Force parameters to be required to maintain backward compatability

Makefile

@@ -14,7 +14,7 @@ SHELL = /usr/bin/env bash -o pipefail
 all: code mocks test
 
 code:
-	go run generate/generate.go generate/layout.go --api=generate/listApis.json
+	go run generate/generate.go generate/layout.go generate/requiredParams.go --api=generate/listApis.json
 
 FILES=$(shell for file in `pwd`/cloudstack/*Service.go ;do basename $$file .go ; done)
 mocks:

generate/generate.go

@@ -1197,8 +1197,14 @@ func (s *service) generateInterfaceType() {
 		p("New%s(", tn)
 		for _, ap := range api.Params {
 			if ap.Required {
-				// rp = append(rp, ap)
 				p("%s %s, ", s.parseParamName(ap.Name), mapType(api.Name, ap.Name, ap.Type))
+			} else if params, ok := requiredParams[api.Name]; ok {
+				for _, param := range params {
+					if param == ap.Name {
+						p("%s %s, ", s.parseParamName(ap.Name), mapType(api.Name, ap.Name, ap.Type))
+						break
+					}
+				}
 			}
 		}
 		pn(") *%s", tn)
@@ -1423,6 +1429,14 @@ func (s *service) generateNewParamTypeFunc(a *API) {
 		if ap.Required {
 			rp = append(rp, ap)
 			p("%s %s, ", s.parseParamName(ap.Name), mapType(a.Name, ap.Name, ap.Type))
+		} else if params, ok := requiredParams[a.Name]; ok {
+			for _, param := range params {
+				if param == ap.Name {
+					rp = append(rp, ap)
+					p("%s %s, ", s.parseParamName(ap.Name), mapType(a.Name, ap.Name, ap.Type))
+					break
+				}
+			}
 		}
 	}
 	pn(") *%s {", tn)

generate/requiredParams.go

@@ -0,0 +1,54 @@
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+//
+
+package main
+
+// This map contains the API commands and the parameters which needs to be made
+// made required to ensure backward compatibility with the older versions of
+// the CloudStack API.
+
+var requiredParams = map[string][]string{
+	"createNetworkOffering": {
+		"displaytext",
+	},
+	"createDiskOffering": {
+		"displaytext",
+	},
+	"createServiceOffering": {
+		"displaytext",
+	},
+	"createVPCOffering": {
+		"displaytext",
+	},
+	"registerIso": {
+		"displaytext",
+	},
+	"createProject": {
+		"displaytext",
+	},
+	"createTemplate": {
+		"displaytext",
+	},
+	"registerTemplate": {
+		"displaytext",
+	},
+	"createVPC": {
+		"displaytext",
+	},
+}