2089 Tls Configuration 565f8deb

# TLS/SSL Configuration Guide

This guide explains how to configure TLS/SSL encryption for the MCP Gateway and nginx reverse proxy in Docker Compose deployments.

**⚠️ Important: TLS is OPTIONAL and DISABLED by default.** The default deployment uses HTTP-only for simplicity. Enable TLS only when needed for production or testing secure connections.

---

## Quick Start: Zero-Config TLS

The fastest way to enable HTTPS is using the `--profile tls` Docker Compose profile. This automatically generates self-signed certificates and configures nginx with TLS—no manual configuration required.

### One Command

```bash
make compose-tls
```

This starts the full stack with:

- **HTTP:** `http://localhost:8080`
- **HTTPS:** `https://localhost:8443`
- **Admin UI:** `https://localhost:8443/admin`

### What Happens

1. The `cert_init` container checks if certificates exist in `./certs/`
2. If missing, it auto-generates a self-signed certificate valid for 365 days
3. The `nginx_tls` service starts with TLS enabled on port 8443
4. Both HTTP (8080) and HTTPS (8443) are available

### Bringing Your Own Certificates

You can use your own CA-signed certificates or custom certificates instead of auto-generated self-signed ones. The TLS profile supports both unencrypted and passphrase-protected private keys.

#### Option 1: Unencrypted Private Key (No Passphrase)

This is the simplest approach for certificates without passphrase protection:

```bash
# Create certs directory and add your certificates
mkdir -p certs
cp /path/to/your/certificate.pem certs/cert.pem
cp /path/to/your/private-key.pem certs/key.pem

# Start the TLS stack (will use existing certs)
make compose-tls
```

The `cert_init` container detects existing certificates and skips generation.

#### Option 2: Passphrase-Protected Private Key

For enhanced security, you can use a passphrase-protected private key. The system will automatically decrypt it for nginx:

```bash
# Create certs directory and add your certificates
mkdir -p certs
cp /path/to/your/certificate.pem certs/cert.pem
cp /path/to/your/encrypted-key.pem certs/key-encrypted.pem

# Add passphrase to .env file
echo "KEY_FILE_PASSWORD=your-passphrase" >> .env

# Start the TLS stack (will auto-decrypt for nginx)
make compose-tls
```

**How it works:**

- The `cert_init` container detects `key-encrypted.pem` and `KEY_FILE_PASSWORD`
- It decrypts `key-encrypted.pem` to `key.pem` using `openssl rsa`
- Nginx uses the decrypted `key.pem` (nginx doesn't support passphrase-protected keys natively)
- Your original encrypted key remains safe in `key-encrypted.pem`

#### Option 3: Generate Self-Signed with Passphrase

To generate a new self-signed certificate with passphrase protection:

```bash
# Generate passphrase-protected certificate
make certs-passphrase

# Add passphrase to .env file
echo "KEY_FILE_PASSWORD=your-passphrase" >> .env

# Start the TLS stack
make compose-tls
```

This creates:
- `certs/cert.pem` - Certificate file
- `certs/key-encrypted.pem` - Passphrase-protected private key
- `certs/key.pem` - Decrypted private key (generated by cert_init for nginx)

### TLS Profile Commands

| Command | Description |
|---------|-------------|
| `make compose-tls` | Start with TLS (HTTP + HTTPS both available) |
| `make compose-tls-https` | Start with forced HTTPS (HTTP redirects to HTTPS) |
| `make compose-tls-down` | Stop TLS-enabled stack |
| `make compose-tls-logs` | Tail logs from TLS services |
| `make compose-tls-ps` | Show TLS stack status |

### Forcing HTTPS Redirect

To redirect all HTTP traffic to HTTPS (recommended for production):

```bash
# Option 1: Use the convenience command
make compose-tls-https

# Option 2: Set environment variable
NGINX_FORCE_HTTPS=true make compose-tls
```

When enabled, requests to `http://localhost:8080` automatically redirect to `https://localhost:8443`.

