Fix tls certificate generation in k8s

The "Certificate" objects are no longer required. As a consequence, the
"k8s-ingress-certificates" has become useless and should be removed from
plugins.

CHANGELOG.md

@@ -4,6 +4,7 @@ Note: Breaking changes between versions are indicated by "💥".
 
 ## Unreleased
 
+- [Improvement] Fix tls certificate generation in k8s
 - [Improvement] Upgrade k8s certificate issuer to cert-manager.io/v1alpha2
 - [Feature] Add SCORM XBlock to default openedx docker image
 

docs/k8s.rst

@@ -58,6 +58,19 @@ If you decide to enable HTTPS certificates, you will also have to set ``WEB_PROX
 
 Note that this configuration might conflict with a local installation.
 
+.. warning::
+    On DigitalOcean, there is currently a bug that prevents certificate issuers from successfully fetching TLS certificates from Let's Encrypt. A workaround consists in adding a custom annotation to the "ingress-nginx" service::
+        
+        kubectl -n ingress-nginx patch service ingress-nginx -p \
+            '{"metadata": {"annotations": {"service.beta.kubernetes.io/do-loadbalancer-hostname": "YOURLMSHOSTHERE"}}}'
+    
+    Sources:
+    
+    * https://www.digitalocean.com/community/questions/how-do-i-correct-a-connection-timed-out-error-during-http-01-challenge-propagation-with-cert-manager
+    * https://www.digitalocean.com/community/questions/pod-unable-to-curl-loadbalancer
+    * https://github.com/jetstack/cert-manager/issues/863#issuecomment-567062996
+    * https://github.com/digitalocean/digitalocean-cloud-controller-manager/blob/master/docs/controllers/services/examples/README.md#accessing-pods-over-a-managed-load-balancer-from-inside-the-cluster
+
 S3-like object storage with `MinIO <https://www.minio.io/>`_
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tutor/templates/k8s/ingress.yml

@@ -7,8 +7,8 @@ metadata:
     app.kubernetes.io/name: web
   annotations:
     nginx.ingress.kubernetes.io/proxy-body-size: 1000m
-    {% if ACTIVATE_HTTPS%}cert-manager.io/issuer: letsencrypt
+    {% if ACTIVATE_HTTPS%}kubernetes.io/tls-acme: "true"
-    cert-manager.io/acme-challenge-type: http01{% endif %}
+    cert-manager.io/issuer: letsencrypt{% endif %}
 spec:
   rules:
   {% for host in hosts %}
@@ -42,21 +42,8 @@ spec:
     privateKeySecretRef:
       name: letsencrypt-privatekey
     solvers:
-      - http01:
+      - selector: {}
+        http01:
           ingress:
             class: nginx
----
-apiVersion: cert-manager.io/v1alpha2
-kind: Certificate
-metadata:
-  name: {{ LMS_HOST|replace(".", "-") }}
-spec:
-  secretName: {{ LMS_HOST }}-tls
-  issuerRef:
-    name: letsencrypt
-  commonName: {{ LMS_HOST }}
-  dnsNames:
-  - {{ LMS_HOST }}
-  - {{ CMS_HOST }}
-{{ patch("k8s-ingress-certificates") }}
 {% endif %}