Create all directories before creating a new file (#511)

Summary:
From the golang 1.23 os/file.go
```
// Flags to OpenFile wrapping those of the underlying system. Not all
// flags may be implemented on a given system.
const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only.
	O_RDWR   int = syscall.O_RDWR   // open the file read-write.
	// The remaining values may be or'ed in to control behavior.
	O_APPEND int = syscall.O_APPEND // append data to the file when writing.
	O_CREATE int = syscall.O_CREAT  // create a new file if none exists.
	O_EXCL   int = syscall.O_EXCL   // used with O_CREATE, file must not exist.
	O_SYNC   int = syscall.O_SYNC   // open for synchronous I/O.
	O_TRUNC  int = syscall.O_TRUNC  // truncate regular writable file when opened.
)
```

Which makes me think that we might want to call MkdirAll function before creating a file

Pull Request resolved: #511

Resolves #506

Differential Revision: D61658174

fbshipit-source-id: b0352f44335f19773854170df787292676cf5a8e

pkg/blocks/createfile.go

@@ -22,6 +22,7 @@ package blocks
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/facebookincubator/ttpforge/pkg/fileutils"
 	"github.com/facebookincubator/ttpforge/pkg/logging"
@@ -94,6 +95,17 @@ func (s *CreateFileStep) Execute(_ TTPExecutionContext) (*ActResult, error) {
 		mode = 0666
 	}
 
+	dir := filepath.Dir(pathToCreate)
+	exists, err = afero.Exists(fsys, dir)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		if err = fsys.MkdirAll(dir, os.ModePerm); err != nil {
+			return nil, err
+		}
+	}
+
 	// actually write the file
 	f, err := fsys.OpenFile(pathToCreate, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(mode))
 	if err != nil {