From 5ed20e47f74d8571f52d3d184527b355308b872c Mon Sep 17 00:00:00 2001
From: Dave Henderson <dhenderson@gmail.com>
Date: Mon, 11 Apr 2016 13:35:44 -0400
Subject: [PATCH] Setting the version at build time from the latest tag

Signed-off-by: Dave Henderson <dhenderson@gmail.com>
---
 Makefile           | 5 ++++-
 README.md          | 9 ++++-----
 main.go            | 6 ++----
 version/version.go | 8 ++++++++
 4 files changed, 18 insertions(+), 10 deletions(-)
 create mode 100644 version/version.go

diff --git a/Makefile b/Makefile
index dcbbf56cb..8d91d2646 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,9 @@ GO := go
 PKG_NAME := gomplate
 PREFIX := .
 
+COMMIT_FLAG := -X `go list ./version`.GitCommit=`git rev-parse --short HEAD 2>/dev/null`
+VERSION_FLAG := -X `go list ./version`.Version=`git describe --abbrev=0 --tags $(git rev-list --tags --max-count=1) 2>/dev/null | sed 's/v\(.*\)/\1/'`
+
 define gocross
 	GOOS=$(1) GOARCH=$(2) \
 		$(GO) build \
@@ -21,7 +24,7 @@ build-x: $(shell find . -type f -name '*.go')
 	$(call gocross,windows,386)
 
 $(PREFIX)/bin/$(PKG_NAME)$(call extension,$(GOOS)): $(shell find . -type f -name '*.go')
-	$(GO) build -o $@
+	$(GO) build -ldflags "$(COMMIT_FLAG) $(VERSION_FLAG)" -o $@
 
 build: $(PREFIX)/bin/$(PKG_NAME)$(call extension,$(GOOS))
 
diff --git a/README.md b/README.md
index 4eba577ba..8120c709c 100644
--- a/README.md
+++ b/README.md
@@ -201,11 +201,10 @@ _Note:_ it's important for the `if`/`else`/`end` keywords to appear on the same
 
 Right now the release process is semi-automatic.
 
-1. Update the Version `const` in `main.go`
-2. Create a release tag: `git tag -a v0.0.9 -m "Releasing v0.9.9"`
-3. Build binaries: `make build-x`
-4. _(optional)_ compress the binaries with `upx` (may not work for all architectures)
-5. Create a release in [github](https://github.com/hairyhenderson/gomplate/releases)!
+1. Create a release tag: `git tag -a v0.0.9 -m "Releasing v0.9.9"`
+2. Build binaries: `make build-x`
+3. _(optional)_ compress the binaries with `upx` (may not work for all architectures)
+4. Create a release in [github](https://github.com/hairyhenderson/gomplate/releases)!
 
 ## License
 
diff --git a/main.go b/main.go
index a0109b3b9..0df87d5d6 100644
--- a/main.go
+++ b/main.go
@@ -9,18 +9,16 @@ import (
 	"os"
 
 	"github.com/hairyhenderson/gomplate/aws"
+	"github.com/hairyhenderson/gomplate/version"
 
 	"text/template"
 )
 
-// version
-const Version = "0.2.2"
-
 func init() {
 	ver := flag.Bool("v", false, "Print version and exit")
 	flag.Parse()
 	if *ver {
-		fmt.Println(Version)
+		fmt.Println(version.Version)
 		os.Exit(0)
 	}
 }
diff --git a/version/version.go b/version/version.go
new file mode 100644
index 000000000..cf5075c2d
--- /dev/null
+++ b/version/version.go
@@ -0,0 +1,8 @@
+package version
+
+var (
+	// Version will be overwritten automatically by the build
+	Version = "0.0.0"
+	// GitCommit will be overwritten automatically by the build
+	GitCommit = "HEAD"
+)