TLS Certificates
Atrium requires HTTPS. The Traefik reverse proxy handles TLS termination and supports two certificate sources.
Option A: Let's Encrypt (default)
By default, Traefik obtains a free TLS certificate from Let's Encrypt automatically using the HTTP-01 challenge:
- Traefik requests a certificate for your domain.
- Let's Encrypt verifies you control the domain by making an HTTP request to port 80.
- The certificate is issued and stored in
/certs/acme.jsoninside the Traefik container. - Certificates are renewed automatically before expiry (Let's Encrypt certificates are valid for 90 days).
Requirements:
- Port 80 must be accessible from the internet (Let's Encrypt needs to reach it).
- The domain's DNS must point to the server's IP.
DNS-01 challenge (alternative)
If port 80 is blocked, Traefik can use the DNS-01 challenge instead. This verifies domain ownership via a DNS TXT record, which doesn't require inbound port 80 access.
To use DNS-01 with Cloudflare:
- Set
CF_DNS_API_TOKENin your.envfile with a Cloudflare API token (Zone → DNS → Edit permissions). - Update the Traefik configuration to use the
dnsChallengeresolver instead ofhttpChallenge.
Other DNS providers are supported via Traefik's ACME provider plugins. See Traefik's ACME documentation for the full list.
Option B: Custom certificates
If you have your own TLS certificates (e.g., from an internal CA or a purchased certificate), you can configure Traefik to use them directly:
- Place your certificate and private key on the server (e.g.,
/opt/atrium/certs/). - Update the Traefik configuration to use file-based certificates instead of ACME.
- Mount the certificate directory into the Traefik container.
Ensure you handle certificate renewal yourself — Traefik won't renew custom certificates automatically.
Self-signed certificates (development only)
For testing or development, you can use self-signed certificates. Browsers will show a security warning, but the system will function normally. Do not use self-signed certificates in production — pre-registration email links and kiosk PWA installations require a trusted certificate.