builder/vmware-esxi: Add configuration options for remote cache path

Add configuration option to explicitly control where Packer uploads
  ISO and floppy files to on ESXi hosts. The `remote_cache_datastore`
  defaults to the `remote_datastore` value. The 'remote_cache_directory'
  defaults to 'packer_cache', similar to the local caching capabilities.

  Addresses issues with [GH-1218] and [GH-1221] where paths for uploaded
  ISO and floppy files are not written to a valid location in the
  datastore.

builder/vmware/iso/builder.go

@@ -47,6 +47,8 @@ type config struct {
 
 	RemoteType           string `mapstructure:"remote_type"`
 	RemoteDatastore      string `mapstructure:"remote_datastore"`
+	RemoteCacheDatastore string `mapstructure:"remote_cache_datastore"`
+	RemoteCacheDirectory string `mapstructure:"remote_cache_directory"`
 	RemoteHost           string `mapstructure:"remote_host"`
 	RemotePort           uint   `mapstructure:"remote_port"`
 	RemoteUser           string `mapstructure:"remote_username"`
@@ -118,6 +120,14 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
 		b.config.RemoteDatastore = "datastore1"
 	}
 
+	if b.config.RemoteCacheDatastore == "" {
+		b.config.RemoteCacheDatastore = b.config.RemoteDatastore
+	}
+
+	if b.config.RemoteCacheDirectory == "" {
+		b.config.RemoteCacheDirectory = "packer_cache"
+	}
+
 	if b.config.RemotePort == 0 {
 		b.config.RemotePort = 22
 	}
@@ -134,6 +144,8 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
 		"remote_type":            &b.config.RemoteType,
 		"remote_host":            &b.config.RemoteHost,
 		"remote_datastore":       &b.config.RemoteDatastore,
+		"remote_cache_datastore": &b.config.RemoteCacheDatastore,
+		"remote_cache_directory": &b.config.RemoteCacheDirectory,
 		"remote_user":            &b.config.RemoteUser,
 		"remote_password":        &b.config.RemotePassword,
 	}

builder/vmware/iso/driver.go

@@ -22,6 +22,8 @@ func NewDriver(config *config) (vmwcommon.Driver, error) {
 			Username:       config.RemoteUser,
 			Password:       config.RemotePassword,
 			Datastore:      config.RemoteDatastore,
+			CacheDatastore: config.RemoteCacheDatastore,
+			CacheDirectory: config.RemoteCacheDirectory,
 		},
 	}
 

builder/vmware/iso/driver_esx5.go

@@ -27,6 +27,8 @@ type ESX5Driver struct {
 	Username  string
 	Password  string
 	Datastore string
+	CacheDatastore string
+	CacheDirectory string
 
 	comm      packer.Communicator
 	outputDir string
@@ -84,13 +86,7 @@ func (d *ESX5Driver) Unregister(vmxPathLocal string) error {
 }
 
 func (d *ESX5Driver) UploadISO(localPath string, checksum string, checksumType string) (string, error) {
-	cacheRoot, _ := filepath.Abs(".")
-	targetFile, err := filepath.Rel(cacheRoot, localPath)
-	if err != nil {
-		return "", err
-	}
-
-	finalPath := d.datastorePath(targetFile)
+	finalPath := d.cachePath(localPath)
 	if err := d.mkdir(filepath.ToSlash(filepath.Dir(finalPath))); err != nil {
 		return "", err
 	}
@@ -297,6 +293,10 @@ func (d *ESX5Driver) datastorePath(path string) string {
 	return filepath.ToSlash(filepath.Join("/vmfs/volumes", d.Datastore, baseDir, filepath.Base(path)))
 }
 
+func (d *ESX5Driver) cachePath(path string) string {
+	return filepath.ToSlash(filepath.Join("/vmfs/volumes", d.CacheDatastore, d.CacheDirectory, filepath.Base(path)))
+}
+
 func (d *ESX5Driver) connect() error {
 	address := fmt.Sprintf("%s:%d", d.Host, d.Port)