### Combining with Other Profiles

The TLS profile works alongside other Docker Compose profiles:

```bash
# TLS + Monitoring (Prometheus, Grafana, etc.)
docker compose --profile tls --profile monitoring up -d --scale nginx=0

# TLS + Benchmark servers
docker compose --profile tls --profile benchmark up -d --scale nginx=0
```

!!! note "Scaling nginx to 0"
    When using `--profile tls`, add `--scale nginx=0` to prevent the default nginx from conflicting with `nginx_tls` on port 8080.

### Verifying TLS

```bash
# Test HTTP endpoint
curl http://localhost:8080/health

# Test HTTPS endpoint (skip cert verification for self-signed)
curl -sk https://localhost:8443/health

# Check TLS version
openssl s_client -connect localhost:8443 -brief 2>&1 | head -5
```

Expected output:
```
{"status":"healthy"}
```

### Certificate Details

Auto-generated certificates include:

- **Validity:** 365 days
- **Key size:** RSA 4096-bit
- **Subject Alternative Names:** `localhost`, `gateway`, `nginx`, `127.0.0.1`
- **Protocols:** TLS 1.2 and TLS 1.3

---

## Overview

The MCP Gateway supports TLS/SSL encryption at multiple layers:

1. **Gateway TLS** - Direct HTTPS connections to the gateway (port 4444)
2. **Nginx Frontend TLS** - HTTPS connections from clients to nginx (port 8443)
3. **Nginx Backend TLS** - HTTPS connections from nginx to the gateway backend

## Architecture Options

### Option 1: Gateway TLS Only (Simplest)
```
Client -> HTTPS (self-signed) -> Gateway (port 4444)
```
Best for: Development, testing, internal networks

### Option 2: Nginx SSL Termination (Recommended)
```
Client -> HTTPS (trusted cert) -> Nginx (port 8443) -> HTTP -> Gateway
```
Best for: Production with trusted certificates, load balancing

### Option 3: End-to-End TLS (Most Secure)
```
Client -> HTTPS (trusted cert) -> Nginx (port 8443) -> HTTPS (self-signed) -> Gateway
```
Best for: Zero-trust networks, defense in depth

This guide focuses on **Option 3** (end-to-end TLS).

## Prerequisites

- Docker and Docker Compose installed
- OpenSSL installed (for certificate generation)
- Basic understanding of TLS/SSL concepts

## Step 1: Generate SSL Certificates

### Generate Self-Signed Certificates

For development and testing, generate self-signed certificates:

```bash
# Navigate to project root
cd /path/to/mcp-context-forge

# Generate certificates without passphrase (recommended for automated services)
make certs

# Or with passphrase protection (for gateway only - see note below)
make certs-passphrase
```

This creates:

- `certs/cert.pem` - SSL certificate
- `certs/key.pem` - Unencrypted private key
- `certs/key-encrypted.pem` - Passphrase-protected private key (if using make certs-passphrase)

### Understanding Passphrase-Protected Keys

**Important Security Note**: Passphrase-protected keys are designed for **interactive systems** where a human enters the passphrase at startup. In automated/containerized environments, they provide **minimal security benefit** because:

- The passphrase must be stored alongside the key (in environment variables or files)
- Any process that can read the key can also read the passphrase
- They only protect keys "at rest" when the service is stopped

**When passphrase protection helps:**

- The gateway (Gunicorn/Granian) can decrypt keys programmatically from environment variables
- Adds marginal protection if an attacker gets read-only filesystem access but not environment access
- Useful for compliance requirements that mandate encrypted keys at rest

**Recommended approach:**

- **Development/Testing**: Use unencrypted keys (`make certs`)
- **Production**: Use proper secrets management (see Security Best Practices section)

