Try a new version-expose scheme using go:generate

Tarifut · Dec 2, 2016 · 09bfd15 · 09bfd15
1 parent 9bb02f8
commit 09bfd15
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Showing 3 changed files with 75 additions and 2 deletions.
diff --git a/main.go b/main.go
@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"github.com/aws/aws-sdk-go/service/s3/s3manager"
+	"github.com/peakgames/s5cmd/version"
 	"log"
 	"math"
 	"os"
@@ -15,8 +16,10 @@ import (
 	"time"
 )
 
+//go:generate go run version/cmd/generate.go
 var (
-	GitSummary, GitBranch string
+	GitSummary = version.GitSummary
+	GitBranch  = version.GitBranch
 )
 
 func printOps(name string, counter uint64, elapsed time.Duration, extra string) {
@@ -66,7 +69,11 @@ func main() {
 	flag.Parse()
 
 	if *version {
-		fmt.Printf("s5cmd version %s (from branch %s)\n", GitSummary, GitBranch)
+		fmt.Printf("s5cmd version %s", GitSummary)
+		if GitBranch != "" {
+			fmt.Printf(" (from branch %s)", GitBranch)
+		}
+		fmt.Print("\n")
 		os.Exit(0)
 	}
 

diff --git a/version/cmd/generate.go b/version/cmd/generate.go
@@ -0,0 +1,58 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+func mustRunGetResult(cmd string, arg ...string) string {
+	var buf bytes.Buffer
+
+	c := exec.Command(cmd)
+	c.Args = append(c.Args, arg...)
+	c.Stdout = &buf
+	c.Stderr = os.Stderr
+	err := c.Run()
+
+	if err != nil {
+		log.Fatal(err)
+		return ""
+	}
+
+	return strings.Trim(buf.String(), "\n\r ")
+}
+
+func commandToConst(name, command string, args []string) string {
+	data := mustRunGetResult(command, args...)
+
+	ret := "\n// " + name + " is the output of \"" + command + " " + strings.Join(args, " ") + "\"\n"
+	ret += "const " + name + ` = "` + data + `"` + "\n"
+
+	return ret
+}
+
+const destinationFile = "version/version.go"
+
+func main() {
+	summary := commandToConst("GitSummary", "git", strings.Split("describe --tags --dirty --always", " "))
+	branch := commandToConst("GitBranch", "git", strings.Split("symbolic-ref -q --short HEAD", " "))
+
+	timestamp := time.Now().Format(time.UnixDate)
+
+	b := bytes.NewBuffer(nil)
+	fmt.Fprint(b, `// This package is auto-generated using version/cmd/generate.go
+package version
+
+// AUTO-GENERATED. DO NOT EDIT
+// `+timestamp+"\n"+summary+branch+"\n")
+	log.Printf("Writing %s...\n", destinationFile)
+	if err := ioutil.WriteFile(destinationFile, b.Bytes(), 0644); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/version/version.go b/version/version.go
@@ -0,0 +1,8 @@
+// This package will be auto-generated using version/cmd/generate.go
+package version
+
+// GitSummary will be the output of "git describe --tags --dirty --always"
+const GitSummary = "v0.0"
+
+// GitBranch will be the output of "git symbolic-ref -q --short HEAD"
+const GitBranch = ""