docker_image_availability: fix local image search

An image in the docker index may be tagged by name or by registry plus
name. In order to find the image correctly locally and prevent looking
for it externally, make sure all possible variations are searched.

roles/openshift_health_checker/openshift_checks/docker_image_availability.py

@@ -139,10 +139,14 @@ class DockerImageAvailability(DockerHostMixin, OpenShiftCheck):
 
     def local_images(self, images):
         """Filter a list of images and return those available locally."""
-        return [
-            image for image in images
-            if self.is_image_local(image)
-        ]
+        registries = self.known_docker_registries()
+        found_images = []
+        for image in images:
+            # docker could have the image name as-is or prefixed with any registry
+            imglist = [image] + [reg + "/" + image for reg in registries]
+            if self.is_image_local(imglist):
+                found_images.append(image)
+        return found_images
 
     def is_image_local(self, image):
         """Check if image is already in local docker index."""
@@ -151,7 +155,7 @@ class DockerImageAvailability(DockerHostMixin, OpenShiftCheck):
 
     def known_docker_registries(self):
         """Build a list of docker registries available according to inventory vars."""
-        regs = list(self.get_var("openshift.docker.additional_registries"))
+        regs = list(self.get_var("openshift.docker.additional_registries", default=[]))
 
         deployment_type = self.get_var("openshift_deployment_type")
         if deployment_type == "origin" and "docker.io" not in regs: