chore: setup build-info package and env variables in Makefile

Makefile

@@ -1,5 +1,30 @@
 #!/usr/bin/env make
 
+# setup variables
+NAME := auth0-cli
+PKG := github.com/auth0/$(NAME)
+BUILDINFOPKG := $(PKG)/internal/build-info
+
+## setup variables for build-info
+BUILDUSER := $(shell whoami)
+BUILDTIME := $(shell date -u '+%Y-%m-%d %H:%M:%S')
+VERSION := $(GITCOMMIT)
+#BUILDVERSION := $(shell git describe --exact-match --abbrev=0)
+GITCOMMIT := $(shell git rev-parse --short HEAD)
+
+GITUNTRACKEDCHANGES := $(shell git status --porcelain --untracked-files=no)
+ifneq ($(GITUNTRACKEDCHANGES),)
+	GITCOMMIT := $(GITCOMMIT)-dirty
+endif
+
+GITBRANCH ?= $(shell git rev-parse --verify --abbrev-ref HEAD)
+CTIMEVAR = -X '$(BUILDINFOPKG).Version=$(VERSION)' \
+					 -X '$(BUILDINFOPKG).Revision=$(GITCOMMIT)' \
+					 -X '$(BUILDINFOPKG).Branch=$(GITBRANCH)' \
+					 -X '$(BUILDINFOPKG).BuildUser=$(BUILDUSER)' \
+					 -X '$(BUILDINFOPKG).BuildDate=$(BUILDTIME)'
+
+
 generate:
 	go generate ./...
 .PHONY: generate

internal/build-info/build.go

@@ -0,0 +1,40 @@
+package buildinfo
+
+import (
+	"runtime"
+)
+
+var (
+	Version   string
+	Revision  string
+	Branch    string
+	BuildUser string
+	BuildDate string
+	GoVersion = runtime.Version()
+)
+
+type BuildInfo struct {
+	Version   string
+	Revision  string
+	Branch    string
+	BuildUser string
+	BuildDate string
+	GoVersion string
+}
+
+// NewDefaultBuildInfo returns the build information obtained from ldflags
+func NewDefaultBuildInfo() BuildInfo {
+	return NewBuildInfo(Version, Branch, BuildDate, BuildUser, GoVersion, Revision)
+}
+
+// NewBuildInfo returns an object with the build information
+func NewBuildInfo(version, branch, buildDate, buildUser, goVersion, revision string) BuildInfo {
+	return BuildInfo{
+		Version:   version,
+		Branch:    branch,
+		BuildDate: buildDate,
+		BuildUser: buildUser,
+		GoVersion: goVersion,
+		Revision:  revision,
+	}
+}