### Set Passphrase in Environment (Optional)

If using passphrase-protected keys for the gateway:

```bash
# Add to .env file
KEY_FILE_PASSWORD=your-secure-passphrase
```

### For Production: Use Trusted Certificates

For production deployments, obtain certificates from a trusted Certificate Authority (CA):

- **Let's Encrypt** - Free automated certificates
- **Commercial CA** - DigiCert, GlobalSign, etc.
- **Internal CA** - For enterprise deployments

Place your certificates in the `certs/` directory:
```bash
certs/
├── cert.pem          # Your certificate chain
├── key.pem           # Unencrypted key (for nginx)
└── key-encrypted.pem # Encrypted key (for gateway)
```

## Step 2: Configure Gateway TLS

### Environment Variables

Edit `docker-compose.yml` gateway service environment section:

```yaml
gateway:
  environment:
    # Enable SSL
    - SSL=true
    - CERT_FILE=/app/certs/cert.pem
    - KEY_FILE=/app/certs/key-encrypted.pem
    - KEY_FILE_PASSWORD=${KEY_FILE_PASSWORD}  # From .env file
```

### Mount Certificates

Ensure certificates are mounted in the gateway container:

```yaml
gateway:
  volumes:
    - ./certs:/app/certs:ro   # Read-only mount
```

### HTTP Server Selection

The gateway supports two HTTP servers with different TLS implementations:

#### Gunicorn (Default)
```yaml
environment:
  - HTTP_SERVER=gunicorn
```

Gunicorn uses a custom Python SSL key manager that:

- Decrypts passphrase-protected keys at startup
- Creates temporary unencrypted key files
- Supports all SSL/TLS configurations

#### Granian (Rust-based)
```yaml
environment:
  - HTTP_SERVER=granian
```

Granian has native Rust TLS support:

- Supports passphrase-protected keys via `--ssl-keyfile-password`
- Better performance (Rust + Tokio)
- Native HTTP/2 support

Both servers work identically from a client perspective.

### Update Healthcheck

For HTTPS gateway, update the healthcheck to skip SSL verification for self-signed certificates:

```yaml
gateway:
  healthcheck:
    test: ["CMD", "curl", "-fk", "https://localhost:4444/health"]
    interval: 30s
    timeout: 10s
    retries: 5
    start_period: 30s
```

### Expose Gateway Port (Optional)

To access the gateway directly via HTTPS:

```yaml
gateway:
  ports:
    - "4444:4444"  # Expose HTTPS port
```

## Step 3: Configure Nginx TLS

### Frontend TLS (Client → Nginx)

Edit `infra/nginx/nginx.conf` to add HTTPS listeners:

```nginx
server {
    # HTTP listener (port 80)
    listen 80 backlog=4096 reuseport;
    listen [::]:80 backlog=4096 reuseport;

    # HTTPS listener (port 443)
    listen 443 ssl backlog=4096 reuseport;
    listen [::]:443 ssl backlog=4096 reuseport;

    # SSL certificate configuration
    ssl_certificate /app/certs/cert.pem;
    ssl_certificate_key /app/certs/key.pem;  # Use unencrypted key

    # SSL protocols and ciphers
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers HIGH:!aNULL:!MD5;
    ssl_prefer_server_ciphers on;

    # SSL session caching for performance
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;

    server_name localhost;

    # ... rest of configuration
}
```

**Note on Nginx and Key Encryption**: While nginx supports passphrase-protected keys via `ssl_password_file`, this requires storing the passphrase in a plaintext file, which provides no security benefit over using an unencrypted key with proper filesystem permissions. For automated services, use unencrypted keys and protect them via:

- Filesystem permissions (mode 640 with group 0 for containers)
- Read-only volume mounts
- Secrets management systems (production)

