Setting Up Custom Domain

If you prefer to use your own custom domain, this page will guide you through setting this up in minutes.

Zero Trust HTTPS: Custom Domain Setup for dstack Apps

This is a solution for setting up custom domains with automatic SSL certificate management for dstack applications using Cloudflare DNS and Let's Encrypt. With this implementation, Phala enables the world's first Zero Trust HTTPS solution for your domain and apps running in a Confidential VM on Phala Cloud in one-click.

Overview

This project enables you to run dstack applications with your own custom domain, complete with:

• Automatic SSL certificate provisioning and renewal via Let's Encrypt

• Cloudflare DNS configuration for CNAME, TXT, and CAA records

• Nginx reverse proxy to route traffic to your application

• Certificate evidence generation for verification

How It Works

The dstack-ingress system provides a seamless way to set up custom domains for dstack applications with automatic SSL certificate management. Here's how it works:

1. Initial Setup:

   • When first deployed, the container automatically obtains SSL certificates from Let's Encrypt using DNS validation

   • It configures Cloudflare DNS by creating necessary CNAME, TXT, and optional CAA records

   • Nginx is configured to use the obtained certificates and proxy requests to your application

2. DNS Configuration:

   • A CNAME record is created to point your custom domain to the dstack gateway domain

   • A TXT record is added with application identification information to help dstack-gateway to route traffic to your application

   • If enabled, CAA records are set to restrict which Certificate Authorities can issue certificates for your domain

3. Certificate Management:

   • Select the Create Token button as shown below

   • SSL certificates are automatically obtained during initial setup

   • A scheduled task runs twice daily to check for certificate renewal

   • When certificates are renewed, Nginx is automatically reloaded to use the new certificates

4. Evidence Generation:

   • The system generates evidence files for verification purposes

   • These include the ACME account information and certificate data

   • Evidence files are accessible through a dedicated endpoint

Prerequisites

• Host your domain on Cloudflare and have access to the Cloudflare account with API token

Create Cloudflare API Token

If you have not generated an API Token for your custom domain management then follow these steps:

Create API Token

1️⃣ Go to your Cloudflare Dashboard

In your dashboard, select the domain you'd like to use and find the option to Get Your API Token

2️⃣ Create API Token

Select the Create Token button as shown below

3️⃣ Select a Template

The next page will have several templates. Select the template to Edit zone DNS as shown below

4️⃣ Finalize API Token Creation

Next select your domain in the Zone Resources section then click Continue to summary button as shown below

Congrats! You've now created your API Token to use for your environment variable.

Deployment

For more details, checkout the github repository for the dstack-ingress dstack examples.

First you will go to your Phala Cloud Dashboard and deploy a new CVM. Select docker-compose.yml option for deployment then take the past the docker compose file below into the Advanced tab of the CVM configration page.

services:
  dstack-ingress:
    image: kvin/dstack-ingress@sha256:8dfc3536d1bd0be0cb938140aeff77532d35514ae580d8bec87d3d5a26a21470
    ports:
      - "443:443"
    environment:
      - CLOUDFLARE_API_TOKEN=${CLOUDFLARE_API_TOKEN}
      - DOMAIN=${DOMAIN}
      - GATEWAY_DOMAIN=${GATEWAY_DOMAIN}
      - CERTBOT_EMAIL=${CERTBOT_EMAIL}
      - SET_CAA=true
      - TARGET_ENDPOINT=http://app:80
    volumes:
      - /var/run/tappd.sock:/var/run/tappd.sock
      - cert-data:/etc/letsencrypt
    restart: unless-stopped
  app:
    image: nginx  # Replace with your application image
    restart: unless-stopped
volumes:
  cert-data:  # Persistent volume for certificates

Explanation of environment variables:

• CLOUDFLARE_API_TOKEN: Your Cloudflare API token

• DOMAIN: Your custom domain

• GATEWAY_DOMAIN: The dstack gateway domain. (e.g. _.dstack-prod5.phala.network for Phala Cloud)

• CERTBOT_EMAIL: Your email address used in Let's Encrypt certificate requests

• TARGET_ENDPOINT: The plain HTTP endpoint of your dstack application

• SET_CAA: Set to true to enable CAA record setup

Deploy to Phala Cloud

If you prefer video content, check the YouTube tutorial here.

Here is how it should look like in the dashboard.

Next you need to grab your Cloudflare API Token for your domain, and fill in your environment variables. For this example, deploy to prod5.

Click Create button and your CVM will deploy in a couple minutes with the custom domain. Here is an example of a custom domain deployed to phala.incipient.ltd.

Domain Attestation and Verification

The dstack-ingress system provides mechanisms to verify and attest that your custom domain endpoint is secure and properly configured. This comprehensive verification approach ensures the integrity and authenticity of your application.

Evidence Collection

When certificates are issued or renewed, the system automatically generates a set of cryptographically linked evidence files:

1. Access Evidence Files:

   • Evidence files are accessible at https://your-domain.com/evidences/

   • Key files include acme-account.json, cert.pem, sha256sum.txt, and quote.json

2. Verification Chain:

   • quote.json contains a TDX quote with the SHA-256 digest of sha256sum.txt embedded in the report_data field

   • sha256sum.txt contains cryptographic checksums of both acme-account.json and cert.pem

   • When the TDX quote is verified, it cryptographically proves the integrity of the entire evidence chain

3. Certificate Authentication:

   • acme-account.json contains the ACME account credentials used to request certificates

   • When combined with the CAA DNS record, this provides evidence that certificates can only be requested from within this specific TEE application

   • cert.pem is the Let's Encrypt certificate currently serving your custom domain

You can check the example of the deployment at phala.incipient.ltd/evidences/.

CAA Record Verification

If you've enabled CAA records (SET_CAA=true), you can verify that only authorized Certificate Authorities can issue certificates for your domain:

dig CAA your-domain.com

The output will display CAA records that restrict certificate issuance exclusively to Let's Encrypt with your specific account URI, providing an additional layer of security.

TLS Certificate Transparency

All Let's Encrypt certificates are logged in public Certificate Transparency (CT) logs, enabling independent verification:

CT Log Verification:

• Visit crt.sh and search for your domain
• Confirm that the certificates match those issued by the dstack-ingress system

• This public logging ensures that all certificates are visible and can be monitored for unauthorized issuance