Add --version flag

This allows to identify the version of a Ceres executable build.

2 files changed, 18 insertions, 5 deletions

diff --git a/flags.go b/flags.go
index e7ff85e..862cffa 100644
--- a/flags.go
+++ b/flags.go
@@ -7,15 +7,18 @@ import (
 
 const help = `Ceres - Recipe server for local networks
 
-Usage: ceres [-h | --help]
+Usage: ceres [-h | --help] [-v | --version]
 
   -h, --help                 show this help page and exit
+  -v, --version              print version information
 `
 
-func parseFlags() {
+var printVersion bool
+
+func init() {
+	flag.BoolVar(&printVersion, "version", false, "print version information")
+	flag.BoolVar(&printVersion, "v", false, "print version information")
 	flag.Usage = func() {
 		fmt.Fprintf(flag.CommandLine.Output(), help)
 	}
-
-	flag.Parse()
 }
diff --git a/main.go b/main.go
index 1071aef..2c39239 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,8 @@ package main
 import (
 	"context"
 	"embed"
+	"flag"
+	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -17,7 +19,15 @@ import (
 )
 
 func main() {
-	parseFlags()
+	flag.Parse()
+
+	if printVersion {
+		if gitDescribe == "" {
+			log.Fatal("This build has no version information")
+		}
+		fmt.Println(gitDescribe)
+		os.Exit(0)
+	}
 
 	model.InitStorage()
 	defer model.RemoveStorage()