Enhance build taget into Makefile, add --version support

.gitignore

@@ -1 +1,3 @@
-docker-multi-arch-builder
+
+# Ignore compilation result
+bin/

Makefile

@@ -1,5 +1,20 @@
 .PHONY: build
 
+GOARCH=amd64
+# GOARCH=arm
+GOOS=darwin
+# GOOS=linux
+LDFLAGS=-w -s -X go/weather/internal/version.Version=$$(git rev-list -1 HEAD)
+GO_BUILD_FLAGS=-tags dev
+CGO_ENABLED=0
 
-build:
-	go build
+build: dependencies
+	@echo "build for os $$GOOS and arch $$GOARCH"
+	go build -o bin/docker-multi-arch-builder-$(GOOS)-$(GOARCH) -ldflags="$(LDFLAGS)" $(GO_BUILD_FLAGS) main.go
+
+dependencies:
+	go mod download
+	go mod verify
+
+version:
+	./bin/docker-multi-arch-builder-darwin-amd64 --version

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	. "antoine-roux.tk/docker-multi-arch-builder/internal/version"
 	"fmt"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -15,6 +16,7 @@ var (
 		Short: "dmab is an oci multi architecture builder",
 		Long: `docker multi architecture builder is a go program use to build docker manifest
 with list of layer. Each layer point to docker image with annotated os, arch and variant information`,
+		Version: Version,
 	}
 )
 

internal/version/dev.go

@@ -0,0 +1,21 @@
+//go:build dev
+
+package version
+
+import (
+	"fmt"
+)
+
+//Version ...
+var Version = "0.1.0"
+
+//Prerelease such as "dev" (in development), "beta", "rc1", etc.
+var Prerelease = "dev"
+
+// String returns the complete version string, including prerelease
+func String() string {
+	if Prerelease != "" {
+		return fmt.Sprintf("%s-%s", Version, Prerelease)
+	}
+	return Version
+}

internal/version/prod.go

@@ -0,0 +1,27 @@
+//go:build prod
+
+package version
+
+import (
+	"fmt"
+
+	version "github.com/hashicorp/go-version"
+)
+
+//Version ...
+var Version = "1.0.0"
+
+//Prerelease such as "dev" (in development), "beta", "rc1", etc.
+var Prerelease = "prod"
+
+//SemVer management
+var SemVer *version.Version
+
+func init() {
+	SemVer = version.Must(version.NewSemver(fmt.Sprintf("%s-%s", Version, Prerelease)))
+}
+
+// String returns the complete version string, including prerelease
+func String() string {
+	return SemVer.String()
+}