Let’s Encrypt Integration

Let’s Encrypt is a certificate authority that provides free SSL/TLS certificates via an automated process. Their certificates are accepted by most of today’s browsers.

APPUiO provides integration with Let’s Encrypt to automatically create, sign, install and renew certificates for your domains running on APPUiO.

To create a certificate for one of your domains follow these steps:

  1. If you haven’t already done so create a route for the fully qualified domain name (FQDN), e.g. www.example.org, your application should run under. If using the web console, make sure you do not tick the “Secure Route” box when creating the route.

  2. Add a CNAME record (important!) for the FQDN to the DNS of your domain pointing to cname.appuioapp.ch. E.g. in BIND: www  IN  CNAME  cname.appuioapp.ch. (the trailing dot is required)

  3. Annotate your route:

    oc -n MYNAMESPACE annotate route ROUTE kubernetes.io/tls-acme=true
    

Warning

Always create a route before pointing a DNS entry to APPUiO and always remove the corresponding DNS entry before deleting a route for a domain of yours. Otherwise someone else could potentially create a route and a Let’s Encrypt certificate for your domain.

Note

  1. APPUiO automatically renews certificates a few days before they expire.
  2. Let’s Encrypt can only create domain validated certificates, i.e. it’s not possible to add an organization name to a Let’s Encrypt certificate.

If you don’t specify a host value in your Route object APPUiO will use its default domain appuioapp.ch for your convenience to create a working subdomain for your application.

Creating certificates for this domain is neither needed nor supported as APPUiO already has a wildcard certificate installed for *.appuioapp.ch. Without this wildcard certificate we would hit the Let’s Encrypt rate limits on the appuioapp.ch domain sooner or later.

Implementation details

APPUiO uses the OpenShift ACME controller to provide the Let’s Encrypt integration.

The certificates are stored in the target Route object in the corresponding project. If you require the certificate to be stored as a Secret, to mount it into your Pod for SSL Passthrough, add the acme.openshift.io/secret-name annotation, e.g.

oc -n MYNAMESPACE annotate route ROUTE acme.openshift.io/secret-name=MYSECRETNAME