# Deploying mediator

Target: Ubuntu 22.04 VPS, nginx in front, app in `/opt/mediator`.

The app runs as an unprivileged `mediator` system user, listens only on
`127.0.0.1:8080`, and nginx proxies the public domain to it. Polls live in
`/opt/mediator/data/polls.json` — that one file is the whole backup.

## One-time setup (on the server)

Copy the deploy files over and run the setup script as root:

```sh
scp deploy/mediator.service deploy/mediator.nginx.conf deploy/setup-server.sh himalia:/tmp/
ssh himalia
  cd /tmp
  sudo ./setup-server.sh <your-ssh-user> <your-domain>
```

The script creates the `mediator` user, installs the systemd unit and nginx
site, and adds a sudoers rule so your user can `systemctl restart mediator`
without a password (that keeps deploys to a single password prompt).

Then get a certificate:

```sh
sudo certbot --nginx -d <your-domain>
```

## Every deploy (from your machine)

```sh
./deploy/deploy.sh            # or: ./deploy/deploy.sh otherhost
```

Cross-compiles a static linux/amd64 binary, streams it to the server over
one ssh connection (one password prompt), swaps it in atomically, restarts
the service, and prints `active` on success.

## Useful commands on the server

```sh
systemctl status mediator
journalctl -u mediator -f
cp /opt/mediator/data/polls.json ~/polls-backup.json   # backup
```