so this is John's to run):

```bash
scp tools/forum-nginx-default.conf humanjing@100.71.119.27:/tmp/default.conf
```

```bash
ssh humanjing@100.71.119.27 "docker cp /tmp/default.conf forum-nginx:/etc/nginx/conf.d/default.conf && docker exec forum-nginx nginx -t && docker exec forum-nginx nginx -s reload"
```

`nginx -t` runs before the reload, so a syntax error refuses to load rather than taking
partly.party down.

Then confirm — this should report `cf-cache-status: DYNAMIC` or `BYPASS`, and deploy.sh step 5
should pass on the first try after every future deploy:

```bash
curl -sI https://partly.party/gutsy/js/boot.js | grep -iE "cf-cache-status|cache-control"
```

## Until then

A deploy is only live to players after the 4-hour TTL expires, or after a manual purge:
Cloudflare dashboard → partly.party → Caching → Configuration → Purge Everything.

Note the container has **no bind mount** for its nginx config, so a `docker compose up
--force-recreate` or an nginx image bump wipes this block. That is why the file lives in the
repo: re-applying it is the same two commands.