From 7845515f36ef3101236d8390a8393ed322f0345e Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@harshavardhana.net>
Date: Mon, 2 Nov 2015 02:11:34 -0800
Subject: [PATCH] build: Versioning now populated through ldflags

---
 .gitignore                                    |  1 -
 Makefile                                      | 12 ++--
 appveyor.yml                                  |  3 +
 build-constants.go                            | 26 ++++++---
 .../{gen-constants.go => gen-ldflags.go}      | 55 +++----------------
 update-main.go                                |  4 +-
 6 files changed, 36 insertions(+), 65 deletions(-)
 rename buildscripts/{gen-constants.go => gen-ldflags.go} (51%)

diff --git a/.gitignore b/.gitignore
index 6b70180ca..64dc5bcae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
-/build-constants.go
 **/*.swp
 cover.out
 *~
diff --git a/Makefile b/Makefile
index 12288e56d..eb15ab3e4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+LDFLAGS = $(shell go run buildscripts/gen-ldflags.go)
+
 all: install
 
 checkdeps:
@@ -7,6 +9,7 @@ checkdeps:
 checkgopath:
 	@echo "Checking if project is at ${GOPATH}"
 	@for miniopath in $(echo ${GOPATH} | sed 's/:/\n/g'); do if [ ! -d ${miniopath}/src/github.com/minio/minio ]; then echo "Project not found in ${miniopath}, please follow instructions provided at https://github.com/minio/minio/blob/master/CONTRIBUTING.md#setup-your-minio-github-repository" && exit 1; fi done
+	@echo "Setting LDFLAGS: ${LDFLAGS}"
 
 getdeps: checkdeps checkgopath
 	@go get -u github.com/golang/lint/golint && echo "Installed golint:"
@@ -38,7 +41,7 @@ cyclo:
 	@GO15VENDOREXPERIMENT=1 gocyclo -over 65 *.go
 	@GO15VENDOREXPERIMENT=1 gocyclo -over 65 pkg
 
-build: constants getdeps verifiers
+build: getdeps verifiers
 	@echo "Installing minio:"
 
 deadcode:
@@ -50,11 +53,7 @@ test: build
 	@GO15VENDOREXPERIMENT=1 go test $(GOFLAGS) github.com/minio/minio/pkg...
 
 gomake-all: build
-	@GO15VENDOREXPERIMENT=1 go install github.com/minio/minio
-
-constants:
-	@echo "Generating new build-constants.go"
-	@GO15VENDOREXPERIMENT=1 go run buildscripts/gen-constants.go
+	@GO15VENDOREXPERIMENT=1 go build -ldflags $(LDFLAGS) -o $(GOPATH)/bin/minio
 
 pkg-add:
 	@GO15VENDOREXPERIMENT=1 govendor add $(PKG)
@@ -69,7 +68,6 @@ install: gomake-all
 
 clean:
 	@echo "Cleaning up all the generated files:"
-	@rm -fv build-constants.go
 	@rm -fv cover.out
 	@rm -fv minio
 	@rm -fv minio.test
diff --git a/appveyor.yml b/appveyor.yml
index acaa2a189..21c46e5d4 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -26,6 +26,9 @@ build_script:
   - go test -race .
   - go test github.com/minio/minio/pkg...
   - go test -race github.com/minio/minio/pkg...
+  - go run buildscripts/gen-ldflags.go > temp.txt
+  - set /p LDFLAGS=<temp.txt
+  - go build -ldflags=%LDFLAGS% -o %GOPATH%\bin\minio.exe
 
 # to disable automatic tests
 test: off
diff --git a/build-constants.go b/build-constants.go
index ce3e77092..03167e9fb 100644
--- a/build-constants.go
+++ b/build-constants.go
@@ -1,14 +1,24 @@
-// --------  DO NOT EDIT --------
-// This file is autogenerated by buildscripts/gen-constants.go during the release process.
+/*
+ * Minio Cloud Storage, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 
 package main
 