### Creating Unencrypted Key from Encrypted Key

If you have a passphrase-protected key and need an unencrypted version for nginx:

```bash
# Using make command (recommended - handles permissions automatically)
make certs-remove-passphrase

# Or manually with openssl
cd certs
openssl rsa -in key-encrypted.pem -out key.pem -passin pass:YOUR_PASSWORD
chmod 640 key.pem
sudo chgrp 0 key.pem  # Set group to 0 for container access
```

The `make certs-remove-passphrase` command will:

1. Prompt for your passphrase to decrypt the key
2. Create `certs/key.pem` with 640 permissions
3. Automatically set group to 0 using sudo (you'll be prompted for password)

### Backend TLS (Nginx → Gateway)

Configure nginx to connect to the gateway via HTTPS:

```nginx
# Upstream configuration (before server block)
upstream gateway_backend {
    least_conn;
    server gateway:4444 max_fails=0;

    keepalive 512;
    keepalive_requests 100000;
    keepalive_timeout 60s;
}

# SSL Backend Configuration
proxy_ssl_protocols TLSv1.2 TLSv1.3;
proxy_ssl_verify off;  # Disable for self-signed certs
# Or enable verification with trusted CA:
# proxy_ssl_verify on;
# proxy_ssl_trusted_certificate /app/certs/ca-bundle.pem;
proxy_ssl_session_reuse on;
```

Update all `proxy_pass` directives to use HTTPS:

```nginx
location / {
    proxy_pass https://gateway_backend;  # Changed from http:// to https://
    # ... other proxy settings
}
```

### Mount Certificates in Nginx

In `docker-compose.yml`, mount certificates and config:

```yaml
nginx:
  volumes:
    - nginx_cache:/var/cache/nginx
    - ./infra/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
    - ./certs:/app/certs:ro  # Mount certificates
```

### Expose Nginx HTTPS Port

```yaml
nginx:
  ports:
    - "8080:80"    # HTTP
    - "8443:443"   # HTTPS
```

### Update Nginx Dockerfile

Edit `infra/nginx/Dockerfile` to expose port 443:

```dockerfile
# Expose HTTP and HTTPS ports
EXPOSE 80 443
```

## Step 4: Deploy with TLS

### Build and Start Services

Use the standard make commands to build and deploy:

```bash
# Build production container image
make docker-prod

# Start all services (validates compose file and starts stack)
make compose-up

# Check service status
docker compose ps
```

**What these commands do:**

- `make docker-prod` - Builds the gateway container image using `Containerfile.lite`
- `make compose-up` - Validates `docker-compose.yml` and starts all services in detached mode

These commands automatically handle image tagging and validation.

### Verify Gateway Health

```bash
# Direct HTTPS to gateway (skip SSL verification for self-signed)
curl -fk https://localhost:4444/health

# Expected output: {"status":"healthy"}
```

### Verify Nginx Health

```bash
# HTTP via nginx
curl -f http://localhost:8080/health

# HTTPS via nginx (skip SSL verification for self-signed)
curl -fk https://localhost:8443/health

# Expected output: {"status":"healthy"}
```

## Step 5: Testing

### Test Direct Gateway Access

```bash
# HTTPS to gateway
curl -fkv https://localhost:4444/health

# Check certificate details
openssl s_client -connect localhost:4444 -servername localhost < /dev/null
```

### Test Nginx Proxy

```bash
# HTTP to nginx (proxies to HTTPS gateway)
curl -fv http://localhost:8080/health

# HTTPS to nginx (proxies to HTTPS gateway)
curl -fkv https://localhost:8443/health
```

### Test with Browser

1. **Direct Gateway**: `https://localhost:4444/health`

   - Accept security warning for self-signed certificate

2. **Nginx HTTP**: `http://localhost:8080/health`

   - No security warning (plain HTTP)

3. **Nginx HTTPS**: `https://localhost:8443/health`

   - Accept security warning for self-signed certificate

## Troubleshooting

### TLS Handshake Errors

**Symptom**: Gateway logs show TLS handshake failures:
```
[INFO] TCP handshake failed with error: TlsAcceptError {
  error: Custom { kind: InvalidData, error: InvalidMessage(InvalidContentType) },
  peer_addr: 172.18.0.X:XXXXX
}
```

