Add header to backports base template

Makefile

@@ -24,17 +24,7 @@ BACKPORTS_BASE_FILE := $(BACKPORTS_BASE_DIR)/Base.gitlab-ci.yml
 #       make it the standard `sed` binary (if you wish) or temporarily alias sed=gsed
 backports:
 	@mkdir -p $(BACKPORTS_BASE_DIR)
-	@echo 'variables:' > $(BACKPORTS_BASE_FILE)
-	@echo '  # OpenTofu CI/CD component version, see https://gitlab.com/components/opentofu/-/releases' >> $(BACKPORTS_BASE_FILE)
-	@echo '  VERSION: "0.1.0-alpha4"' >> $(BACKPORTS_BASE_FILE)
-	@echo '  # Compatible OpenTofu version, see https://gitlab.com/components/opentofu/-/releases' >> $(BACKPORTS_BASE_FILE)
-	@echo '  OPENTOFU_VERSION: "1.6.0"' >> $(BACKPORTS_BASE_FILE)
-	@echo '  # Job Image with `gitlab-tofu`' >> $(BACKPORTS_BASE_FILE)
-	@echo '  GITLAB_OPENTOFU_IMAGE: registry.gitlab.com/components/opentofu/gitlab-opentofu:$$VERSION-opentofu$$OPENTOFU_VERSION' >> $(BACKPORTS_BASE_FILE)
-	@echo '  # The relative path to the root directory of the OpenTofu project' >> $(BACKPORTS_BASE_FILE)
-	@echo '  TF_ROOT: $${CI_PROJECT_DIR}' >> $(BACKPORTS_BASE_FILE)
-	@echo '  # The name of the state file used by the GitLab Managed Terraform state backend' >> $(BACKPORTS_BASE_FILE)
-	@echo '  TF_STATE_NAME: default' >> $(BACKPORTS_BASE_FILE)
+	@cp $(BACKPORTS_DIR)/.Base.gitlab-ci.yml $(BACKPORTS_BASE_FILE)
 	@sed '1,/^---$$/d' templates/full-pipeline.yml >> $(BACKPORTS_BASE_FILE)
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.stage_validate \]\]/validate/'
 	@sed -i $(BACKPORTS_BASE_FILE) -e 's/$$\[\[ inputs.stage_build \]\]/build/'

backports/.Base.gitlab-ci.yml

+# This template is a port of the OpenTofu CI/CD component at
+# https://gitlab.com/components/opentofu
+# It is generated with the `make backports` command from that project.
+#
+# Please make sure to use the component when your project is hosted on GitLab.com
+# or when you are willing to mirror the component project into your self-managed
+# instance and use it from there.
+#
+# Attention: This template will be removed in favor of the OpenTofu CI/CD component as soon as components
+#            are available for self-managed instances.
+#
+# This specific template is located at:
+# https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/OpenTofu/Base.gitlab-ci.yml
+
+variables:
+  # OpenTofu CI/CD component version, see https://gitlab.com/components/opentofu/-/releases
+  VERSION: "0.1.0-alpha4"
+  # 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
+  # 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
+  TF_STATE_NAME: default

backports/OpenTofu/Base.gitlab-ci.yml

+# This template is a port of the OpenTofu CI/CD component at
+# https://gitlab.com/components/opentofu
+# It is generated with the `make backports` command from that project.
+#
+# Please make sure to use the component when your project is hosted on GitLab.com
+# or when you are willing to mirror the component project into your self-managed
+# instance and use it from there.
+#
+# Attention: This template will be removed in favor of the OpenTofu CI/CD component as soon as components
+#            are available for self-managed instances.
+#
+# This specific template is located at:
+# https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/OpenTofu/Base.gitlab-ci.yml
+
 variables:
   # OpenTofu CI/CD component version, see https://gitlab.com/components/opentofu/-/releases
   VERSION: "0.1.0-alpha4"
   # 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.gitlab.com/components/opentofu/gitlab-opentofu:$$VERSION-opentofu$$OPENTOFU_VERSION
   # The relative path to the root directory of the OpenTofu project
-  TF_ROOT: ${CI_PROJECT_DIR}
+  TF_ROOT: $${CI_PROJECT_DIR}
   # The name of the state file used by the GitLab Managed Terraform state backend
   TF_STATE_NAME: default