Secure with HTTPS

To enable HTTPS on your BinderHub you can setup an ingress proxy and configure it to serve both, the Binder and JupyterHub interface, using TLS. You can either manually provide TLS certificates or use Let’s Encrypt to automatically get signed certificates.

Setup IP & domain

  1. Get a static IP(v4) address that you will assign to your ingress proxy later. For example, on Google Cloud this can be done using gcloud compute addresses create <alias-name-for-ip> --region <region> and retrieve the assigned IP using gcloud compute addresses list.

  2. Buy a domain name from a registrar. Pick whichever one you want.

  3. Set A records to your above retrieved external IP, one for Binder and one for JupyterHub. We need two distinct subdomains for the routing to the two different services as they will be served by the same ingress proxy. We suggest you use hub.binder. for JupyterHub and binder. for your BinderHub. Once you are done your BinderHub will be available at https://binder..

  4. Wait some minutes for the DNS A records to propagate.

cert-manager for automatic TLS certificate provisioning

To automatically generate TLS certificates and sign them using Let’s Encrypt, we utilise cert-manager. Installation is done by using the following command:

kubectl apply -f https://github.com/jetstack/cert-manager/releases/download/v0.11.0/cert-manager.yaml

For installations of Kubernetes v1.15 or below, you also need to supply --validate=false to the above command. For more detail on this, see the Getting Started guide.

We then need to create an issuer that will contact Let’s Encrypt for signing our certificates. Use the following template to create a new file binderhub-issuer.yaml and instantiate it using kubectl apply -f binderhub-issuer.yaml.

apiVersion: cert-manager.io/v1alpha2
kind: Issuer
metadata:
  name: letsencrypt-production
  namespace: <same-namespace-as-binderhub>
spec:
  acme:
    # You must replace this email address with your own.
    # Let's Encrypt will use this to contact you about expiring
    # certificates, and issues related to your account.
    email: <your-contact-mail>
    server: https://acme-v02.api.letsencrypt.org/directory
    privateKeySecretRef:
      # Secret resource used to store the account's private key.
      name: letsencrypt-production
    solvers:
    - http01:
        ingress:
          class: nginx

See the documentation for more details on configuring the issuer.

Ingress proxy using nginx

We will use the nginx ingress controller to proxy the TLS connection to our BinderHub setup. This will run using the static IP we have acquired before. We therefore create a new configuration file nginx-ingress.yaml:

controller:
  service:
    loadBalancerIP: <STATIC-IP>

Afterwards we install the ingress proxy using helm install stable/nginx-ingress --name binderhub-proxy --namespace <same-namespace-as-binderhub> -f nginx-ingress.yaml. Then wait until it is ready and showing the correct IP when looking at the output of kubectl --namespace <same-namespace-as-binderhub> get services binderhub-proxy-nginx-ingress-controller.

Adjust BinderHub config to serve via HTTPS

With the static IP, DNS records and ingress proxy setup, we can now change our BinderHub configuration to serve traffic via HTTPS. Therefore adjust your config.yaml with the following sections and apply it using helm upgrade ....

config:
  BinderHub:
    hub_url: https://<jupyterhub-URL>

jupyterhub:
  ingress:
    enabled: true
    hosts:
      - <jupyterhub-URL>
    annotations:
      kubernetes.io/ingress.class: nginx
      kubernetes.io/tls-acme: "true"
      cert-manager.io/issuer: letsencrypt-production
      https:
        enabled: true
        type: nginx
    tls:
       - secretName: <jupyterhub-URL-with-dashes-instead-of-dots>-tls
         hosts:
          - <jupyterhub-URL>

ingress:
  enabled: true
  hosts:
     - <binderhub-URL>
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
    cert-manager.io/issuer: letsencrypt-production
    https:
      enabled: true
      type: nginx
  tls:
    - secretName: <binderhub-URL-with-dashes-instead-of-dots>-tls
      hosts:
        - <binderhub-URL>

Once the helm upgrade ... command has been run, it may take up to 10 minutes until the certificates are issued. You can check their status using kubectl describe certificate --namespace <binderhub-namespace> <binderhub-URL>-tls.