tmp - adding generation/observedGeneration stuff

Signed-off-by: Yoni Bettan <[email protected]>

docs/enhancements/0002-container-runtime.md

@@ -34,12 +34,15 @@ at ~100% automation for handlering images - everything the cluster does when pul
 
 The new CRD will hold information regarding the existance of images mentioned in `Module` objects.
 The cluster will contain a single `ModuleImagesConfig` per `Module` in the cluster.
+The `generation` and `observedGeneration` are used to trigger the `ModuleImagesConfig` controller in some cases.
 
 ```yaml
 apiVersion: kmm.sigs.x-k8s.io/v1beta1
 kind: ModuleImagesConfig
 metadata:
   ...
+  generation: 1 # default value
+  ...
 spec:
   items:
     - image: registry.example.com/org/kmod1:kver
@@ -50,6 +53,7 @@ spec:
         ...
     - image: registry.example.com/org/kmod3:kver
 status
+  obserevedGeneration: 1
   items:
     - image: registry.example.com/org/kmod1:kver
       status: Exists
@@ -59,7 +63,8 @@ status
 
 ### Module-NMC controller's changes
 
-* The only controller creating `ModuleImagesConfig` objects - one per `Module`
+* The only controller creating or modifying `ModuleImagesConfig` objects - one per `Module`
+* On the first creation the `generation` is set to `1` and increased by one on each `Module` reconciliation.
 * Checking `ModuleImagesConfig`'s status to determine whether the defined image exists in the image
   repository or not.
 * Continues to create `NodeModulesConfig` objects as before.
@@ -84,16 +89,23 @@ flowchart TD
 flowchart TD
     MIC((ModuleImagesConfig)) -->|Reconcile| MICC(MIC controller)
     MICC --> |Image has no status| J1((.))
-        J1 --> |No pull pod| POD((Pull Pod)) --> DONE(((Done)))
         J1 --> |Pull pod exists| J2((.))
-            J2 --> |Succeed| A1{{Update status to 'Exists'}} --> DONE
-            J2 --> |Failed| A2{{Update status to 'DoesNotExist'}} --> DONE
+            J2 --> |Succeed| A1{{Update status to 'Exists' && observedGeneration++}}
+                A1 --> DELETE{{Delete the pod}}
+                    DELETE --> DONE(((Done)))
+            J2 --> |Failed| A2{{Update status to 'DoesNotExist' && observedGeneration++}}
+                A2 --> DELETE
+        J1 --> |No pull pod| POD((Pull Pod)) --> DONE
     MICC --> |status='Exists'| DONE
     MICC --> |status='DoesNotExist'| J3((.))
-        J3 --> |Failed build pod exists or no build section| J4((.))
-            J4 --> |Succeed| A3{{Update status to 'Exists'}} --> DONE
-            J4 --> |Failed| DONE
-        J3 --> |No build pod| BUILD((Build Pod)) --> DONE
+        J3 --> |'generation'!='observedGeneration'| J1
+        J3 --> |'generation'=='observedGeneration'| J6((.))
+            J6 --> |Build section exists| J7((.))
+                J7 --> |No build pod| BUILD((Build Pod)) --> DONE
+                J7 --> |Build pod exist| J8((.))
+                    J8 --> |Succeed| A1{{Update status to 'Exists'}}
+                    J8 --> |Failed| DONE
+            J6 --> |No build section| DONE
 ```
 
 ## Addressing goals