Makefile help target

make help

operator-sdk로 생성된 프로젝트를 보다가 Makefile에 help target이 있었는데, 간편하게 도움말을 작성할 수 있어서 복사해왔습니다.

사용법은 ##@ <category> 아래에 해당 카테고리에 맞는 타겟을 <target>: [dependency] ## <description> 형식으로 나열하면 됩니다. 설명이 없는 타겟은 무시됩니다.

##@ General

# The help target prints out all targets with their descriptions organized
# beneath their categories. The categories are represented by '##@' and the
# target descriptions by '##'. The awk commands is responsible for reading the
# entire set of makefiles included in this invocation, looking for lines of the
# file as xyz: ## something, and then pretty-format the target and help. Then,
# if there's a line with ##@ something, that gets pretty-printed as a category.
# More info on the usage of ANSI control characters for terminal formatting:
# https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters
# More info on the awk command:
# http://linuxcommand.org/lc3_adv_awk.php

.PHONY: help
help: ## Display this help.
	@awk '\
		BEGIN { \
			FS = ":.*##"; \
			printf "\nUsage:\n  make \033[36m<target>\033[0m\n" \
		} \
		/^[a-zA-Z_0-9-]+:.*?##/ { \
			printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 \
		} \
		/^##@/ { \
			printf "\n\033[1m%s\033[0m\n", substr($$0, 5) \
		} \
	' $(MAKEFILE_LIST)

##@ Development

.PHONY: remove-local-branch
remove-local-branch: ## Update remote branches and remove local branches.
	git remote update --prune
	git switch --detach origin/HEAD
	@git for-each-ref --format '%(refname:short)' refs/heads | xargs -r -t git branch -D

$ make help

Usage:
  make <target>

General
  help             Display this help.

Development
  remove-local-branch  Update remote branches and remove local branches.