http/logical: Add http GET parameters to the data map (#4012)

* Add get parameters to the data object

* Add test for get params

http/logical.go

@@ -75,6 +75,30 @@ func buildLogicalRequest(core *vault.Core, w http.ResponseWriter, r *http.Reques
 		}
 	}
 
+	// If we are a read operation, try and parse any parameters
+	if op == logical.ReadOperation {
+		getData := map[string]interface{}{}
+
+		for k, v := range r.URL.Query() {
+			// Skip the help key as this is a reserved parameter
+			if k == "help" {
+				continue
+			}
+
+			switch {
+			case len(v) == 0:
+			case len(v) == 1:
+				getData[k] = v[0]
+			default:
+				getData[k] = v
+			}
+		}
+
+		if len(getData) > 0 {
+			data = getData
+		}
+	}
+
 	var err error
 	request_id, err := uuid.GenerateUUID()
 	if err != nil {