# The extension update server

Chrome has no update channel for an unpacked extension: it reads the folder off
disk once and never looks again. This is the supported alternative — the
extension is signed into a CRX, an update manifest is published next to it, and
Chrome installs and updates it from there like any other extension.

```
droplet 159.223.129.19                          Windows box
  key.pem  ──signs──> autofirmer.crx  ──HTTPS──> Chrome (policy install)
                      updates.xml    <──polls───
```

Nothing here serves the dashboard. That still runs on the trading machine, next
to the clicker, exactly as before.

## The pieces

| | |
|---|---|
| `/opt/autofirmer-updates/key.pem` | The signing key. **The extension's identity.** |
| `/opt/autofirmer-updates/public/` | `autofirmer.crx` and `updates.xml`, served as-is |
| `deploy/pack-extension.sh` | Signs `extension/` and writes both files |
| `deploy/docker-compose.yml` | An `nginx:alpine` that serves that folder and nothing else |
| `deploy/nginx/ext.conf.template` | Rendered into the autotrader stack's `conf.d` |
| `scripts/install-extension-policy.ps1` | The Windows side: one registry entry |

Extension id: `lkjbblagjjbldlkeaaffhiopdlhniaan`, derived from the public half of
the signing key and repeated in three places that must agree — `key` in
`extension/manifest.json`, `appid` in `updates.xml`, and the forcelist entry in
the policy script. `pack-extension.sh` refuses to publish when the first two
have drifted apart, because the failure otherwise is silent: Chrome simply never
sees an update that applies to it.

**Losing `key.pem` means losing the extension.** A new key is a new id, which
means a new policy entry on every machine and a fresh install rather than an
update. It exists in one place, deliberately — it is not in the repo, and a
compromised copy would let someone else publish an extension your browsers
would trust and install.

## Ingress

This stack owns no ingress. The droplet already runs one nginx on 80/443 for
`master.juicerroom.com` and `git.juicerroom.com`, from `/opt/autotrader/deploy`;
this joins that network, and `deploy.sh` renders a server block into that
stack's `nginx/conf.d`. Two consequences:

- The rendered `ext.conf` is untracked in the autotrader repo. It survives that
  stack's pulls and deploys, but not its `bootstrap-tls.sh`, which clears
  `conf.d` — re-run `./deploy.sh` here if that ever happens.
- `deploy.sh` reloads the shared nginx, so a mistake in the template would be a
  mistake in front of the autotrader dashboard too. It runs `nginx -t` first and
  refuses to reload on a bad config, and will not install the TLS server block
  until the certificate actually exists.

## First run

```bash
cp .env.example .env      # set EXT_HOST
./bootstrap-tls.sh        # DNS check, certificate, then deploy.sh
```

`bootstrap-tls.sh` borrows the autotrader stack's certbot container and Let's
Encrypt account, reading `ACME_EMAIL` from its `.env` rather than keeping a
second copy. The A record has to point at the droplet first.

## Publishing a release

```bash
git pull && ./deploy/deploy.sh
```

`deploy.sh` packs whatever is in `extension/` at the version its `manifest.json`
declares, so **bump that version or nothing updates** — Chrome compares versions
and ignores a CRX that is not newer than what it has.

The browsers pick it up on Chrome's own schedule, roughly every five hours. They
also pick it up within seconds if the dashboard is running, because the
extension asks Chrome for a check as soon as the dashboard reports a newer
version than the one it is running.

## Installing it on a machine

From an elevated PowerShell on the Windows box:

```powershell
powershell -NoProfile -ExecutionPolicy Bypass -File scripts\install-extension-policy.ps1
```

Then remove the unpacked copy from `chrome://extensions` — it now has the same
id, and Chrome will not load both — and restart Chrome. `-Remove` undoes it;
`-Browser Edge` or `-Browser Brave` writes the same entry for those instead.

Development still works the old way: load `extension/` unpacked on a machine
with no policy entry. It keeps the same id (that is what `key` in the manifest
is for), and there it reloads itself from disk rather than asking Chrome for an
update.