**Cause**: Nginx's keepalive connection pool is trying to reuse old HTTP connections to the now-HTTPS gateway.

**Solution**: Restart nginx to clear the connection pool:
```bash
docker compose restart nginx
```

### 502 Bad Gateway from Nginx

**Symptom**: Nginx returns 502 errors when proxying to gateway.

**Possible Causes**:

1. **Nginx using HTTP to connect to HTTPS gateway**

   - Check: `proxy_pass` should be `https://gateway_backend`
   - Fix: Update nginx.conf and restart: `docker compose restart nginx`

2. **SSL certificate hostname mismatch**

   - Check nginx error logs: `docker compose logs nginx`
   - Error: `upstream SSL certificate does not match "gateway_backend"`
   - Fix: Set `proxy_ssl_verify off;` in nginx.conf for self-signed certs

3. **Missing certificates in nginx container**

   - Check: Verify volume mount in docker-compose.yml
   - Fix: Add `- ./certs:/app/certs:ro` to nginx volumes

### Gateway Healthcheck Failing

**Symptom**: `docker compose ps` shows gateway as "unhealthy"

**Cause**: Healthcheck using HTTP to check HTTPS endpoint, or not skipping SSL verification.

**Fix**: Update healthcheck in docker-compose.yml:
```yaml
gateway:
  healthcheck:
    test: ["CMD", "curl", "-fk", "https://localhost:4444/health"]
```

The `-k` flag skips SSL certificate verification for self-signed certificates.

### Passphrase Errors with Gunicorn

**Symptom**: Gunicorn fails to start with SSL key errors.

**Cause**: Missing or incorrect `KEY_FILE_PASSWORD` environment variable.

**Fix**:

1. Verify `.env` file contains: `KEY_FILE_PASSWORD=your-passphrase`
2. Verify docker-compose.yml references it: `- KEY_FILE_PASSWORD=${KEY_FILE_PASSWORD}`
3. Restart gateway: `docker compose restart gateway`

### Granian TLS Errors

**Symptom**: Granian fails to start or shows TLS initialization errors.

**Cause**: Passphrase not passed correctly to Granian.

**Fix**: Granian expects the passphrase via environment variable. Ensure `KEY_FILE_PASSWORD` is set in `.env` and referenced in docker-compose.yml.

### Connection Refused

**Symptom**: `curl: (7) Failed to connect to localhost port 4444: Connection refused`

**Cause**: Gateway port not exposed or service not started.

**Fix**:

1. Check service is running: `docker compose ps gateway`
2. Check port mapping: Should show `0.0.0.0:4444->4444/tcp`
3. Uncomment ports in docker-compose.yml if commented

### Self-Signed Certificate Warnings

**Symptom**: Browser shows "Your connection is not private" warning.

**Expected Behavior**: This is normal for self-signed certificates in development.

**Solutions**:

- **Development**: Click "Advanced" → "Proceed to localhost (unsafe)"
- **CI/CD**: Use `curl -k` flag to skip verification
- **Production**: Use trusted certificates from a CA

## Clean Network and Reset

If you encounter persistent connection errors after changing TLS configuration:

### Full Reset Procedure

```bash
# Stop all services
docker compose down

# Remove network (clears all connection pools)
docker network rm mcp-context-forge_mcpnet

# Recreate and start services
docker compose up -d

# Verify health
docker compose ps
curl -fk https://localhost:4444/health
curl -f http://localhost:8080/health
curl -fk https://localhost:8443/health
```

### Selective Service Restart

If only nginx has stale connections:

```bash
# Stop and start (recreates container)
docker compose stop nginx
docker compose start nginx
```

