usda-vision/docs/HOST_IP_CONFIGURATION.md

# Host IP Configuration for Supabase

## Overview

The Supabase `config.toml` file uses the `site_url` setting to configure authentication redirects. Instead of hardcoding the host IP address, we now use environment variables that are automatically detected from the host machine.

## Problem

Previously, the `site_url` was hardcoded (e.g., `http://exp-dash:3000`), which:
- Doesn't work when the host IP changes
- Requires manual updates for different environments
- Is not portable across different machines

## Solution

We now use the `HOST_SITE_URL` environment variable, which is automatically detected using the host machine's IP address.

## Usage

### Automatic Detection (Recommended)

Use the provided scripts to automatically detect and set the host IP:

```bash
# Option 1: Source the environment setup script
source ./scripts/set-host-env.sh

# Then run Supabase CLI commands normally
supabase start
supabase db reset
```

Or use the wrapper script that does this automatically:

```bash
# Use the wrapper script for Supabase CLI commands
./scripts/supabase-with-env.sh start
./scripts/supabase-with-env.sh db reset
```

### Manual Configuration

If automatic detection doesn't work or you want to use a specific IP:

```bash
# Set the environment variable manually
export HOST_SITE_URL="http://192.168.1.100:3000"

# Or with a different port
export HOST_SITE_URL="http://192.168.1.100:8080"

# Then run Supabase commands
supabase start
```

### For Docker Compose

If you're using Docker Compose and need to set this for Supabase CLI commands run on the host:

```bash
# Before running docker compose or Supabase CLI
export HOST_SITE_URL="http://$(./scripts/get-host-ip.sh):3000"
docker compose up -d
```

Or add it to your shell profile (`~/.bashrc` or `~/.zshrc`):

```bash
# Add to ~/.bashrc or ~/.zshrc
export HOST_SITE_URL="http://$(/path/to/USDA-VISION/scripts/get-host-ip.sh):3000"
```

## How It Works

1. **IP Detection Script** (`scripts/get-host-ip.sh`):
   - Tries multiple methods to detect the host IP
   - Works both inside Docker containers and on the host machine
   - Falls back to `127.0.0.1` if detection fails

2. **Environment Setup Script** (`scripts/set-host-env.sh`):
   - Calls the IP detection script
   - Sets `HOST_SITE_URL` environment variable
   - Can be sourced to set the variable in your current shell

3. **Supabase Wrapper Script** (`scripts/supabase-with-env.sh`):
   - Automatically sets `HOST_SITE_URL` before running Supabase CLI
   - Transparent wrapper - just use it instead of `supabase` command

4. **Config File** (`supabase/config.toml`):
   - Uses `env(HOST_SITE_URL)` to read the environment variable
   - Supabase CLI automatically substitutes the value

## Detection Methods

The IP detection script tries these methods in order:

1. **Default Gateway** (for containers): Gets the gateway IP which is typically the host
2. **host.docker.internal**: Uses Docker's special DNS name (if available)
3. **Network Interface**: Checks common network interfaces (eth0, enp0s8, etc.)
4. **Hostname Resolution**: Uses `hostname -I` to get the host IP
5. **Fallback**: Returns `127.0.0.1` if all methods fail

## Troubleshooting

### IP Detection Fails

If the script can't detect the IP:

1. **Check network interfaces**:
   ```bash
   ip addr show
   # or
   ifconfig
   ```

2. **Manually set the IP**:
   ```bash
   export HOST_SITE_URL="http://YOUR_ACTUAL_IP:3000"
   ```

3. **Verify the IP is accessible**:
   ```bash
   ping $(./scripts/get-host-ip.sh)
   ```

### Supabase CLI Doesn't Use the Variable

Make sure you:
1. Set `HOST_SITE_URL` before running Supabase CLI
2. Run Supabase CLI from the project root (where `supabase/` directory is)
3. Check that `config.toml` uses `env(HOST_SITE_URL)` syntax

### Port Mismatch

If your React app runs on a different port, adjust the port in the URL:

```bash
export HOST_SITE_URL="http://$(./scripts/get-host-ip.sh):8080"
```

## Example Workflow

```bash
# 1. Navigate to project root
cd /path/to/USDA-VISION

# 2. Set the environment variable (automatic detection)
source ./scripts/set-host-env.sh

# 3. Verify it's set
echo $HOST_SITE_URL
# Output: http://192.168.1.100:3000

# 4. Start Supabase
supabase start

# Or use the wrapper script (does steps 2-4 automatically)
./scripts/supabase-with-env.sh start
```

## Integration with Docker Compose

If you're running Supabase via Docker Compose (not CLI), the containers use their own networking. The `HOST_SITE_URL` is primarily for Supabase CLI commands that run on the host machine.

For container-to-container communication, use Docker service names (e.g., `http://web:8080`).

For browser-based redirects from Supabase Auth back to your React app, use the actual host IP that the browser can access.