upvoters/README.md

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# upvoters ☝️
upvoters is a basic anonymous voting system that can be added to a blog.
I recently reworked my personal blog with the Hugo Bear blog theme.
I came across the [creator's (Herman Martinus) blogging site](https://herman.bearblog.dev/) which had this really cool anonymous upvote system.
I wanted something similar and decided to implement it myself.
The goal is maximum simplicity.
## Table of Contents
- [Requirements](#requirements)
- [Configuration](#configuration)
- [Running locally](#running-locally)
- [API](#api)
- [Running tests](#running-tests)
- [Actual deployment](#actual-deployment)
- [License](#license)
## Requirements
- Rust (stable)
- PostgreSQL 16
## Configuration
The following environment variables are required:
| Variable | Description |
|------------------------------|----------------------------------------------------------------------------------------|
| `POSTGRES_CONNECTION_STRING` | PostgreSQL connection string (e.g. `postgres://user:password@localhost:5432/upvoters`) |
| `ALLOWED_ORIGINS` | Comma-separated list of allowed CORS origins (e.g. `localhost:1313,example.com`) |
| `PORT` | Port to listen on (default: `3000`) |
## Running locally
### With Docker Compose
Builds and starts both the database and app:
```sh
docker compose up --build
```
The server will be available at `http://localhost:3000`.
### Without Docker
Start the database:
```sh
docker compose up -d db
```
Run the server:
```sh
POSTGRES_CONNECTION_STRING=postgres://uprs:password123@localhost:5432/uprs cargo run
```
The server listens on port `3000`.
## API
| Method | Endpoint | Description |
|---|---|---|
| `GET` | `/health` | Health check |
| `POST` | `/posts/{slug}/vote` | Upvote a post |
| `DELETE` | `/posts/{slug}/vote` | Remove a vote from a post |
| `GET` | `/posts/{slug}/votes` | Get vote count and whether the current user has voted |
Voter identity is tracked via a `voter_id` cookie. One is set automatically on first request.
### `GET /posts/{slug}/votes` response
```json
{
"vote_count": 42,
"voted": true
}
```
## Running tests
Tests require a running PostgreSQL instance at `postgres://uprs:password123@localhost:5432/uprs`.
```sh
cargo test
```
## Actual deployment
Here are the instructions for how I deployed this service. You might be able to just run it through the docker-compose on a VPS but I already had a postgres server set up:
1. Install dependencies (rust/postgres) (For debian server).
```bash
sudo apt update
sudo apt install -y postgresql postgresql-contrib
```
2. Create `postgres` user to manage postgres and `upvoters` user to run the app:
```bash
# Create the system user that will run the app
sudo useradd --system --home /opt/upvoters --create-home upvoters
# Create the PostgreSQL role with peer auth (no password needed)
sudo -u postgres psql -c "CREATE USER upvoters;"
sudo -u postgres psql -c "CREATE DATABASE upvoters OWNER upvoters;"
# Enable peer auth for the upvoters role (append to pg_hba.conf)
echo "local upvoters upvoters peer" | sudo tee -a /etc/postgresql/16/main/pg_hba.conf
sudo systemctl reload postgresql
```
3. Create the votes table as the `upvoters` user
```bash
sudo -u upvoters psql upvoters
```
```sql
CREATE EXTENSION IF NOT EXISTS pgcrypto;
CREATE TABLE IF NOT EXISTS votes (
slug text not null,
voter_id uuid not null,
created_at timestamptz NOT NULL DEFAULT timezone('utc'::text, now()),
primary key (slug, voter_id)
);
```
4. Download the binary (You can also install rust and build yourself if you prefer). Replace `v0.2.0` with the latest release tag.
```bash
sudo curl https://forge.alexselimov.com/aselimov/upvoters/releases/download/v0.2.0/upvoters-linux-x86_64 --output /opt/upvoters/upvoters
sudo chmod +x /opt/upvoters/upvoters
sudo chown upvoters /opt/upvoters/upvoters
```
5. Create a systemd service at /etc/systemd/system/upvoters.service
```
[Unit]
Description=upvoters rust backend
After=network.target postgresql.service
[Service]
User=upvoters
Group=upvoters
WorkingDirectory=/opt/upvoters
ExecStart=/opt/upvoters/upvoters
Restart=on-failure
# The below connection string works if you have peer auth enabled and have postgresql running on
# a socket
Environment='POSTGRES_CONNECTION_STRING=postgresql:///upvoters?host=/var/run/postgresql'
Environment='ALLOWED_ORIGINS=https://example.com'
# Specify a PORT if the default 3000 is already taken
Environment='PORT=3000'
[Install]
WantedBy=multi-user.target
```
6. Enable and start the service
```bash
sudo systemctl enable --now upvoters
```
7. Test from VPS using curl
```bash
curl https://example.com/api/posts/tests/votes
```
## License
MIT — see [LICENSE](LICENSE).