X-Git-Url: https://ruderich.org/simon/gitweb/?p=nsscash%2Fnsscash.git;a=blobdiff_plain;f=file.go;h=3884bba8b6ae3c4f0e6d86f26d796fd5fcac0952;hp=0857dd50f14dde2fa1d0a7507fbe9e3ac17ad499;hb=HEAD;hpb=6383e468f1d5b281159cd46d800204a1aa718cd2

diff --git a/file.go b/file.go
index 0857dd5..3884bba 100644
--- a/file.go
+++ b/file.go
@@ -1,6 +1,6 @@
 // Download and write files atomically to the file system
 
-// 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
@@ -30,6 +30,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/google/renameio"
 	"github.com/pkg/errors"
 )
 
@@ -89,11 +90,17 @@ func fetchFile(file *File, state *State) error {
 		t = zero // force download
 	}
 
-	status, body, err := fetchIfModified(file.Url, &t)
+	oldT := t
+	status, body, err := fetchIfModified(file.Url,
+		file.Username, file.Password, file.CA, &t)
 	if err != nil {
 		return err
 	}
 	if status == http.StatusNotModified {
+		if oldT.IsZero() {
+			return fmt.Errorf("status code 304 " +
+				"but did not send If-Modified-Since")
+		}
 		log.Printf("%q -> %q: not modified", file.Url, file.Path)
 		return nil
 	}
@@ -158,28 +165,22 @@ func deployFile(file *File) error {
 		return fmt.Errorf("refusing to write empty file")
 	}
 
-	// Write the file in an atomic fashion by creating a temporary file
-	// and renaming it over the target file
-
-	dir := filepath.Dir(file.Path)
-	name := filepath.Base(file.Path)
-
-	f, err := ioutil.TempFile(dir, "tmp-"+name+"-")
+	f, err := renameio.TempFile(filepath.Dir(file.Path), file.Path)
 	if err != nil {
 		return err
 	}
-	defer os.Remove(f.Name())
-	defer f.Close()
+	defer f.Cleanup()
 
-	// Apply permissions/user/group from the target file, use Stat instead
-	// of Lstat as only the target's permissions are relevant
+	// Apply permissions/user/group from the target file but remove the
+	// write permissions to discourage manual modifications, use Stat
+	// instead of Lstat as only the target's permissions are relevant
 	stat, err := os.Stat(file.Path)
 	if err != nil {
 		// We do not create the path if it doesn't exist, because we
 		// do not know the proper permissions
 		return errors.Wrapf(err, "file.path %q must exist", file.Path)
 	}
-	err = f.Chmod(stat.Mode())
+	err = f.Chmod(stat.Mode() & ^os.FileMode(0222)) // remove write perms
 	if err != nil {
 		return err
 	}
@@ -197,9 +198,9 @@ func deployFile(file *File) error {
 	if err != nil {
 		return err
 	}
-	err = f.Sync()
+	err = f.CloseAtomicallyReplace()
 	if err != nil {
 		return err
 	}
-	return os.Rename(f.Name(), file.Path)
+	return syncPath(filepath.Dir(file.Path))
 }