Makefile: generate default image name based on current user

Makefile

@@ -3,16 +3,23 @@
 # To re-generate a bundle for another specific version without changing the standard setup, you can:
 # - use the VERSION as arg of the bundle target (e.g make bundle VERSION=0.0.2)
 # - use environment variables to overwrite this value (e.g export VERSION=0.0.2)
-IMAGE_OWNER ?= opendatahub
+ifneq ($(USER),)
+IMAGE_OWNER = $(USER)
+else
+IMAGE_OWNER = opendatahub
+endif
 VERSION ?= 2.4.0
 # IMAGE_TAG_BASE defines the opendatahub.io namespace and part of the image name for remote images.
 # This variable is used to construct full image tags for bundle and catalog images.
 #
 # For example, running 'make bundle-build bundle-push catalog-build catalog-push' will build and push both
 # opendatahub.io/opendatahub-operator-bundle:$VERSION and opendatahub.io/opendatahub-operator-catalog:$VERSION.
-IMAGE_TAG_BASE ?= quay.io/$(IMAGE_OWNER)/opendatahub-operator
+IMAGE_TAG_BASE = quay.io/$(IMAGE_OWNER)/opendatahub-operator
+
+# keep the name based on IMG which already used from command line
+IMG_TAG = latest
 # Update IMG to a variable, to keep it consistent across versions for OpenShift CI
-IMG ?= REPLACE_IMAGE
+IMG = $(IMAGE_TAG_BASE):$(IMG_TAG)
 # BUNDLE_IMG defines the image:tag used for the bundle.
 # You can use it as an arg. (E.g make bundle-build BUNDLE_IMG=<some-registry>/<project-name-bundle>:<tag>)
 BUNDLE_IMG ?= $(IMAGE_TAG_BASE)-bundle:v$(VERSION)