Add `build.go`

README.md

@@ -43,11 +43,10 @@ Restic is a program that does backups right. The design goals are:
 Building
 ========
 
-Install Go/Golang (at least version 1.3), then run `make`, afterwards you'll
-find the binary in the current directory:
+Install Go/Golang (at least version 1.3), then run `go run build.go`,
+afterwards you'll find the binary in the current directory:
 
-    $ make
-    [...]
+    $ go run build.go
 
     $ ./restic --help
     Usage:

build.go

@@ -0,0 +1,256 @@
+// +build ignore
+
+package main
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+var (
+	verbose    bool
+	keepGopath bool
+)
+
+const timeFormat = "2006-01-02 15:04:05"
+
+// specialDir returns true if the file begins with a special character ('.' or '_').
+func specialDir(name string) bool {
+	if name == "." {
+		return false
+	}
+
+	base := filepath.Base(name)
+	return base[0] == '_' || base[0] == '.'
+}
+
+// updateGopath builds a valid GOPATH at dst, with all Go files in src/ copied
+// to dst/prefix/, so calling
+//
+//   updateGopath("/tmp/gopath", "/home/u/restic", "github.com/restic/restic")
+//
+// with "/home/u/restic" containing the file "foo.go" yields the following tree
+// at "/tmp/gopath":
+//
+//   /tmp/gopath
+//   └── src
+//       └── github.com
+//           └── restic
+//               └── restic
+//                   └── foo.go
+func updateGopath(dst, src, prefix string) error {
+	return filepath.Walk(src, func(name string, fi os.FileInfo, err error) error {
+		if specialDir(name) {
+			if fi.IsDir() {
+				return filepath.SkipDir
+			}
+
+			return nil
+		}
+
+		if fi.IsDir() {
+			return nil
+		}
+
+		ext := path.Ext(name)
+		if ext != ".go" && ext != ".s" {
+			return nil
+		}
+
+		intermediatePath, err := filepath.Rel(src, name)
+		if err != nil {
+			return err
+		}
+
+		fileSrc := filepath.Join(src, intermediatePath)
+		fileDst := filepath.Join(dst, "src", prefix, intermediatePath)
+
+		return copyFile(fileDst, fileSrc)
+	})
+}
+
+// copyFile creates dst from src, preserving file attributes and timestamps.
+func copyFile(dst, src string) error {
+	fi, err := os.Stat(src)
+	if err != nil {
+		return err
+	}
+
+	fsrc, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+
+	if err = os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		fmt.Printf("MkdirAll(%v)\n", filepath.Dir(dst))
+		return err
+	}
+
+	fdst, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+
+	if _, err = io.Copy(fdst, fsrc); err != nil {
+		return err
+	}
+
+	if err == nil {
+		err = fsrc.Close()
+	}
+
+	if err == nil {
+		err = fdst.Close()
+	}
+
+	if err == nil {
+		err = os.Chmod(dst, fi.Mode())
+	}
+
+	if err == nil {
+		err = os.Chtimes(dst, fi.ModTime(), fi.ModTime())
+	}
+
+	return nil
+}
+
+// die prints the message with fmt.Fprintf() to stderr and exits with an error
+// code.
+func die(message string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, message, args...)
+	os.Exit(1)
+}
+
+func showUsage(output io.Writer) {
+	fmt.Fprintf(output, "USAGE: go run build.go OPTIONS\n")
+	fmt.Fprintf(output, "\n")
+	fmt.Fprintf(output, "OPTIONS:\n")
+	fmt.Fprintf(output, "  -v     --verbose   output more messages\n")
+}
+
+func verbosePrintf(message string, args ...interface{}) {
+	if !verbose {
+		return
+	}
+
+	fmt.Printf(message, args...)
+}
+
+// cleanEnv returns a clean environment with GOPATH and GOBIN removed (if
+// present).
+func cleanEnv() (env []string) {
+	for _, v := range os.Environ() {
+		if strings.HasPrefix(v, "GOPATH=") || strings.HasPrefix(v, "GOBIN=") {
+			continue
+		}
+
+		env = append(env, v)
+	}
+
+	return env
+}
+
+// build runs "go build args..." with GOPATH set to gopath.
+func build(gopath string, args ...string) error {
+	args = append([]string{"build"}, args...)
+	cmd := exec.Command("go", args...)
+	cmd.Env = append(cleanEnv(), "GOPATH="+gopath)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	verbosePrintf("go %s\n", args)
+
+	return cmd.Run()
+}
+
+// getVersion returns a version string, either from the file VERSION in the
+// current directory or from git.
+func getVersion() string {
+	v, err := ioutil.ReadFile("VERSION")
+	version := strings.TrimSpace(string(v))
+	if err == nil {
+		verbosePrintf("version from file 'VERSION' is %s\n", version)
+		return version
+	}
+
+	return gitVersion()
+}
+
+// gitVersion returns a version string that identifies the currently checked
+// out git commit.
+func gitVersion() string {
+	cmd := exec.Command("git", "describe",
+		"--long", "--tags", "--dirty", "--always")
+	out, err := cmd.Output()
+	if err != nil {
+		die("git describe returned error: %v\n", err)
+	}
+
+	version := strings.TrimSpace(string(out))
+	verbosePrintf("git version is %s\n", version)
+	return version
+}
+
+func main() {
+	for _, arg := range os.Args[1:] {
+		switch arg {
+		case "-v", "--verbose":
+			verbose = true
+		case "-k", "--keep-gopath":
+			keepGopath = true
+		case "-h":
+			showUsage(os.Stdout)
+		default:
+			fmt.Fprintf(os.Stderr, "Error: unknown option %q\n\n", arg)
+			showUsage(os.Stderr)
+			os.Exit(1)
+		}
+	}
+
+	root, err := os.Getwd()
+	if err != nil {
+		die("Getwd(): %v\n", err)
+	}
+
+	gopath, err := ioutil.TempDir("", "restic-build-")
+	if err != nil {
+		die("TempDir(): %v\n", err)
+	}
+
+	verbosePrintf("create GOPATH at %v\n", gopath)
+	if err = updateGopath(gopath, root, "github.com/restic/restic"); err != nil {
+		die("copying files from %v to %v failed: %v\n", root, gopath, err)
+	}
+
+	vendor := filepath.Join(root, "Godeps", "_workspace", "src")
+	if err = updateGopath(gopath, vendor, ""); err != nil {
+		die("copying files from %v to %v failed: %v\n", root, gopath, err)
+	}
+
+	version := getVersion()
+	compileTime := time.Now().Format(timeFormat)
+	args := []string{
+		"-tags", "release",
+		"-ldflags", fmt.Sprintf(`-s -X main.version %q -X main.compiledAt %q`, version, compileTime),
+		"-o", "restic", "github.com/restic/restic/cmd/restic",
+	}
+	err = build(gopath, args...)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "build failed: %v\n", err)
+	}
+
+	if !keepGopath {
+		verbosePrintf("remove %v\n", gopath)
+		if err = os.RemoveAll(gopath); err != nil {
+			die("remove GOPATH at %s failed: %v\n", err)
+		}
+	} else {
+		fmt.Printf("leaving temporary GOPATH at %v\n", gopath)
+	}
+}

