feat: use conventional file names by default (#157)

Co-authored-by: Erik Geiser <erik.geiser@redteam-pentesting.de>

cmd/nfpm/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path"
 	"path/filepath"
 
 	"github.com/alecthomas/kingpin"
@@ -25,8 +26,8 @@ var (
 		String()
 
 	pkgCmd = app.Command("pkg", "package based on the config file").Alias("package")
-	target = pkgCmd.Flag("target", "where to save the generated package").
-		Default("/tmp/foo.deb").
+	target = pkgCmd.Flag("target", "where to save the generated package (filename, folder or blank for current folder)").
+		Default("").
 		Short('t').
 		String()
 	packager = pkgCmd.Flag("packager", "which packager implementation to use").
@@ -50,7 +51,6 @@ func main() {
 		if err := doPackage(*config, *target, *packager); err != nil {
 			kingpin.Fatalf(err.Error())
 		}
-		fmt.Printf("created package: %s\n", *target)
 	}
 }
 
@@ -58,12 +58,12 @@ func initFile(config string) error {
 	return ioutil.WriteFile(config, []byte(example), 0600)
 }
 
-func doPackage(path, target, packager string) error {
+func doPackage(configPath, target, packager string) error {
 	if packager == "" {
 		fmt.Printf("guessing packager from target file extension...")
 		packager = filepath.Ext(target)[1:]
 	}
-	config, err := nfpm.ParseFile(path)
+	config, err := nfpm.ParseFile(configPath)
 	if err != nil {
 		return err
 	}
@@ -85,13 +85,36 @@ func doPackage(path, target, packager string) error {
 		return err
 	}
 
+	if target == "" {
+		// if no target was specified create a package in
+		// current directory with a conventional file name
+		target = pkg.ConventionalFileName(info)
+	} else {
+		// if a directory was specified as target, create
+		// a package with conventional file name there
+		var stat os.FileInfo
+		stat, err = os.Stat(target)
+		if err == nil && stat.IsDir() {
+			target = path.Join(target, pkg.ConventionalFileName(info))
+		}
+	}
+
 	f, err := os.Create(target)
 	if err != nil {
 		return err
 	}
 
 	info.Target = target
-	return pkg.Package(info, f)
+
+	err = pkg.Package(info, f)
+	_ = f.Close()
+	if err != nil {
+		os.Remove(target)
+		return err
+	}
+
+	fmt.Printf("created package: %s\n", target)
+	return nil
 }
 
 const example = `# nfpm example config file

deb/deb.go

@@ -44,6 +44,19 @@ var Default = &Deb{}
 // Deb is a deb packager implementation.
 type Deb struct{}
 
+// ConventionalFileName returns a file name according
+// to the conventions for debian packages. See:
+// https://manpages.debian.org/buster/dpkg-dev/dpkg-name.1.en.html
+func (*Deb) ConventionalFileName(info *nfpm.Info) string {
+	arch, ok := archToDebian[info.Arch]
+	if !ok {
+		arch = info.Arch
+	}
+
+	// package_version_architecture.package-type
+	return fmt.Sprintf("%s_%s_%s.deb", info.Name, info.Version, arch)
+}
+
 // Package writes a new deb package to the given writer using the given info.
 func (*Deb) Package(info *nfpm.Info, deb io.Writer) (err error) {
 	arch, ok := archToDebian[info.Arch]

nfpm.go

@@ -81,6 +81,7 @@ func ParseFile(path string) (config Config, err error) {
 // Packager represents any packager implementation.
 type Packager interface {
 	Package(info *Info, w io.Writer) error
+	ConventionalFileName(info *Info) string
 }
 
 // Config contains the top level configuration for packages.

nfpm_test.go

@@ -213,6 +213,10 @@ func TestListFilesToCopy(t *testing.T) {
 
 type fakePackager struct{}
 
+func (*fakePackager) ConventionalFileName(info *Info) string {
+	return ""
+}
+
 func (*fakePackager) Package(info *Info, w io.Writer) error {
 	return nil
 }

rpm/rpm.go

@@ -45,6 +45,15 @@ func ensureValidArch(info *nfpm.Info) *nfpm.Info {
 	return info
 }
 
+// ConventionalFileName returns a file name according
+// to the conventions for RPM packages. See:
+// http://ftp.rpm.org/max-rpm/ch-rpm-file-format.html
+func (*RPM) ConventionalFileName(info *nfpm.Info) string {
+	info = ensureValidArch(info)
+	// name-version-release.architecture.rpm
+	return fmt.Sprintf("%s_%s.%s.rpm", info.Name, info.Version, info.Arch)
+}
+
 // Package writes a new RPM package to the given writer using the given info.
 func (*RPM) Package(info *nfpm.Info, w io.Writer) error {
 	var (