DOTENV in Makefile

Makefile

# If there is a .env file, create a temporary copy of it, in a format supported by Makefile
# where every variable become a fallback. "FOO=bar" becomes "FOO?=bar"
ifneq (,$(wildcard ./.env))
	DOTENV_PATH=/tmp/$(shell echo $$(pwd) | base64)
	include $(shell cat .env | grep -v --perl-regexp '^('$$(env | sed 's/=.*//'g | tr '\n' '|')')\=' | sed 's/=/?=/g' > $(DOTENV_PATH); echo '$(DOTENV_PATH)')
endif

# Expose all defined variables to subprocesses.
export

# Then, other targets
.PHONY: up
up:
	docker-compose up -d