Rename image registry base variable

Makefile

+all: docs backports
+
+.PHONY: docs
 docs:
 	csplit -sf readme -n 1 .gitlab/README.md '/<INPUTS>/'
 	echo '<!-- This document is generated by `make docs` from `.gitlab/README.md` -->' > README.md
@@ -23,6 +26,7 @@ BACKPORTS_BASE_FILE := $(BACKPORTS_BASE_DIR)/Base.gitlab-ci.yml
 #       Install it with `brew install gnu-sed` and follow the instructions in `brew info gnu-sed` to 
 #       make it the standard `sed` binary (if you wish) or temporarily alias sed=gsed
 backports:
+	@echo "Generating $(BACKPORTS_BASE_FILE) ..."
 	@mkdir -p $(BACKPORTS_BASE_DIR)
 	@cp $(BACKPORTS_DIR)/.Base.gitlab-ci.yml $(BACKPORTS_BASE_FILE)
 	@sed '1,/^---$$/d' templates/full-pipeline.yml >> $(BACKPORTS_BASE_FILE)
@@ -30,7 +34,7 @@ backports:
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.stage_build \]\]/build/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.stage_deploy \]\]/deploy/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.stage_cleanup \]\]/cleanup/'
-	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs._image_registry_base \]\]/$$GITLAB_OPENTOFU_IMAGE_REGISTRY_BASE/'
+	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.image_registry_base \]\]/$$GITLAB_OPENTOFU_IMAGE_REGISTRY_BASE/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.version \]\]/$$GITLAB_OPENTOFU_VERSION/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.opentofu_version \]\]/$$OPENTOFU_VERSION/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.root_dir \]\]/$$TF_ROOT/'
@@ -47,3 +51,4 @@ backports:
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/destroy:/.opentofu:destroy:/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e '/needs: \[destroy\]/d'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/^delete-state:$$/.opentofu:delete-state:/'
+	@echo "Generated $(BACKPORTS_BASE_FILE)"

backports/.Base.gitlab-ci.yml

@@ -18,7 +18,7 @@ variables:
   # Compatible OpenTofu version, see https://gitlab.com/components/opentofu/-/releases
   OPENTOFU_VERSION: "1.6.0"
   # Job Image with `gitlab-tofu`
-  GITLAB_OPENTOFU_IMAGE: registry.gitlab.com/components/opentofu/gitlab-opentofu:$VERSION-opentofu$OPENTOFU_VERSION
+  GITLAB_OPENTOFU_IMAGE_REGISTRY_BASE: $CI_REGISTRY/components/opentofu
   # The relative path to the root directory of the OpenTofu project
   TF_ROOT: ${CI_PROJECT_DIR}
   # The name of the state file used by the GitLab Managed Terraform state backend

backports/OpenTofu/Base.gitlab-ci.yml

@@ -18,7 +18,7 @@ variables:
   # Compatible OpenTofu version, see https://gitlab.com/components/opentofu/-/releases
   OPENTOFU_VERSION: "1.6.0"
   # Job Image with `gitlab-tofu`
-  GITLAB_OPENTOFU_IMAGE: registry.gitlab.com/components/opentofu/gitlab-opentofu:$VERSION-opentofu$OPENTOFU_VERSION
+  GITLAB_OPENTOFU_IMAGE_REGISTRY_BASE: $CI_REGISTRY/components/opentofu
   # The relative path to the root directory of the OpenTofu project
   TF_ROOT: ${CI_PROJECT_DIR}
   # The name of the state file used by the GitLab Managed Terraform state backend

templates/full-pipeline.yml

@@ -30,7 +30,7 @@ spec:
       description: 'OpenTofu version that should be used.'
 
     # Images
-    _image_registry_base:
+    image_registry_base:
       default: '$CI_REGISTRY/components/opentofu'
     # FIXME: not yet possible because of https://gitlab.com/gitlab-org/gitlab/-/issues/438722
     # gitlab_opentofu_image:
@@ -64,7 +64,7 @@ spec:
 
 .default:
   image:
-    name: '$[[ inputs._image_registry_base ]]/gitlab-opentofu:$[[ inputs.version ]]-opentofu$[[ inputs.opentofu_version ]]'
+    name: '$[[ inputs.image_registry_base ]]/gitlab-opentofu:$[[ inputs.version ]]-opentofu$[[ inputs.opentofu_version ]]'
 
   variables:
     TF_ROOT: $[[ inputs.root_dir ]]

tests/integration-tests/Defaults.gitlab-ci.yml

 include:
   - component: gitlab.com/$CI_PROJECT_PATH/full-pipeline@$CI_COMMIT_SHA
     inputs:
-      _image_registry_base: $GITLAB_OPENTOFU_IMAGE_BASE
+      image_registry_base: $GITLAB_OPENTOFU_IMAGE_BASE
       version: $CI_COMMIT_SHA
       opentofu_version: $OPENTOFU_VERSION
       root_dir: $TEST_TF_ROOT