# Deploying .NET Web API with PostgreSQL on Debian 12 LXC

## Overview
This document outlines the steps taken to deploy a .NET Web API on a Debian 12 (Bookworm) LXC container running on Proxmox, and connect it to a PostgreSQL database accessible by the API.

---

## Prerequisites

- Debian 12 (Bookworm) LXC container on Proxmox
- Root or sudo access on the container
- Published .NET Web API DLL ready for deployment
- PostgreSQL installed on the container

---

## Step 1: Install .NET 8 Runtime and SDK

```
sudo apt update && sudo apt upgrade -y
sudo apt install -y apt-transport-https ca-certificates gnupg wget
wget https://packages.microsoft.com/config/debian/12/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
sudo apt update
sudo apt install -y dotnet-sdk-8.0 aspnetcore-runtime-8.0
dotnet --list-sdks
dotnet --list-runtimes
```

---

## Step 2: Install PostgreSQL

```
sudo apt install -y postgresql postgresql-contrib
sudo systemctl enable postgresql
sudo systemctl start postgresql
```

---

## Step 3: Create PostgreSQL User and Database

Log into psql as postgres user:

```
sudo -u postgres psql
```

Inside psql shell:

```
CREATE USER api WITH PASSWORD 'abcd1234';
CREATE DATABASE apidatabase OWNER api;
GRANT ALL PRIVILEGES ON DATABASE apidatabase TO api;
\q
```

---

## Step 4: Deploy the .NET Web API DLL

- Copy published files to `/opt/api/`
- Ensure files exist (dll, appsettings.json, etc.)

Example files present in `/opt/api`:

- `Taekwondo.WebApi.dll`
- `appsettings.json`
- `appsettings.Development.json`

---

## Step 5: Configure appsettings.json

Edit `/opt/api/appsettings.json` to include your database connection:

```
{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Database=apidatabase;Username=api;Password=abcd1234"
  }
}
```

---

## Step 6: Create systemd Service for API

Create `/etc/systemd/system/mydotnetapi.service` with:

```
[Unit]
Description=My .NET Web API
After=network.target

[Service]
WorkingDirectory=/opt/api
ExecStart=/usr/bin/dotnet /opt/api/Taekwondo.WebApi.dll
Restart=always
RestartSec=10
SyslogIdentifier=dotnet-api
User=www-data
Environment=ASPNETCORE_ENVIRONMENT=Production

[Install]
WantedBy=multi-user.target
```

Reload systemd and start service:

```
sudo systemctl daemon-reload
sudo systemctl enable mydotnetapi
sudo systemctl start mydotnetapi
sudo systemctl status mydotnetapi
```

---

## Step 7: Testing API

- Use `curl` or Postman to test API endpoints, e.g.:

```
curl http://localhost:5000/api/your-endpoint
```

- Check logs in case of issues:

```
sudo journalctl -u mydotnetapi -f
```

---

## Troubleshooting

- **Status=200/CHDIR error:** Ensure working directory exists and user permissions are correct:

```
sudo mkdir -p /opt/api
sudo chown www-data:www-data /opt/api
```

- Database connection errors: Verify `appsettings.json` connection string and PostgreSQL is running.

- Warning `could not change directory to "/root": Permission denied` in psql is safe to ignore.

---

## Notes

- Adjust firewall and reverse proxy as needed.
- Ensure PostgreSQL allows connections from your API IP if running separately.
- Tailor environment (e.g., `ASPNETCORE_ENVIRONMENT` setting) for development or production.