rc: Add operations/uploadfile to upload a file through rc using encoding multipart/form-data

fs/rc/params.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math"
+	"net/http"
 	"strconv"
 	"time"
 
@@ -90,6 +91,23 @@ func (p Params) Get(key string) (interface{}, error) {
 	return value, nil
 }
 
+// GetHTTPRequest gets a http.Request parameter associated with the request with the key "HttpRequest"
+//
+// If the parameter isn't found then error will be of type
+// ErrParamNotFound and the returned value will be nil.
+func (p Params) GetHTTPRequest() (*http.Request, error) {
+	key := "_request"
+	value, err := p.Get(key)
+	if err != nil {
+		return nil, err
+	}
+	request, ok := value.(*http.Request)
+	if !ok {
+		return nil, ErrParamInvalid{errors.Errorf("expecting http.request value for key %q (was %T)", key, value)}
+	}
+	return request, nil
+}
+
 // GetString gets a string parameter from the input
 //
 // If the parameter isn't found then error will be of type