# Simple Makefile to build base VM images using packer and ansible
# TODO
#   * support ssh as user instead of root
#   * testing target
PACKER     ?= packer
ANSIBLE_DIR = ansible-roles


# check which hypervisors are available
ifndef BUILDER
    ifeq ($(shell which qemu-system-$(shell uname -m | sed 's/i686/i386/') 2>&1 > /dev/null && echo $$?), 0)
        AVAILABLE_BUILDERS += qemu
    endif

    ifeq ($(shell which virtualbox 2>&1 > /dev/null && echo $$?), 0)
        AVAILABLE_BUILDERS += virtualbox-iso
    endif

    ifeq ($(shell which vmplayer 2>&1 > /dev/null && echo $$?), 0)
        AVAILABLE_BUILDERS += vmware-iso
    endif

    BUILDER := $(firstword $(AVAILABLE_BUILDERS))
endif


# The packer templates, detected as *.json (excluding base.json)
TEMPLATES := $(basename $(filter-out base.json,$(wildcard *.json)))

# The provisioning flavors, detected as ansible-roles/setup-<flavor>.yml
FLAVORS := $(patsubst $(ANSIBLE_DIR)/setup-%.yml,%, $(wildcard $(ANSIBLE_DIR)/setup-*.yml))

BASETARGETS := $(foreach template, $(TEMPLATES), $(template)/base)
PROVTARGETS := $(foreach template, $(TEMPLATES), $(foreach flavor, $(FLAVORS), $(template)/$(flavor)))
BOOTTARGETS := $(foreach template, $(TEMPLATES), $(template)/base/boot)
BOOTTARGETS += $(foreach prov, $(PROVTARGETS), $(prov)/boot)


PACKER_OPTS := -var-file=base.json
ifdef DEBUG
    VERBOSE     := 1
    PACKER_OPTS += -debug
endif


# We support parallel Provisioning packer builds.
# To ensure data consistency we save the used ansible roles before executing in
# its own environment, tagged by the current date & time.
TIMESTAMP := $(shell date "+%Y-%m-%d_%H-%M-%S")


ifdef VERBOSE
    PACKER_OPTS += -var='headless=false'

    $(info root password:        $(ROOTPW))
    $(info )
    $(info timestamp:            $(TIMESTAMP))
    $(info )
    $(info packer: executable:   $(PACKER))
    $(info packer: options:      $(PACKER_OPTS))
    $(info )
    $(info ansible: directory:   $(ANSIBLE_DIR))
    $(info )
    $(info builder: available:   $(AVAILABLE_BUILDERS))
    $(info builder: chosen:      $(BUILDER))
    $(info )
    $(info targets: base:        $(strip $(BASETARGETS)))
    $(info targets: boot:        $(strip $(BOOTTARGETS)))
    $(info targets: provision:   $(strip $(PROVTARGETS)))
    $(info )
endif

HASHER := sha256sum
check_rootpw = $(if $(strip $(ROOTPW)),\
    $(if $1,\
        $(if $(shell echo $(ROOTPW) | $(HASHER) --check --quiet $1/base/rootpw.$(HASHER)),\
             $(error ROOTPW password hash does not match $1/base/rootpw.$(HASHER)),\
             ),\
        ),\
    $(error No root password is set, set it as ROOTPW in your environment.) \
)


.PHONY: help clean
help:


# Creating base images
$(BASETARGETS):
	$(call check_rootpw)
	$(info ** Building template '$(@D)' using '$(BUILDER)' **)
	$(PACKER) build -only=$(BUILDER) \
		$(PACKER_OPTS) \
		-var='vm_name=rootfs-image' \
		-var='output_directory=$(@D)/base' \
		$(@D).json
	@echo $(ROOTPW) | $(HASHER) > $(@D)/base/rootpw.$(HASHER)


# Provisioning images
$(PROVTARGETS):
$(foreach flav, $(FLAVORS), %/$(flav)): %/base
	$(call check_rootpw,$(@D))
	$(eval BUILD_DIR := $(@D)/$(@F).$(TIMESTAMP))
	$(info ** Provisioning '$(@D)' with '$(@F)' **)
	@mkdir -p $(BUILD_DIR)
	@cp -r $(ANSIBLE_DIR) $(BUILD_DIR)/$(ANSIBLE_DIR)
	$(PACKER) build -only=$(BUILDER) \
		$(PACKER_OPTS) \
		-var='vm_name=rootfs-image' \
		-var='output_directory=$(BUILD_DIR)/build' \
		-var='base_image=$(@D)/base/rootfs-image' \
		-var='playbook=setup-$(@F).yml' \
		$(BUILD_DIR)/$(ANSIBLE_DIR)/run-playbook-only.json
	@ln -sfn $(@F).$(TIMESTAMP) $(@D)/$(@F).latest


# Generating boot files
$(BOOTTARGETS):
%/boot: %
	$(call check_rootpw,$(@D))
	$(eval BUILD_DIR := $(@D).$(TIMESTAMP))
	$(info ** Generating boot files for '$(BUILD_DIR)')
	$(PACKER) build -only=$(BUILDER) \
		$(PACKER_OPTS) \
		-var='vm_name=rootfs-image.tmp' \
		-var='output_directory=$(BUILD_DIR)/build/tmp' \
		-var='base_image=$(BUILD_DIR)/build/rootfs-image' \
		-var='playbook=build-dracut-initramfs.yml' \
		$(BUILD_DIR)/$(ANSIBLE_DIR)/run-playbook-only.json
	@mv $(BUILD_DIR)/$(ANSIBLE_DIR)/boot_files $(BUILD_DIR)/build/boot


# The builds directories are named after the template name
# TODO: needs refactoring
clean:
	-$(foreach build_dir,$(TEMPLATES),test -d $(build_dir) && rm -rf $(build_dir);)


help:
	@printf "Usage:\n\tmake <template>/<flavor>[/boot]\n"
	@echo
	@echo "Base images targets:"
	@for T in $(BASETARGETS); do printf "\t%s\n" "$$T"; done
	@echo
	@echo "Provisioning images targets: "
	@for P in $(PROVTARGETS); do printf "\t%s\n" "$$P"; done
	@echo
	@echo "Generate boot files targets:"
	@printf "\t<{base,provisioning}_target>/boot\n"