Remove call to template.Option when building with 1.4.

Windows still relies on 1.4.2 to build Docker.

Signed-off-by: David Calavera <david.calavera@gmail.com>

api/client/inspect/inspector.go

@@ -39,33 +39,13 @@ func (i *TemplateInspector) Inspect(typedElement interface{}, rawElement []byte)
 		if rawElement == nil {
 			return fmt.Errorf("Template parsing error: %v", err)
 		}
-		return i.tryRawInspectFallback(rawElement)
+		return i.tryRawInspectFallback(rawElement, err)
 	}
 	i.buffer.Write(buffer.Bytes())
 	i.buffer.WriteByte('\n')
 	return nil
 }
 
-func (i *TemplateInspector) tryRawInspectFallback(rawElement []byte) error {
-	var raw interface{}
-	buffer := new(bytes.Buffer)
-	rdr := bytes.NewReader(rawElement)
-	dec := json.NewDecoder(rdr)
-
-	if rawErr := dec.Decode(&raw); rawErr != nil {
-		return fmt.Errorf("unable to read inspect data: %v", rawErr)
-	}
-
-	tmplMissingKey := i.tmpl.Option("missingkey=error")
-	if rawErr := tmplMissingKey.Execute(buffer, raw); rawErr != nil {
-		return fmt.Errorf("Template parsing error: %v", rawErr)
-	}
-
-	i.buffer.Write(buffer.Bytes())
-	i.buffer.WriteByte('\n')
-	return nil
-}
-
 // Flush write the result of inspecting all elements into the output stream.
 func (i *TemplateInspector) Flush() error {
 	_, err := io.Copy(i.outputStream, i.buffer)

api/client/inspect/inspector_go14.go

@@ -0,0 +1,40 @@
+// +build !go1.5
+
+package inspect
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+// tryeRawInspectFallback executes the inspect template with a raw interface.
+// This allows docker cli to parse inspect structs injected with Swarm fields.
+// Unfortunately, go 1.4 doesn't fail executing invalid templates when the input is an interface.
+// It doesn't allow to modify this behavior either, sending <no value> messages to the output.
+// We assume that the template is invalid when there is a <no value>, if the template was valid
+// we'd get <nil> or "" values. In that case we fail with the original error raised executing the
+// template with the typed input.
+func (i *TemplateInspector) tryRawInspectFallback(rawElement []byte, originalErr error) error {
+	var raw interface{}
+	buffer := new(bytes.Buffer)
+	rdr := bytes.NewReader(rawElement)
+	dec := json.NewDecoder(rdr)
+
+	if rawErr := dec.Decode(&raw); rawErr != nil {
+		return fmt.Errorf("unable to read inspect data: %v", rawErr)
+	}
+
+	if rawErr := i.tmpl.Execute(buffer, raw); rawErr != nil {
+		return fmt.Errorf("Template parsing error: %v", rawErr)
+	}
+
+	if strings.Contains(buffer.String(), "<no value>") {
+		return fmt.Errorf("Template parsing error: %v", originalErr)
+	}
+
+	i.buffer.Write(buffer.Bytes())
+	i.buffer.WriteByte('\n')
+	return nil
+}

api/client/inspect/inspector_go15.go

@@ -0,0 +1,29 @@
+// +build go1.5
+
+package inspect
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+)
+
+func (i *TemplateInspector) tryRawInspectFallback(rawElement []byte, _ error) error {
+	var raw interface{}
+	buffer := new(bytes.Buffer)
+	rdr := bytes.NewReader(rawElement)
+	dec := json.NewDecoder(rdr)
+
+	if rawErr := dec.Decode(&raw); rawErr != nil {
+		return fmt.Errorf("unable to read inspect data: %v", rawErr)
+	}
+
+	tmplMissingKey := i.tmpl.Option("missingkey=error")
+	if rawErr := tmplMissingKey.Execute(buffer, raw); rawErr != nil {
+		return fmt.Errorf("Template parsing error: %v", rawErr)
+	}
+
+	i.buffer.Write(buffer.Bytes())
+	i.buffer.WriteByte('\n')
+	return nil
+}