From 7557c0d7a00e9c73056ae202264893daf8533aa6 Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Tue, 6 Apr 2021 10:57:57 +0200
Subject: [PATCH] safcm: add "version" sub-command

Embed current Git and Go version at build time.
---
 Makefile             |  8 +++++++-
 cmd/safcm/main.go    |  6 ++++++
 cmd/safcm/version.go | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 cmd/safcm/version.go

diff --git a/Makefile b/Makefile
index 8ccec9d..ddde397 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,15 @@
+LDFLAGS = '\
+    -X "main.versionGit=$(shell git describe --long --tags --dirty --always)" \
+    -X "main.versionGo=$(shell go version)" \
+'
+
+
 all: safcm
 
 safcm:
 	go fmt ./...
 	cd cmd/safcm-remote && ./build.sh
-	go build -race ruderich.org/simon/safcm/cmd/safcm
+	go build -ldflags $(LDFLAGS) -race ruderich.org/simon/safcm/cmd/safcm
 	@# For proper permissions after initial clone with a strict umask
 	cd cmd/safcm/testdata/project && ../../../../safcm fixperms 2> /dev/null
 
diff --git a/cmd/safcm/main.go b/cmd/safcm/main.go
index 5916b84..ca037c5 100644
--- a/cmd/safcm/main.go
+++ b/cmd/safcm/main.go
@@ -28,6 +28,7 @@ func usage() {
 	log.SetFlags(0)
 	log.Fatalf("usage: %[1]s sync [<options>] <host|group...>\n"+
 		"       %[1]s fixperms\n"+
+		"       %[1]s version\n"+
 		"", os.Args[0])
 }
 
@@ -45,6 +46,11 @@ func main() {
 			usage()
 		}
 		err = MainFixperms()
+	case "version":
+		if len(os.Args) != 2 {
+			usage()
+		}
+		err = MainVersion()
 	default:
 		usage()
 	}
diff --git a/cmd/safcm/version.go b/cmd/safcm/version.go
new file mode 100644
index 0000000..f1ad1b3
--- /dev/null
+++ b/cmd/safcm/version.go
@@ -0,0 +1,35 @@
+// "version" sub-command: display version information
+
+// Copyright (C) 2021  Simon Ruderich
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"fmt"
+)
+
+// Set via -ldflags -X during build
+var (
+	versionGit string
+	versionGo  string
+)
+
+func MainVersion() error {
+	fmt.Printf("safcm %s, compiled with %s\n",
+		versionGit,
+		versionGo)
+	return nil
+}
-- 
2.45.2