feat: add a dynamic, relation-driven sidebar (#118)

Changes include:
* adding KubeflowDashboardSidebarRequirer
* adding KubeflowDashboardSidebarProvider
* adding SidebarItem
* adding associated tests, including a Requires side tester for the new relation
* adding the sidebar relation and using the KubeflowDashboardSidebarProvider to manage it
* refactoring computation of k8s context until it is needed, instead of in `__init__`, to make testing easier

.github/workflows/integrate.yaml

@@ -77,29 +77,14 @@ jobs:
         run: |
           sg microk8s -c "tox -e integration -- --model kubeflow"
 
-      - name: Get all
-        run: kubectl get all -A
-        if: failure()
-
-      - name: Get configmaps
-        run: kubectl get cm -A
-        if: failure()
-
       - name: Get juju status
         run: juju status
         if: failure()
 
-      - name: Get kubeflow-profiles workload logs
-        run: kubectl logs --tail 100 -nkubeflow -ljuju-app=kubeflow-dashboard
-        if: failure()
-
-      - name: Get kubeflow-kfam workload logs
-        run: kubectl logs --tail 100 -nkubeflow -ljuju-app=kubeflow-dashboard
-        if: failure()
-
-      - name: Get operator logs
-        run: kubectl logs --tail 100 -nkubeflow -loperator.juju.is/name
-        if: failure()
+      - uses: canonical/kubeflow-ci/actions/dump-charm-debug-artifacts@main
+        # always() if you want this to run on every run, regardless of failure.
+        # more details: https://docs.github.com/en/actions/learn-github-actions/expressions#status-check-functions
+        if: always()
 
       - name: Upload selenium screenshots
         uses: actions/upload-artifact@v3

lib/charms/harness_extensions/v0/capture_events.py

@@ -0,0 +1,86 @@
+'''This is a library providing a utility for unittesting events fired on a
+Harness-ed Charm.
+
+Example usage:
+
+>>> from charms.harness_extensions.v0.capture_events import capture
+>>> with capture(RelationEvent) as captured:
+>>>     harness.add_relation('foo', 'remote')
+>>> assert captured.event.unit.name == 'remote'
+'''
+
+# The unique Charmhub library identifier, never change it
+LIBID = "9fcdab70e26d4eee9797c0e542ab397a"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 3
+
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+from contextlib import contextmanager
+from typing import Generic, Iterator, Optional, Type, TypeVar
+
+from ops.charm import CharmBase
+from ops.framework import EventBase
+
+_T = TypeVar("_T", bound=EventBase)
+
+
+@contextmanager
+def capture_events(charm: CharmBase, *types: Type[EventBase]):
+    """Capture all events of type `*types` (using instance checks)."""
+    allowed_types = types or (EventBase,)
+
+    captured = []
+    _real_emit = charm.framework._emit
+
+    def _wrapped_emit(evt):
+        if isinstance(evt, allowed_types):
+            captured.append(evt)
+        return _real_emit(evt)
+
+    charm.framework._emit = _wrapped_emit  # type: ignore # noqa # ugly
+
+    yield captured
+
+    charm.framework._emit = _real_emit  # type: ignore # noqa # ugly
+
+
+class Captured(Generic[_T]):
+    """Object to type and expose return value of capture()."""
+
+    _event = None
+
+    @property
+    def event(self) -> Optional[_T]:
+        """Return the captured event."""
+        return self._event
+
+    @event.setter
+    def event(self, val: _T):
+        self._event = val
+
+
+@contextmanager
+def capture(charm: CharmBase, typ_: Type[_T] = EventBase) -> Iterator[Captured[_T]]:
+    """Capture exactly 1 event of type `typ_`.
+
+    Will raise if more/less events have been fired, or if the returned event
+    does not pass an instance check.
+    """
+    result = Captured()
+    with capture_events(charm, typ_) as captured:
+        if not captured:
+            yield result
+
+    assert len(captured) <= 1, f"too many events captured: {captured}"
+    assert len(captured) >= 1, f"no event of type {typ_} emitted."
+    event = captured[0]
+    assert isinstance(event, typ_), f"expected {typ_}, not {type(event)}"
+    result.event = event
+