Judge0 CE certificates.
One DNS setup. Easier renewals.

Why put Judge0 CE behind this certificate workflow?

API to compile and run source code.

For a private Judge0 CE deployment, maintaining public port-80 validation just for renewal can add routing work. A native DNS-01 client can avoid that listener but may need a supported DNS-provider integration and its credentials. SimpleACME is our preferred option when you want a permanent challenge delegation and one renewal workflow across different services.

Keep application access controls, backups and network policy in place. This guide adds an HTTPS endpoint to an existing service; it does not install Judge0 CE, provision its database, or make an unauthenticated application safe to expose.

Configure Judge0 CE step by step

1. Check the existing Judge0 CE endpoint

   Keep Judge0 CE installed using its upstream deployment instructions. The linked source includes an example listener or published HTTP endpoint on port 2358. Confirm your own private endpoint from the gateway host before copying the router. The port is a documented example, not a universal default for every version or installation.

2. Choose the HTTPS hostname

   Use a dedicated hostname such as judge0-ce.example.com at the domain root. Make it resolve to your gateway for your clients, using private DNS if appropriate. Keep the application backend reachable only by the gateway and preserve the application’s authentication.

3. Prepare the domain and permanent CNAME

   Add the intended hostname in SimpleACME. A single-domain demo can prepare DNS before payment and cannot send TXT updates. Copy the exact _acme-challenge owner and assigned CNAME target from the domain card into your authoritative public DNS, then use Check CNAME.

4. Connect the certificate renewal client

   Activate the matching paid domain, then configure Traefik’s simpleacme certificate resolver using the subscriber Traefik guide. Preseed the ACME-DNS account file with that domain’s existing credentials. The public /register route is closed; the client must reuse its registration. Use staging first.

5. Align Judge0 CE with the HTTPS origin

   Use judge0-ce.example.com as the public origin for this Judge0 CE deployment. If your installed version exposes a public/base URL, allowed-host, callback or trusted-proxy setting, configure it using the linked project instructions. Trust forwarded headers only from the actual gateway. The gateway fragment below does not change Judge0 CE configuration or install the application.

6. Add the Judge0 CE HTTPS router

   Merge the named router and service below into the file watched by your existing Traefik file provider. Replace the example hostname and documentation address 192.0.2.10 with the real hostname and private backend IP; use your actual published HTTP port. Keep existing routers and services.

7. Verify the complete client journey

   After staging succeeds, select the production certificate authority in your resolver. Open https://judge0-ce.example.com/ from an authorized client and check hostname, certificate chain and expiry. Test Judge0 CE login, uploads, WebSockets, API requests and callbacks that your deployment uses. This route covers HTTP traffic; SSH, SMTP, media, discovery and other transports require their own configuration.

8. Keep renewal and monitoring enabled

   Leave the challenge CNAME in place and keep Traefik running with persistent ACME storage and current paid domain access. Monitor DNS challenge activity in SimpleACME and the actual served certificate independently. A TXT change is an authorization event, not proof that Judge0 CE renewed or installed a certificate.

Check the private Judge0 CE backend

curl --head --connect-timeout 5 http://192.0.2.10:2358/

Run from the gateway network after replacing the documentation IP and port with your actual Judge0 CE endpoint. Authentication responses and redirects can be expected; do not disable authentication to make a test return 200.

Judge0 CE Traefik router example

# Merge these entries into the file watched by your existing Traefik file provider.
# Requires the simpleacme resolver and your pre-registered ACME-DNS account.
# Replace the hostname and 192.0.2.10 with your real hostname and private backend IP.
http:
  routers:
    judge0-ce:
      rule: 'Host(`judge0-ce.example.com`)'
      entryPoints: [websecure]
      service: judge0-ce
      tls:
        certResolver: simpleacme
  services:
    judge0-ce:
      loadBalancer:
        passHostHeader: true
        servers:
          - url: 'http://192.0.2.10:2358'

The fragment assumes a websecure entrypoint and a simpleacme resolver already configured by the subscriber Traefik guide. Merge entries into the watched dynamic file rather than overwriting other applications. Replace the sample hostname with the exact paid hostname; keep credentials and certificate storage private.

Verify the trusted HTTPS endpoint

curl --head --resolve judge0-ce.example.com:443:192.0.2.20 https://judge0-ce.example.com/

Replace the second documentation address with the gateway IP and use this after a trusted production certificate is installed. Staging certificates are intentionally untrusted. Do not hide trust or hostname errors when validating the production setup.

Compare ACME validation for Judge0 CE

Our recommendation for Judge0 CE: choose SimpleACME when private-service validation, fewer DNS credentials and a reusable gateway matter most. HTTP-01 remains a valid choice for an already-public responder; narrowly scoped native DNS automation can also suit an existing deployment.

Client guides and application sources

Traefik full configuration · Certbot hooks · Certbot Docker · win-acme PowerShell · AI setup assistant. Complete subscriber assets require active paid access. For native certificate imports, use the application’s deployment documentation and a suitable certificate-deployment hook.

• Judge0 CE project website ↗
• Judge0 CE endpoint and deployment source ↗
• Judge0 CE configuration reference ↗
• Traefik ACME DNS challenge reference ↗

Source review: 2026-11-08. Product versions and deployment packaging change; verify the actual listener and application settings before applying the example.

Software summary from Awesome-Selfhosted’s Judge0 CE record, licensed CC BY-SA 3.0. Gateway instructions and illustration by SimpleACME. No vendor affiliation is claimed.