-const (
-	minioVersion    = "UNOFFICIAL.GOGET"
-	minioReleaseTag = "UNOFFICIAL.GOGET"
-	minioCommitID   = "UNOFFICIAL.GOGET"
-)
-
 var (
+	minioVersion       = "UNOFFICIAL.GOGET"
+	minioReleaseTag    = "UNOFFICIAL.GOGET"
+	minioCommitID      = "UNOFFICIAL.GOGET"
 	minioShortCommitID = minioCommitID[:]
 )
diff --git a/buildscripts/gen-constants.go b/buildscripts/gen-ldflags.go
similarity index 51%
rename from buildscripts/gen-constants.go
rename to buildscripts/gen-ldflags.go
index a3fb0a57c..9062ffb6e 100644
--- a/buildscripts/gen-constants.go
+++ b/buildscripts/gen-ldflags.go
@@ -20,50 +20,19 @@ package main
 
 import (
 	"fmt"
-	"net/http"
 	"os"
 	"os/exec"
 	"strings"
-	"text/template"
 	"time"
 )
 
-var constantsTemplate = `// --------  DO NOT EDIT --------
-// This file is autogenerated by buildscripts/gen-constants.go during the release process.
-
-package main
-
-const (
-	minioVersion    = {{if .Version}}"{{.Version}}"{{else}}""{{end}}
-	minioReleaseTag = {{if .ReleaseTag}}"{{.ReleaseTag}}"{{else}}""{{end}}
-	minioCommitID   = {{if .CommitID}}"{{.CommitID}}"{{else}}""{{end}}
-)
-
-var (
-	minioShortCommitID = minioCommitID[:12]
-)
-`
-
-// genConstants generates ‘build-constants.go’.
-func genConstants(version string) {
-	t := template.Must(template.New("constants").Parse(constantsTemplate))
-	constantsFile, e := os.OpenFile("build-constants.go", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
-	if e != nil {
-		fmt.Printf("gen-constants: Unable to create ‘build-constants.go’. Error: %s.\n", e)
-		os.Exit(1)
-	}
-	defer constantsFile.Close()
-
-	e = t.Execute(constantsFile, struct {
-		Version    string
-		ReleaseTag string
-		CommitID   string
-	}{version, releaseTag(version), commitID()})
-
-	if e != nil {
-		fmt.Printf("gen-constants: Unable to generate ‘build-constants.go’. Error: %s.\n", e)
-		os.Exit(1)
-	}
+func genLDFlags(version string) string {
+	var ldflagsStr string
+	ldflagsStr = "\"-X main.minioVersion=" + version + " "
+	ldflagsStr = ldflagsStr + "-X main.minioReleaseTag=" + releaseTag(version) + " "
+	ldflagsStr = ldflagsStr + "-X main.minioCommitID=" + commitID() + " "
+	ldflagsStr = ldflagsStr + "-X main.minioShortCommitID=" + commitID()[:12] + "\""
+	return ldflagsStr
 }
 
 // genReleaseTag prints release tag to the console for easy git tagging.
@@ -97,13 +66,5 @@ func commitID() string {
 }
 
 func main() {
-	// Version is in HTTP TimeFormat.
-	version := time.Now().UTC().Format(http.TimeFormat)
-
-	// generate ‘build-constants.go’ file.
-	genConstants(version)
-
-	fmt.Println("Version: \"" + version + "\"")
-	fmt.Println("Release-Tag: " + releaseTag(version))
-	fmt.Println("Commit-ID: " + commitID())
+	fmt.Println(genLDFlags(time.Now().UTC().Format(time.RFC3339)))
 }
diff --git a/update-main.go b/update-main.go
index b9309b4cd..ea72966b5 100644
--- a/update-main.go
+++ b/update-main.go
@@ -90,7 +90,7 @@ func (u updateMessage) JSON() string {
 }
 
 func getExperimentalUpdate() {
-	current, e := time.Parse(http.TimeFormat, minioVersion)
+	current, e := time.Parse(time.RFC3339, minioVersion)
 	fatalIf(probe.NewError(e), "Unable to parse Version string as time.", nil)
 
 	if current.IsZero() {
@@ -133,7 +133,7 @@ func getExperimentalUpdate() {
 }
 
 func getReleaseUpdate() {
-	current, e := time.Parse(http.TimeFormat, minioVersion)
+	current, e := time.Parse(time.RFC3339, minioVersion)
 	fatalIf(probe.NewError(e), "Unable to parse Version string as time.", nil)
 
 	if current.IsZero() {