fix(system): write all files atomically

initialize/config.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"log"
-	"path"
 
 	"github.com/coreos/coreos-cloudinit/third_party/launchpad.net/goyaml"
 
@@ -221,11 +220,11 @@ func Apply(cfg CloudConfig, env *Environment) error {
 	}
 
 	for _, file := range cfg.WriteFiles {
-		file.Path = path.Join(env.Root(), file.Path)
-		if err := system.WriteFile(&file); err != nil {
+		path, err := system.WriteFile(&file, env.Root())
+		if err != nil {
 			return err
 		}
-		log.Printf("Wrote file %s to filesystem", file.Path)
+		log.Printf("Wrote file %s to filesystem", path)
 	}
 
 	commands := make(map[string]string, 0)

initialize/manage_etc_hosts_test.go

@@ -50,9 +50,7 @@ func TestEtcHostsWrittenToDisk(t *testing.T) {
 		t.Fatalf("manageEtcHosts returned nil file unexpectedly")
 	}
 
-	f.Path = path.Join(dir, f.Path)
-
-	if err := system.WriteFile(f); err != nil {
+	if _, err := system.WriteFile(f, dir); err != nil {
 		t.Fatalf("Error writing EtcHosts: %v", err)
 	}
 

initialize/oem_test.go

@@ -31,8 +31,7 @@ func TestOEMReleaseWrittenToDisk(t *testing.T) {
 		t.Fatalf("OEMRelease returned nil file unexpectedly")
 	}
 
-	f.Path = path.Join(dir, f.Path)
-	if err := system.WriteFile(f); err != nil {
+	if _, err := system.WriteFile(f, dir); err != nil {
 		t.Fatalf("Writing of OEMRelease failed: %v", err)
 	}
 

initialize/update_test.go

@@ -205,8 +205,7 @@ func TestUpdateConfWrittenToDisk(t *testing.T) {
 			t.Fatal("Unexpectedly got nil updateconfig file")
 		}
 
-		f.Path = path.Join(dir, f.Path)
-		if err := system.WriteFile(f); err != nil {
+		if _, err := system.WriteFile(f, dir); err != nil {
 			t.Fatalf("Error writing update config: %v", err)
 		}
 

initialize/workspace.go

@@ -3,6 +3,7 @@ package initialize
 import (
 	"io/ioutil"
 	"path"
+	"strings"
 
 	"github.com/coreos/coreos-cloudinit/system"
 )
@@ -28,21 +29,23 @@ func PersistScriptInWorkspace(script system.Script, workspace string) (string, e
 	}
 	tmp.Close()
 
+	relpath := strings.TrimPrefix(tmp.Name(), workspace)
+
 	file := system.File{
-		Path: tmp.Name(),
+		Path:               relpath,
 		RawFilePermissions: "0744",
-		Content: string(script),
+		Content:            string(script),
 	}
 
-	err = system.WriteFile(&file)
-	return file.Path, err
+	return system.WriteFile(&file, workspace)
 }
 
 func PersistUnitNameInWorkspace(name string, workspace string) error {
 	file := system.File{
-		Path: path.Join(workspace, "scripts", "unit-name"),
+		Path:               path.Join("scripts", "unit-name"),
 		RawFilePermissions: "0644",
-		Content: name,
+		Content:            name,
 	}
-	return system.WriteFile(&file)
+	_, err := system.WriteFile(&file, workspace)
+	return err
 }