cmd/restic/Makefile

@@ -1,18 +0,0 @@
-.PHONY: all clean debug
-
-# include config file if it exists
--include $(CURDIR)/config.mk
-
-all: restic
-
-debug: restic.debug
-
-restic: $(wildcard *.go) $(wildcard ../../*.go) $(wildcard ../../*/*.go)
-	go build -a
-
-restic.debug: $(wildcard *.go) $(wildcard ../../*.go) $(wildcard ../../*/*.go)
-	go build -a -tags debug -o restic.debug
-
-clean:
-	go clean
-	rm -f restic restic.debug

cmd/restic/cmd_version.go

@@ -18,7 +18,8 @@ func init() {
 }
 
 func (cmd CmdVersion) Execute(args []string) error {
-	fmt.Printf("restic %s on %v\n", version, runtime.Version())
+	fmt.Printf("restic %s\ncompiled at %s with %v\n",
+		version, compiledAt, runtime.Version())
 
 	return nil
 }

cmd/restic/global.go

@@ -17,6 +17,7 @@ import (
 )
 
 var version = "compiled manually"
+var compiledAt = "unknown time"
 
 type GlobalOptions struct {
 	Repo     string `short:"r" long:"repo"                      description:"Repository directory to backup to/restore from"`

cmd/restic/version.sh

@@ -1,13 +0,0 @@
-#!/bin/sh
-
-VERSION=$(git log --max-count=1 --pretty='%ad-%h' --date=short HEAD 2>/dev/null)
-
-if [ -n "$VERSION" ]; then
-    if ! sh -c "git diff -s --exit-code && git diff --cached -s --exit-code"; then
-        VERSION+="+"
-    fi
-else
-    VERSION="unknown version"
-fi
-
-echo $VERSION