If gateway needs fresh connections:

```bash
docker compose restart gateway
```

## Security Best Practices

### Development and Testing

1. **Protect keys with filesystem permissions**

   The `make certs` and `make certs-passphrase` commands automatically set correct permissions:

   ```bash
   # Permissions set automatically by make commands:
   chmod 644 certs/cert.pem          # Public certificate - world-readable is OK
   chmod 640 certs/key.pem           # Private key - owner+group only, no world access
   sudo chgrp 0 certs/key.pem        # Set group to 0 for container access
   ```

   **Why group 0 and 640?**
   - Container runs as UID 1001, GID 0 (see Containerfile.lite line 236, 271)
   - Host files are owned by your UID (e.g., 1000), not container UID (1001)
   - By setting group to 0 (root group) and permissions to 640:

     - Owner (your UID): Read/write access ✅
     - Group 0: Read access ✅ ← **Container (1001:0) accesses via this**
     - Others: No access ✅

   - More secure than 644 (no world access)

   **Sudo requirement**: The make commands use `sudo chgrp 0` to set the group. You'll be prompted for your password once. If sudo is not available, you'll see a warning but cert generation will still succeed (you can set the group manually later).

2. **Never commit secrets to git**

   - Certificate files are in `.gitignore`
   - Never commit `.env` files with passwords/passphrases
   - Use `.env.example` as a template without real secrets

3. **Use read-only volume mounts**
   ```yaml
   volumes:
     - ./certs:/app/certs:ro  # :ro = read-only
   ```

4. **Rotate certificates regularly** (every 90 days minimum, even for self-signed)
5. **Passphrase protection consideration**

   - Passphrase-protected keys provide minimal benefit in automated environments
   - Only protects keys when service is stopped
   - Consider for compliance requirements or gateway-only deployments

### Production

1. **Use trusted CA certificates** (Let's Encrypt, commercial CA, internal PKI)

   - Let's Encrypt is free and automated
   - Commercial CAs for enterprise support
   - Internal CA for private networks

2. **Implement proper secrets management**

   - **Kubernetes**: Use Secrets with RBAC
     ```yaml
     apiVersion: v1
     kind: Secret
     metadata:
       name: tls-secret
     type: kubernetes.io/tls
     data:
       tls.crt: <base64-encoded-cert>
       tls.key: <base64-encoded-key>
     ```

   - **Docker Swarm**: Use Docker Secrets
     ```bash
     docker secret create tls_cert cert.pem
     docker secret create tls_key key.pem
     ```

   - **HashiCorp Vault**: Store and inject secrets at runtime
   - **Cloud KMS**: AWS KMS, Google Cloud KMS, Azure Key Vault

3. **Enable certificate validation** for backend connections
   ```nginx
   proxy_ssl_verify on;
   proxy_ssl_trusted_certificate /etc/ssl/certs/ca-bundle.crt;
   ```

4. **Use strong TLS protocols** (TLSv1.2 and TLSv1.3 only)

   - Disable SSLv3, TLS 1.0, TLS 1.1
   - Use modern cipher suites

5. **Implement certificate rotation automation**

   - Let's Encrypt with certbot (auto-renewal)
   - cert-manager for Kubernetes
   - Custom rotation scripts

6. **Monitor certificate expiration** (30 days warning minimum)

   - Prometheus + alertmanager
   - Cloud monitoring services
   - Custom monitoring scripts

7. **Use HSTS headers** to enforce HTTPS
   ```nginx
   add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
   ```

8. **Consider certificate pinning** for highly sensitive deployments

   - Public Key Pinning Extension (HPKP) - deprecated
   - Certificate Transparency monitoring
   - Application-level pinning

9. **Use Hardware Security Modules (HSM)** for high-security environments

   - Cloud HSM services (AWS CloudHSM, Azure Dedicated HSM)
   - On-premises HSMs
   - PKCS#11 integration with nginx/gateway

