Makefile: implement helper to process OpenShift templates

just for manual checks if the template syntax is fine
and align with the github action to use the same code

.github/workflows/tests.yml

@@ -276,15 +276,7 @@ jobs:
     - uses: redhat-actions/oc-installer@v1
     - name: Process template
       run: |
-        mkdir processed-templates
-        oc process -f templates/openshift/composer.yml \
-          -p IMAGE_TAG=image_tag \
-          --local \
-          -o yaml > processed-templates/composer.yml
-        oc process -f templates/openshift/maintenance.yml \
-          -p IMAGE_TAG=image_tag \
-          --local \
-          -o yaml > processed-templates/maintenance.yml
+        make process-templates
 
     - uses: stackrox/kube-linter-action@v1.0.5
       with:

.gitignore

@@ -15,3 +15,5 @@ __pycache__
 /docs/osbuild-composer.7
 .cache
 container_composer_golangci_built.info
+processed-templates
+

Makefile

@@ -89,6 +89,7 @@ help:
 	@echo "    push-check:         Replicates the github workflow checks as close as possible"
 	@echo "                        (do this before pushing!)"
 	@echo "    lint:               Runs linters as close as github workflow as possible"
+	@echo "    process-templates:  Execute the OpenShift CLI to check the templates"
 
 $(BUILDDIR)/:
 	mkdir -p "$@"
@@ -166,6 +167,7 @@ clean:
 	rm -rf $(BUILDDIR)/bin/
 	rm -rf $(CURDIR)/rpmbuild
 	rm -rf container_composer_golangci_built.info
+	rm -rf $(BUILDDIR)/$(PROCESSED_TEMPLATE_DIR)
 
 .PHONY: push-check
 push-check: lint build unit-tests srpm man
@@ -293,3 +295,24 @@ container_composer_golangci_built.info: Makefile Containerfile_golangci_lint too
 .PHONY: lint
 lint: $(GOLANGCI_LINT_CACHE_DIR) container_composer_golangci_built.info
 	podman run -t --rm -v $(SRCDIR):/app:z -v $(GOLANGCI_LINT_CACHE_DIR):/root/.cache:z -w /app $(GOLANGCI_COMPOSER_IMAGE) golangci-lint run -v
+
+# The OpenShift CLI - maybe get it from https://access.redhat.com/downloads/content/290
+OC_EXECUTABLE ?= oc
+
+OPENSHIFT_TEMPLATES_DIR := templates/openshift
+OPENSHIFT_TEMPLATES := $(notdir $(wildcard $(OPENSHIFT_TEMPLATES_DIR)/*.yml))
+
+PROCESSED_TEMPLATE_DIR := $(BUILDDIR)/processed-templates
+
+$(PROCESSED_TEMPLATE_DIR): $(BUILDDIR)
+	mkdir -p $@
+
+$(PROCESSED_TEMPLATE_DIR)/%.yml: $(PROCESSED_TEMPLATE_DIR) $(OPENSHIFT_TEMPLATES_DIR)/%.yml
+	$(OC_EXECUTABLE) process -f $(OPENSHIFT_TEMPLATES_DIR)/$*.yml \
+          -p IMAGE_TAG=image_tag \
+          --local \
+          -o yaml > $@
+
+.PHONY: process-templates
+process-templates: $(addprefix $(PROCESSED_TEMPLATE_DIR)/, $(OPENSHIFT_TEMPLATES))
+