From d7969ce6c0245b987925785193b6ba44172bb04f Mon Sep 17 00:00:00 2001
From: Sascha Grunert <sgrunert@redhat.com>
Date: Thu, 14 Jul 2022 14:08:41 +0200
Subject: [PATCH] Allow the override of all `version` package variables

This now makes it possible to override all variables via the `-X`
ldflag, for example:

```go
package main

import (
	"fmt"

	"sigs.k8s.io/release-utils/version"
)

func main() {
	v := version.GetVersionInfo()
	fmt.Print(v.String())
}
```

```
> go run -ldflags '\
    -X sigs.k8s.io/release-utils/version.gitVersion=1 \
    -X sigs.k8s.io/release-utils/version.gitCommit=2 \
    -X sigs.k8s.io/release-utils/version.gitTreeState=3 \
    -X sigs.k8s.io/release-utils/version.buildDate=4 \
    -X sigs.k8s.io/release-utils/version.goVersion=5 \
    -X sigs.k8s.io/release-utils/version.compiler=6 \
    -X sigs.k8s.io/release-utils/version.platform=7' \
    main.go
GitVersion:    1
GitCommit:     2
GitTreeState:  3
BuildDate:     4
GoVersion:     5
Compiler:      6
Platform:      7
```

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
---
 version/version.go | 46 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 11 deletions(-)

diff --git a/version/version.go b/version/version.go
index d44c9c3..46dd1dc 100644
--- a/version/version.go
+++ b/version/version.go
@@ -47,6 +47,12 @@ var (
 	buildDate = unknown
 	// flag to print the ascii name banner
 	asciiName = "true"
+	// goVersion is the used golang version.
+	goVersion = unknown
+	// compiler is the used golang compiler.
+	compiler = unknown
+	// platform is the used os/arch identifier.
+	platform = unknown
 )
 
 type Info struct {
@@ -64,14 +70,6 @@ type Info struct {
 	Description string `json:"-"`
 }
 
-func init() {
-	buildInfo := getBuildInfo()
-	gitVersion = getGitVersion(buildInfo)
-	gitCommit = getCommit(buildInfo)
-	gitTreeState = getDirty(buildInfo)
-	buildDate = getBuildDate(buildInfo)
-}
-
 func getBuildInfo() *debug.BuildInfo {
 	bi, ok := debug.ReadBuildInfo()
 	if !ok {
@@ -131,15 +129,41 @@ func getKey(bi *debug.BuildInfo, key string) string {
 
 // GetVersionInfo represents known information on how this binary was built.
 func GetVersionInfo() Info {
+	buildInfo := getBuildInfo()
+	gitVersion = getGitVersion(buildInfo)
+	if gitCommit == unknown {
+		gitCommit = getCommit(buildInfo)
+	}
+
+	if gitTreeState == unknown {
+		gitTreeState = getDirty(buildInfo)
+	}
+
+	if buildDate == unknown {
+		buildDate = getBuildDate(buildInfo)
+	}
+
+	if goVersion == unknown {
+		goVersion = runtime.Version()
+	}
+
+	if compiler == unknown {
+		compiler = runtime.Compiler
+	}
+
+	if platform == unknown {
+		platform = fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH)
+	}
+
 	return Info{
 		ASCIIName:    asciiName,
 		GitVersion:   gitVersion,
 		GitCommit:    gitCommit,
 		GitTreeState: gitTreeState,
 		BuildDate:    buildDate,
-		GoVersion:    runtime.Version(),
-		Compiler:     runtime.Compiler,
-		Platform:     fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
+		GoVersion:    goVersion,
+		Compiler:     compiler,
+		Platform:     platform,
 	}
 }