### Key Security Reality

**Important**: For automated services (containers, VMs, cloud), key security relies on:

1. **Access control** - Who can read the key file or secret
2. **Filesystem permissions** - Unix permissions with proper group ownership

   - Containers: 640 with group 0 (owner+group, no world access)
   - Container user (UID 1001, GID 0) accesses via group membership

3. **Secrets management** - Proper injection and rotation
4. **Network isolation** - Limit exposure of TLS endpoints
5. **Audit logging** - Track secret access

**Passphrase protection does NOT add security** when the passphrase must be stored alongside the key. The real security boundary is access control to the secret store (filesystem, Kubernetes API, Vault, etc.).

### Certificate Management

```bash
# Check certificate expiration
openssl x509 -in certs/cert.pem -noout -dates

# Verify certificate matches private key
openssl x509 -noout -modulus -in certs/cert.pem | openssl md5
openssl rsa -noout -modulus -in certs/key.pem | openssl md5
# Output should match

# View certificate details
openssl x509 -in certs/cert.pem -text -noout
```

## Configuration Examples

### Complete docker-compose.yml TLS Configuration

```yaml
services:
  gateway:
    image: mcpgateway/mcpgateway:latest
    ports:
      - "4444:4444"
    environment:
      # TLS Configuration
      - SSL=true
      - CERT_FILE=/app/certs/cert.pem
      - KEY_FILE=/app/certs/key-encrypted.pem
      - KEY_FILE_PASSWORD=${KEY_FILE_PASSWORD}

      # HTTP Server (gunicorn or granian)
      - HTTP_SERVER=granian

      # Other settings...
      - HOST=0.0.0.0
      - PORT=4444
    volumes:
      - ./certs:/app/certs:ro
    healthcheck:
      test: ["CMD", "curl", "-fk", "https://localhost:4444/health"]
      interval: 30s
      timeout: 10s
      retries: 5
      start_period: 30s

  nginx:
    image: mcpgateway/nginx-cache:latest
    ports:
      - "8080:80"    # HTTP
      - "8443:443"   # HTTPS
    volumes:
      - ./infra/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
      - ./certs:/app/certs:ro
      - nginx_cache:/var/cache/nginx
    depends_on:
      gateway:
        condition: service_healthy

volumes:
  nginx_cache:
```

### Complete nginx.conf TLS Configuration

```nginx
upstream gateway_backend {
    least_conn;
    server gateway:4444 max_fails=0;
    keepalive 512;
    keepalive_requests 100000;
    keepalive_timeout 60s;
}

# Backend SSL configuration
proxy_ssl_protocols TLSv1.2 TLSv1.3;
proxy_ssl_verify off;
proxy_ssl_session_reuse on;

server {
    # HTTP listener
    listen 80 backlog=4096 reuseport;
    listen [::]:80 backlog=4096 reuseport;

    # HTTPS listener
    listen 443 ssl backlog=4096 reuseport;
    listen [::]:443 ssl backlog=4096 reuseport;

    # SSL certificates
    ssl_certificate /app/certs/cert.pem;
    ssl_certificate_key /app/certs/key.pem;

    # SSL configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers HIGH:!aNULL:!MD5;
    ssl_prefer_server_ciphers on;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;

    server_name localhost;

    location / {
        proxy_pass https://gateway_backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}
```

## Additional Resources

- [OpenSSL Documentation](https://www.openssl.org/docs/)
- [Let's Encrypt](https://letsencrypt.org/)
- [Nginx SSL Module](https://nginx.org/en/docs/http/ngx_http_ssl_module.html)
- [Mozilla SSL Configuration Generator](https://ssl-config.mozilla.org/)

## Related Documentation

- [Docker Compose Deployment](compose.md)
- [Kubernetes TLS Configuration](kubernetes.md)
- [Security Best Practices](../manage/securing.md)
- [Proxy Authentication](proxy-auth.md)