Add experimental docker stack commands

Signed-off-by: Daniel Nephin <dnephin@docker.com>

api/client/bundlefile/bundlefile.go

@@ -0,0 +1,62 @@
+// +build experimental
+
+package bundlefile
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+)
+
+// Bundlefile stores the contents of a bundlefile
+type Bundlefile struct {
+	Version  string
+	Services map[string]Service
+}
+
+// Service is a service from a bundlefile
+type Service struct {
+	Image      string
+	Command    []string          `json:",omitempty"`
+	Args       []string          `json:",omitempty"`
+	Env        []string          `json:",omitempty"`
+	Labels     map[string]string `json:",omitempty"`
+	Ports      []Port            `json:",omitempty"`
+	WorkingDir *string           `json:",omitempty"`
+	User       *string           `json:",omitempty"`
+	Networks   []string          `json:",omitempty"`
+}
+
+// Port is a port as defined in a bundlefile
+type Port struct {
+	Protocol string
+	Port     uint32
+}
+
+// LoadFile loads a bundlefile from a path to the file
+func LoadFile(path string) (*Bundlefile, error) {
+	reader, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	bundlefile := &Bundlefile{}
+
+	if err := json.NewDecoder(reader).Decode(bundlefile); err != nil {
+		return nil, err
+	}
+
+	return bundlefile, err
+}
+
+// Print writes the contents of the bundlefile to the output writer
+// as human readable json
+func Print(out io.Writer, bundle *Bundlefile) error {
+	bytes, err := json.MarshalIndent(*bundle, "", "    ")
+	if err != nil {
+		return err
+	}
+
+	_, err = out.Write(bytes)
+	return err
+}