Create version package, so it can be used outside of main

.goreleaser.yml

@@ -10,7 +10,7 @@ builds:
       - CGO_ENABLED=0
     ldflags:
       # gitTag set from a generated file (see ./tag_release.sh)
-      - -s -w -X main.builtAt={{.Date}} -X main.gitCommit={{.Commit}}
+      - -s -w -X github.com/weaveworks/eksctl/pkg/version.builtAt={{.Date}} -X github.com/weaveworks/eksctl/pkg/version.gitCommit={{.Commit}}
     goos:
       - windows
       - darwin

Makefile

@@ -1,6 +1,8 @@
 built_at := $(shell date +%s)
 git_commit := $(shell git describe --dirty --always)
 
+version_pkg := github.com/weaveworks/eksctl/pkg/version
+
 EKSCTL_BUILD_IMAGE ?= weaveworks/eksctl:build
 EKSCTL_IMAGE ?= weaveworks/eksctl:latest
 
@@ -20,7 +22,7 @@ install-build-deps: ## Install dependencies (packages and tools)
 
 .PHONY: build
 build: ## Build eksctl
-	@go build -ldflags "-X main.gitCommit=$(git_commit) -X main.builtAt=$(built_at)" ./cmd/eksctl
+	@go build -ldflags "-X $(version_pkg).gitCommit=$(git_commit) -X $(version_pkg).builtAt=$(built_at)" ./cmd/eksctl
 
 ##@ Testing & CI
 

cmd/eksctl/version.go

@@ -3,26 +3,18 @@ package main
 import (
 	"github.com/spf13/cobra"
 
+	"github.com/weaveworks/eksctl/pkg/version"
+
 	"github.com/kubicorn/kubicorn/pkg/logger"
 )
 
-//go:generate go run version_generate.go
-
 func versionCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "version",
 		Short: "Output the version of eksctl",
 		Run: func(_ *cobra.Command, _ []string) {
-			versionInfo := map[string]string{
-				"builtAt":   builtAt,
-				"gitCommit": gitCommit,
-			}
-
-			if gitTag != "" {
-				versionInfo["gitTag"] = gitTag
-			}
 
-			logger.Info("versionInfo = %#v", versionInfo)
+			logger.Info("%#v", version.Get())
 		},
 	}
 }

pkg/version/norelease.go

@@ -0,0 +1,7 @@
+// +build !release
+
+package version
+
+var (
+	builtAt, gitCommit, gitTag string
+)

pkg/version/release.go

@@ -0,0 +1,10 @@
+// +build release
+
+package version
+
+// This file was generated by release_generate.go; DO NOT EDIT.
+
+// Values of builtAt and gitCommit will be set by the linker.
+var builtAt = ""
+var gitCommit = ""
+var gitTag = "0.1.11"

pkg/version/release_generate.go

@@ -0,0 +1,37 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"io/ioutil"
+	"log"
+	"os"
+
+	. "github.com/dave/jennifer/jen"
+)
+
+func main() {
+	f := NewFile("version")
+
+	f.Comment("This file was generated by release_generate.go; DO NOT EDIT.")
+	f.Line()
+
+	f.Comment("Values of builtAt and gitCommit will be set by the linker.")
+	f.Var().Id("builtAt").Op("=").Lit("")
+	f.Var().Id("gitCommit").Op("=").Lit("")
+
+	gitTag := os.Getenv("RELEASE_GIT_TAG")
+	f.Var().Id("gitTag").Op("=").Lit(gitTag)
+
+	buf := &bytes.Buffer{}
+	if _, err := buf.WriteString("// +build release\n\n"); err != nil {
+		log.Fatal(err.Error())
+	}
+	if err := f.Render(buf); err != nil {
+		log.Fatal(err.Error())
+	}
+	if err := ioutil.WriteFile("release.go", buf.Bytes(), 0644); err != nil {
+		log.Fatal(err.Error())
+	}
+}

pkg/version/version.go

@@ -0,0 +1,31 @@
+package version
+
+import (
+	"encoding/json"
+)
+
+//go:generate go run ./release_generate.go
+
+// Info hold version information
+type Info struct {
+	BuiltAt   string
+	GitCommit string `json:",omitempty"`
+	GitTag    string `json:",omitempty"`
+}
+
+var info = Info{
+	BuiltAt:   builtAt,
+	GitCommit: gitCommit,
+	GitTag:    gitTag,
+}
+
+// Get return version Info struct
+func Get() Info { return info }
+
+// String return version info as JSON
+func String() string {
+	if data, err := json.Marshal(info); err == nil {
+		return string(data)
+	}
+	return ""
+}