fix: Make the metacontroller image configurable (#83)

Expose the metacontroller image in config.yaml, so that it can be set
either pre or post deployment. This also ensures that the image is
always pulled from the specified source and not a private registry,
which the metacontroller StatefulSet doesn't have permission to access.

Signed-off-by: Phoevos Kalemkeris <phoevos.kalemkeris@canonical.com>

config.yaml

@@ -0,0 +1,5 @@
+options:
+  metacontroller-image:
+    type: string
+    default: docker.io/metacontrollerio/metacontroller:v3.0.0
+    description: Metacontroller image

metadata.yaml

@@ -7,11 +7,6 @@ description: |
 assumes:
   - juju >= 2.9
 summary: An add-on for Kubernetes to write and deploy custom controllers from simple scripts
-resources:
-  oci-image:
-    type: oci-image
-    description: OCI image for metacontroller
-    upstream-source: docker.io/metacontrollerio/metacontroller:v3.0.0
 provides:
   metrics-endpoint:
     interface: prometheus_scrape

src/charm.py

@@ -13,7 +13,6 @@
 from lightkube import codecs
 from lightkube.core.exceptions import ApiError
 from lightkube.resources.apps_v1 import StatefulSet
-from oci_image import OCIImageResource, OCIImageResourceError
 from ops.charm import CharmBase
 from ops.main import main
 from ops.model import ActiveStatus, BlockedStatus, MaintenanceStatus, WaitingStatus
@@ -47,14 +46,14 @@ def __init__(self, *args):
         self.dashboard_provider = GrafanaDashboardProvider(self)
 
         self.framework.observe(self.on.install, self._install)
+        self.framework.observe(self.on.config_changed, self._install)
         self.framework.observe(self.on.update_status, self._update_status)
 
         self.logger: logging.Logger = logging.getLogger(__name__)
 
         self._name: str = self.model.app.name
         self._namespace: str = self.model.name
-        self._metacontroller_image_resource = OCIImageResource(self, "oci-image")
-        self._metacontroller_image = self._fetch_image_path()
+        self._metacontroller_image = self.model.config["metacontroller-image"]
         self._resource_files: dict = {
             "crds": "metacontroller-crds-v1.yaml",
             "rbac": "metacontroller-rbac.yaml",
@@ -203,13 +202,6 @@ def _get_manifest_files(self) -> list:
         """Returns a list of all manifest files"""
         return glob.glob(str(self._manifest_file_root / "*.yaml"))
 
-    def _fetch_image_path(self):
-        try:
-            image_details = self._metacontroller_image_resource.fetch()
-        except OCIImageResourceError as e:
-            raise CheckFailed(f"{e.status.message}", e.status_type)
-        return image_details.get("imagePath")
-
     @property
     def lightkube_client(self):
         if not self._lightkube_client:

tests/unit/test_charm.py

@@ -29,14 +29,6 @@ def harness():
 def harness_with_charm(harness):
     harness.set_leader(True)
     harness.set_model_name("test-namespace")
-    harness.add_oci_resource(
-        "oci-image",
-        {
-            "registrypath": "image",
-            "username": "",
-            "password": "",
-        },
-    )
     harness.begin()
     return harness
 

tools/get-images.sh

@@ -4,6 +4,6 @@
 #
 # dynamic list
 IMAGE_LIST=()
-IMAGE_LIST+=($(find -type f -name metadata.yaml -exec yq '.resources | to_entries | .[] | .value | ."upstream-source"' {} \;))
+IMAGE_LIST+=($(find -type f -name config.yaml -exec yq eval .options.metacontroller-image.default {} \;))
 printf "%s\n" "${IMAGE_LIST[@]}"