X-Git-Url: https://ruderich.org/simon/gitweb/?p=nsscash%2Fnsscash.git;a=blobdiff_plain;f=main.go;h=7a7d8b0da8e6855b8545c609f6169184819db7ae;hp=6322157f2ca9564d6523606095ee0967fd2d8daa;hb=HEAD;hpb=33e06a7ef39ce42d9933ca9106a453daa7eb58ac

diff --git a/main.go b/main.go
index 6322157..7a7d8b0 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,6 @@
 // Main file for nsscash
 
-// Copyright (C) 2019  Simon Ruderich
+// Copyright (C) 2019-2021  Simon Ruderich
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU Affero General Public License as published by
@@ -24,6 +24,9 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"path/filepath"
+
+	"github.com/google/renameio"
 )
 
 func main() {
@@ -49,7 +52,10 @@ func main() {
 			break
 		}
 
-		mainFetch(args[1])
+		err := mainFetch(args[1])
+		if err != nil {
+			log.Fatal(err)
+		}
 		return
 
 	case "convert":
@@ -57,7 +63,10 @@ func main() {
 			break
 		}
 
-		mainConvert(args[1], args[2], args[3])
+		err := mainConvert(args[1], args[2], args[3])
+		if err != nil {
+			log.Fatal(err)
+		}
 		return
 	}
 
@@ -65,77 +74,86 @@ func main() {
 	os.Exit(1)
 }
 
-func mainFetch(cfgPath string) {
-		cfg, err := LoadConfig(cfgPath)
+func mainFetch(cfgPath string) error {
+	cfg, err := LoadConfig(cfgPath)
+	if err != nil {
+		return err
+	}
+	state, err := LoadState(cfg.StatePath)
+	if err != nil {
+		return err
+	}
+	err = handleFiles(cfg, state)
+	if err != nil {
+		return err
+	}
+	// NOTE: Make sure to call WriteState() only if there were no
+	// errors (see WriteState() and README)
+	err = WriteState(cfg.StatePath, state)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func mainConvert(typ, srcPath, dstPath string) error {
+	var t FileType
+	err := t.UnmarshalText([]byte(typ))
+	if err != nil {
+		return err
+	}
+
+	src, err := ioutil.ReadFile(srcPath)
+	if err != nil {
+		return err
+	}
+	var x bytes.Buffer
+	if t == FileTypePlain {
+		x.Write(src)
+	} else if t == FileTypePasswd {
+		pws, err := ParsePasswds(bytes.NewReader(src))
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
-		state, err := LoadState(cfg.StatePath)
+		err = SerializePasswds(&x, pws)
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
-		err = handleFiles(cfg, state)
+	} else if t == FileTypeGroup {
+		grs, err := ParseGroups(bytes.NewReader(src))
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
-		// NOTE: Make sure to call WriteState() only if there were no
-		// errors (see WriteState() and README)
-		err = WriteState(cfg.StatePath, state)
+		err = SerializeGroups(&x, grs)
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
-}
+	} else {
+		return fmt.Errorf("unsupported file type %v", t)
+	}
 
-func mainConvert(typ, srcPath, dstPath string) {
-		var t FileType
-		err := t.UnmarshalText([]byte(typ))
-		if err != nil {
-			log.Fatal(err)
-		}
+	// We must create the file first or deployFile() will abort; this is
+	// ugly because deployFile() already performs an atomic replacement
+	// but the simplest solution with the least duplicate code
+	f, err := renameio.TempFile(filepath.Dir(dstPath), dstPath)
+	if err != nil {
+		return err
+	}
+	defer f.Cleanup()
 
-		src, err := ioutil.ReadFile(srcPath)
-		if err != nil {
-			log.Fatal(err)
-		}
-		var x bytes.Buffer
-		if t == FileTypePlain {
-			x.Write(src)
-		} else if t == FileTypePasswd {
-			pws, err := ParsePasswds(bytes.NewReader(src))
-			if err != nil {
-				log.Fatal(err)
-			}
-			err = SerializePasswds(&x, pws)
-			if err != nil {
-				log.Fatal(err)
-			}
-		} else if t == FileTypeGroup {
-			grs, err := ParseGroups(bytes.NewReader(src))
-			if err != nil {
-				log.Fatal(err)
-			}
-			err = SerializeGroups(&x, grs)
-			if err != nil {
-				log.Fatal(err)
-			}
-		} else {
-			log.Fatalf("unsupported file type %v", t)
-		}
+	err = deployFile(&File{
+		Type: t,
+		Url:  srcPath,
+		Path: f.Name(),
+		body: x.Bytes(),
+	})
+	if err != nil {
+		return err
+	}
 
-		// We must create the file first or deployFile() will abort
-		f, err := os.Create(dstPath)
-		if err != nil {
-			log.Fatal(err)
-		}
-		f.Close()
-
-		err = deployFile(&File{
-			Type: t,
-			Url:  srcPath,
-			Path: dstPath,
-			body: x.Bytes(),
-		})
-		if err != nil {
-			log.Fatal(err)
-		}
+	err = f.CloseAtomicallyReplace()
+	if err != nil {
+		return err
+	}
+	return syncPath(filepath.Dir(dstPath))
 }