Makefile

SIGNATURE__API = $(shell find api -type f -name "*.yaml" | sort | bin/sign | bin/update-if-different $(SIGNATURE_DIRECTORY)/api)

$(MAKE_DIRECTORY)/api: $(SIGNATURE__API) bin/dsl-api
	bin/dsl-api -strict -root api/gen.a.root.yaml
	@touch $@

api: $(MAKE_DIRECTORY)/api


################################################################################
# bin/gb
################################################################################
bin/gb-$(HOST_GO_OS_ARCH_SUFFIX): bin/go $(SIGNATURE__GO__VENDOR)
	(cd vendor && GOOS=$(HOST_GOOS) GOARCH=$(HOST_GOARCH) ../bin/go install github.com/constabulary/gb/cmd/gb)
	cp vendor/bin/gb bin/gb-$(HOST_GO_OS_ARCH_SUFFIX)

bin/gb: bin/gb-$(HOST_GO_OS_ARCH_SUFFIX) make/03.generate.os.arch.switcher.sh
	make/03.generate.os.arch.switcher.sh gb

clean-bin-gb:
	$(info [$@])
	rm -f bin/gb*

################################################################################
# bin/sign
################################################################################
bin/sign-$(HOST_GO_OS_ARCH_SUFFIX): bin/gb src/cmd/make/sign/main.go
	GOOS=$(HOST_GOOS) GOARCH=$(HOST_GOARCH) bin/gb build cmd/make/sign
	@touch $@

bin/sign: bin/sign-$(HOST_GO_OS_ARCH_SUFFIX) make/03.generate.os.arch.switcher.sh
	GOOS=$(HOST_GOOS) GOARCH=$(HOST_GOARCH) make/03.generate.os.arch.switcher.sh $(@F)

tool: bin/sign

clean-bin-sign:
	$(info [$@])
	rm -f bin/sign*

################################################################################
# bin/update-if-different
################################################################################
bin/update-if-different-$(HOST_GO_OS_ARCH_SUFFIX): bin/gb src/cmd/make/update-if-different/main.go
	GOOS=$(HOST_GOOS) GOARCH=$(HOST_GOARCH) bin/gb build cmd/make/update-if-different
	@touch $@

bin/update-if-different: bin/update-if-different-$(HOST_GO_OS_ARCH_SUFFIX) make/03.generate.os.arch.switcher.sh
	GOOS=$(HOST_GOOS) GOARCH=$(HOST_GOARCH) make/03.generate.os.arch.switcher.sh $(@F)

tool: bin/update-if-different

clean-bin-update-if-different:
	$(info [$@])
	rm -f bin/update-if-different*

sign.go

package main

import (
	"bufio"
	"crypto/md5"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
)

func Usage() {
	fmt.Fprintf(os.Stderr, `Usage: %s
	tool generates <signature-file> of source of files
		1. read file path list from stdin
		2. read content of every file and accumulate MD5
		3. print result MD5 to stdout
	`, os.Args[0])
}

func main() {
	flag.Usage = Usage
	flag.Parse()
	if flag.NArg() != 0 {
		flag.Usage()
		os.Exit(1)
	}

	sum := md5.New()
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		path := scanner.Text()
		if content, err := ioutil.ReadFile(path); err != nil {
			fmt.Fprintf(os.Stderr, "read input '%s' problem %s\n", path, err)
			// TODO: translate error to suitable exit code
			os.Exit(1)
		} else {
			sum.Write([]byte(path))
			sum.Write(content)
		}
	}
	fmt.Fprintf(os.Stdout, "%x\n", sum.Sum(nil))

}

update-if-changed.go

package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
)

func Usage() {
	fmt.Fprintf(os.Stderr, `Usage: %s <marker-file>
	tool update <marker-file> from stdin if different
	`, os.Args[0])
}

func main() {
	var (
		content  []byte
		previous string
		err      error
		actual   string
	)

	flag.Usage = Usage
	flag.Parse()
	if flag.NArg() != 1 {
		flag.Usage()
		os.Exit(1)
	}

	target := flag.Arg(0)

	if content, err = ioutil.ReadFile(target); err == nil {
		previous = string(content)
	}

	if content, err = ioutil.ReadAll(os.Stdin); err == nil {
		actual = string(content)
	} else {
		fmt.Fprintf(os.Stderr, "read STDIN problem %s\n", err)
		// TODO: translate error to suitable exit code
		os.Exit(1)
	}

	parent := filepath.Dir(target)
	if err := os.MkdirAll(parent, 0750); err != nil {
		fmt.Fprintf(os.Stderr, "create parent directory '%s' problem %s\n", parent, err)
		// TODO: translate error to suitable exit code
		os.Exit(1)
	}

	if actual != previous {
		if err := ioutil.WriteFile(target, []byte(actual), 0664); err != nil {
			fmt.Fprintf(os.Stderr, "write <signature-file> '%s' problem %s\n", target, err)
			// TODO: translate error to suitable exit code
			os.Exit(1)
		}
	}

	fmt.Fprintf(os.Stdout, "%s", target)
}