utils: fork ReadYaml and WriteYaml from juju/utils

provider/maas/util.go

@@ -9,13 +9,13 @@ import (
 	"strings"
 
 	"github.com/juju/errors"
-	"github.com/juju/utils"
-	goyaml "gopkg.in/yaml.v2"
+	goyaml "gopkg.in/yaml.v2" // TODO(dfc) this is horridly wrong, utils.ReadYaml requires yaml.v1
 
 	"github.com/juju/juju/cloudconfig/cloudinit"
 	"github.com/juju/juju/environs/config"
 	"github.com/juju/juju/instance"
 	"github.com/juju/juju/juju/paths"
+	"github.com/juju/juju/utils"
 )
 
 // extractSystemId extracts the 'system_id' part from an InstanceId.

storage/provider/tmpfs.go

@@ -10,10 +10,10 @@ import (
 
 	"github.com/juju/errors"
 	"github.com/juju/names"
-	"github.com/juju/utils"
 
 	"github.com/juju/juju/environs/config"
 	"github.com/juju/juju/storage"
+	"github.com/juju/juju/utils"
 )
 
 const (

utils/yaml.go

@@ -0,0 +1,65 @@
+// Copyright 2012, 2013 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package utils
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/juju/errors"
+	"github.com/juju/utils"
+
+	// juju dependends on the handing of empty elements
+	// provided by yaml.v1. Changing the version of yaml
+	// that this package uses will break juju.
+	"gopkg.in/yaml.v1"
+)
+
+// WriteYaml marshals obj as yaml to a temporary file in the same directory
+// as path, than atomically replaces path with the temporary file.
+func WriteYaml(path string, obj interface{}) error {
+	data, err := yaml.Marshal(obj)
+	if err != nil {
+		return errors.Trace(err)
+	}
+	dir := filepath.Dir(path)
+	f, err := ioutil.TempFile(dir, "juju")
+	if err != nil {
+		return errors.Trace(err)
+	}
+	tmp := f.Name()
+	if _, err := f.Write(data); err != nil {
+		f.Close()      // don't leak file handle
+		os.Remove(tmp) // don't leak half written files on disk
+		return errors.Trace(err)
+	}
+	// Explicitly close the file before moving it. This is needed on Windows
+	// where the OS will not allow us to move a file that still has an open
+	// file handle. Must check the error on close because filesystems can delay
+	// reporting errors until the file is closed.
+	if err := f.Close(); err != nil {
+		os.Remove(tmp) // don't leak half written files on disk
+		return errors.Trace(err)
+	}
+
+	// ioutils.TempFile creates files 0600, but this function has a contract
+	// that files will be world readable, 0644 after replacement.
+	if err := os.Chmod(tmp, 0644); err != nil {
+		os.Remove(tmp) // remove file with incorrect permissions.
+		return errors.Trace(err)
+	}
+
+	return utils.ReplaceFile(tmp, path)
+}
+
+// ReadYaml unmarshals the yaml contained in the file at path into obj. See
+// goyaml.Unmarshal.
+func ReadYaml(path string, obj interface{}) error {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err // cannot wrap here because callers check for NotFound.
+	}
+	return yaml.Unmarshal(data, obj)
+}

worker/meterstatus/state.go

@@ -8,7 +8,8 @@ import (
 	"time"
 
 	"github.com/juju/errors"
-	"github.com/juju/utils"
+
+	"github.com/juju/juju/utils"
 )
 
 // StateFile holds the meter status on disk.

worker/uniter/charm/charm.go

@@ -8,9 +8,10 @@ import (
 	"net/url"
 
 	"github.com/juju/loggo"
-	"github.com/juju/utils"
 	"github.com/juju/utils/set"
 	"gopkg.in/juju/charm.v6-unstable"
+
+	"github.com/juju/juju/utils"
 )
 
 var logger = loggo.GetLogger("juju.worker.uniter.charm")

worker/uniter/charm/manifest_deployer.go

@@ -8,9 +8,11 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/juju/utils"
+	jujuutils "github.com/juju/utils"
 	"github.com/juju/utils/set"
 	"gopkg.in/juju/charm.v6-unstable"
+
+	"github.com/juju/juju/utils"
 )
 
 const (
@@ -147,7 +149,7 @@ func (d *manifestDeployer) finishDeploy() error {
 	logger.Debugf("finishing deploy of charm %q", d.staged.url)
 	oldPath := d.CharmPath(deployingURLPath)
 	newPath := d.CharmPath(charmURLPath)
-	return utils.ReplaceFile(oldPath, newPath)
+	return jujuutils.ReplaceFile(oldPath, newPath)
 }
 
 // ensureBaseFiles checks for an interrupted deploy operation and, if it finds

worker/uniter/operation/state.go

@@ -7,9 +7,9 @@ import (
 	"os"
 
 	"github.com/juju/errors"
-	"github.com/juju/utils"
 	"gopkg.in/juju/charm.v6-unstable"
 
+	"github.com/juju/juju/utils"
 	"github.com/juju/juju/worker/uniter/hook"
 )
 

worker/uniter/relation/state.go

@@ -14,9 +14,9 @@ import (
 	"strings"
 
 	"github.com/juju/errors"
-	"github.com/juju/utils"
 	"gopkg.in/juju/charm.v6-unstable/hooks"
 
+	"github.com/juju/juju/utils"
 	"github.com/juju/juju/worker/uniter/hook"
 )
 

worker/uniter/storage/state.go

@@ -11,9 +11,9 @@ import (
 
 	"github.com/juju/errors"
 	"github.com/juju/names"
-	"github.com/juju/utils"
 	"gopkg.in/juju/charm.v6-unstable/hooks"
 
+	"github.com/juju/juju/utils"
 	"github.com/juju/juju/worker/uniter/hook"
 )
 

worker/uniter/upgrade123.go

@@ -7,9 +7,9 @@ import (
 	"os"
 
 	"github.com/juju/names"
-	"github.com/juju/utils"
 	"gopkg.in/juju/charm.v6-unstable/hooks"
 
+	"github.com/juju/juju/utils"
 	"github.com/juju/juju/worker/uniter/operation"
 )