workaround CI installing same config against different schemas

- install an extra 'old' yaml config when installing against an old binderhub version
- this file should only exist during PRs that change the schema, delete immediately after merging

.github/workflows/diff.yml

@@ -37,11 +37,20 @@ jobs:
 
           # NOTE: We change the directory so binderhub the chart name won't be
           #       misunderstood as the local folder name.
+          # validation is disabled, because the config is for a different version!
           cd testing
 
+          old_config="../testing/k8s-binder-k8s-hub/binderhub-chart-config-old.yaml"
+          if [ -f "$old_config" ]; then
+            echo "using old config"
+          else
+            old_config="../testing/k8s-binder-k8s-hub/binderhub-chart-config.yaml"
+          fi
+
           helm install binderhub-test binderhub \
-              --values ./k8s-binder-k8s-hub/binderhub-chart-config.yaml \
+              --values "$old_config" \
               --repo https://jupyterhub.github.io/helm-chart/ \
+              --disable-openapi-validation \
               --version=$UPGRADE_FROM_VERSION
 
       - name: "Helm diff latest released dev chart with local chart"

.github/workflows/test.yml

@@ -167,10 +167,19 @@ jobs:
           #
           #        https://github.com/helm/helm/issues/9244
           cd ci
+
+          old_config="../testing/k8s-binder-k8s-hub/binderhub-chart-config-old.yaml"
+          if [ -f "$old_config" ]; then
+            echo "using old config"
+          else
+            old_config="../testing/k8s-binder-k8s-hub/binderhub-chart-config.yaml"
+          fi
+
           helm install binderhub-test \
               --repo https://jupyterhub.github.io/helm-chart/ binderhub \
+              --disable-openapi-validation \
               --version=$UPGRADE_FROM_VERSION \
-              --values ../testing/k8s-binder-k8s-hub/binderhub-chart-config.yaml \
+              --values "$old_config" \
               --set config.BinderHub.hub_url=http://localhost:30902 \
               --set config.BinderHub.hub_url_local=http://proxy-public \
               --set config.GitHubRepoProvider.access_token=$GITHUB_ACCESS_TOKEN \

testing/k8s-binder-k8s-hub/binderhub-chart-config-old.yaml

@@ -0,0 +1,63 @@
+# (DELETE ME)
+# this file should be removed immediately after merging PR #1472
+
+service:
+  type: NodePort
+  nodePort: 30901
+
+config:
+  BinderHub:
+    # Use the internal host name for Pod to Pod communication
+    # We can't use `hub_url` here because that is set to localhost which
+    # works on the host but not from within a Pod
+    hub_url_local: http://proxy-public
+    use_registry: false
+    log_level: 10
+    cors_allow_origin: "*"
+
+templates:
+  page.html: |
+    {% extends "templates/page.html" %}
+    {% block footer %}
+    {{ super() }}
+    <span>test-template</span>
+    {% endblock %}
+
+ingress:
+  # Enabled to test the creation/update of the k8s Ingress resource, but not
+  # used actively in our CI system.
+  enabled: true
+
+dind:
+  # Not enabled to test the creation/update of the image-cleaner DaemonSet
+  # resource because it also requires us to setup a container registry to test
+  # against which we haven't. We currently only test this via
+  # lint-and-validate-values.yaml that makes sure our rendered templates are
+  # valid against a k8s api-server.
+  enabled: false
+
+# NOTE: This is a mirror of the jupyterhub section in
+#       jupyterhub-chart-config.yaml in testing/local-binder-k8s-hub, keep these
+#       two files synced please.
+jupyterhub:
+  debug:
+    enabled: true
+
+  hub:
+    config:
+      BinderSpawner:
+        cors_allow_origin: "*"
+    db:
+      type: "sqlite-memory"
+
+  proxy:
+    service:
+      type: NodePort
+      nodePorts:
+        http: 30902
+
+  singleuser:
+    storage:
+      type: none
+    memory:
+      guarantee: null

testing/k8s-binder-k8s-hub/binderhub-chart-config.yaml

@@ -1,5 +1,9 @@
 # This config is used when both BinderHub and the JupyterHub it uses are
 # deployed to a kubernetes cluster.
+# note: when changing the config schema,
+# the old version of this file may need to be copied to ./binderhub-chart-config-old.yaml
+# before updating, and then deleted in a subsequent PR.
+
 service:
   type: NodePort
   nodePort: 30901