build: add YAML linting

PR-URL: #40007
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

.gitignore

@@ -9,18 +9,19 @@
 !deps/**/.*
 !test/fixtures/**/.*
 !.clang-format
+!.cpplint
 !.editorconfig
 !.eslintignore
 !.eslintrc.js
+!.eslintrc.yaml
 !.flake8
 !.gitattributes
 !.github
 !.gitignore
 !.gitkeep
 !.mailmap
 !.nycrc
-!.eslintrc.yaml
-!.cpplint
+!.yamllint.yaml
 
 # === Rules for root dir ===
 /core

.yamllint.yaml

@@ -0,0 +1,8 @@
+extends: relaxed
+
+rules:
+  line-length: disable
+
+ignore: |
+  /deps/
+  node_modules/

Makefile

@@ -1389,13 +1389,13 @@ cpplint: lint-cpp
 
 .PHONY: lint-py-build
 # python -m pip install flake8
-# Try with '--system' is to overcome systems that blindly set '--user'
+# Try with '--system' if it fails without; the system may have set '--user'
 lint-py-build:
 	$(info Pip installing flake8 linter on $(shell $(PYTHON) --version)...)
 	$(PYTHON) -m pip install --upgrade -t tools/pip/site-packages flake8 || \
 		$(PYTHON) -m pip install --upgrade --system -t tools/pip/site-packages flake8
 
-ifneq ("","$(wildcard tools/pip/site-packages)")
+ifneq ("","$(wildcard tools/pip/site-packages/flake8)")
 .PHONY: lint-py
 # Lints the Python code with flake8.
 # Flag the build if there are Python syntax errors or undefined names
@@ -1407,6 +1407,24 @@ lint-py:
 	$(warning Run 'make lint-py-build')
 endif
 
+.PHONY: lint-yaml-build
+# python -m pip install yamllint
+# Try with '--system' if it fails without; the system may have set '--user'
+lint-yaml-build:
+	$(info Pip installing yamllint on $(shell $(PYTHON) --version)...)
+	$(PYTHON) -m pip install --upgrade -t tools/pip/site-packages yamllint || \
+		$(PYTHON) -m pip install --upgrade --system -t tools/pip/site-packages yamllint
+
+.PHONY: lint-yaml
+# Lints the YAML files with yamllint.
+lint-yaml:
+	@if [ -d "tools/pip/site-packages/yamllint" ]; then \
+			PYTHONPATH=tools/pip $(PYTHON) -m yamllint .; \
+	else \
+		echo 'YAML linting with yamllint is not available'; \
+		echo "Run 'make lint-yaml-build'"; \
+	fi
+
 .PHONY: lint
 .PHONY: lint-ci
 ifneq ("","$(wildcard tools/node_modules/eslint/)")
@@ -1416,11 +1434,12 @@ lint: ## Run JS, C++, MD and doc linters.
 	$(MAKE) lint-cpp || EXIT_STATUS=$$? ; \
 	$(MAKE) lint-addon-docs || EXIT_STATUS=$$? ; \
 	$(MAKE) lint-md || EXIT_STATUS=$$? ; \
+	$(MAKE) lint-yaml || EXIT_STATUS=$$? ; \
 	exit $$EXIT_STATUS
 CONFLICT_RE=^>>>>>>> [[:xdigit:]]+|^<<<<<<< [[:alpha:]]+
 
 # Related CI job: node-test-linter
-lint-ci: lint-js-ci lint-cpp lint-py lint-md lint-addon-docs
+lint-ci: lint-js-ci lint-cpp lint-py lint-md lint-addon-docs lint-yaml-build lint-yaml
 	@if ! ( grep -IEqrs "$(CONFLICT_RE)" --exclude="error-message.js" benchmark deps doc lib src test tools ) \
 		&& ! ( $(FIND) . -maxdepth 1 -type f | xargs grep -IEqs "$(CONFLICT_RE)" ); then \
 		exit 0 ; \