1. update clientset, deepcopy using code-generator

2. add a dummy file tools.go to force "go mod vendor" to see
code-generator as dependencies
3. add a script to update CRD
4. add a README to document CRD updating steps
run go mod tidy
update README

hack/README.md

@@ -0,0 +1,34 @@
+# Scripts User Guide
+
+This README documents:
+* What update-crd.sh and update-generated-code.sh do
+* When and how to use them
+
+## update-generated-code.sh
+
+This is the script to update clientset/informers/listers and API deepcopy code using [code-generator](https://github.com/kubernetes/code-generator).
+
+Make sure to run this script after making changes to /pkg/apis/volumesnapshot/v1beta1/types.go.
+
+To run this script, simply run: ./hack/update-generated-code.sh from the project root directory.
+
+## update-crd.sh
+
+This is the script to update CRD yaml files under ./config/crd/ based on types.go file.
+
+Make sure to run this script after making changes to /pkg/apis/volumesnapshot/v1beta1/types.go.
+
+Follow these steps to update the CRD:
+
+* Run ./hack/update-crd.sh from root directory, new yaml files should have been created under ./config/crd/
+
+* Replace `api-approved.kubernetes.io` annotation value in all yaml files in the metadata section with your PR.
+For example, `api-approved.kubernetes.io: "https://github.com/kubernetes-csi/external-snapshotter/pull/YOUR-PULL-REQUEST-#"`
+
+* Remove any metadata sections from the yaml file which does not belong to the generated type.
+For example, the following command will add a metadata section for a nested object, remove any newly added metadata sections. TODO(xiangqian): this is to make sure the generated CRD is compatible with apiextensions.k8s.io/v1. Once controller-gen supports generating CRD with apiextensions.k8s.io/v1, switch to use the correct version of controller-gen and remove the last step from this README.
+```bash
+./hack/update-crd.sh; git diff
++        metadata:
++          description: 'Standard object''s metadata. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata'
+```

hack/tools.go

@@ -0,0 +1,22 @@
+// +build tools
+
+/*
+Copyright 2019 The Kubernetes Authors.
+Licensed 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.
+*/
+
+// This package contains code generation utilities
+// This package imports things required by build scripts, to force `go mod` to see them as dependencies
+package tools
+
+import (
+	_ "k8s.io/code-generator"
+)

hack/update-crd.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+# Copyright 2019 The Kubernetes Authors.
+#
+# Licensed 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.
+
+#set -o errexit
+set -o nounset
+set -o pipefail
+
+## find or download controller-gen
+CONTROLLER_GEN=$(which controller-gen)
+
+if [ "$CONTROLLER_GEN" = "" ]
+then
+  TMP_DIR=$(mktemp -d);
+  cd $TMP_DIR;
+  go mod init tmp;
+  go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.2.4;
+  rm -rf $TMP_DIR;
+  CONTROLLER_GEN=$(which controller-gen)
+fi
+
+if [ "$CONTROLLER_GEN" = "" ]
+then
+  echo "ERROR: failed to get controller-gen";
+  exit 1;
+fi
+
+SCRIPT_ROOT=$(unset CDPATH && cd $(dirname "${BASH_SOURCE[0]}")/.. && pwd)
+
+$CONTROLLER_GEN crd:trivialVersions=true,preserveUnknownFields=false paths=${SCRIPT_ROOT}/pkg/apis/volumesnapshot/v1beta1
+
+# To use your own boilerplate text use:
+#   --go-header-file ${SCRIPT_ROOT}/hack/custom-boilerplate.go.txt

hack/update-generated-code.sh

@@ -19,15 +19,14 @@ set -o nounset
 set -o pipefail
 
 SCRIPT_ROOT=$(unset CDPATH && cd $(dirname "${BASH_SOURCE[0]}")/.. && pwd)
-#cd $ROOT
-#SCRIPT_ROOT=$(dirname ${BASH_SOURCE})/..
+
 CODEGEN_PKG=${CODEGEN_PKG:-$(cd ${SCRIPT_ROOT}; ls -d -1 ./vendor/k8s.io/code-generator 2>/dev/null || echo ../code-generator)}
 
 # generate the code with:
 # --output-base    because this script should also be able to run inside the vendor dir of
 #                  k8s.io/kubernetes. The output-base is needed for the generators to output into the vendor dir
 #                  instead of the $GOPATH directly. For normal projects this can be dropped.
-${CODEGEN_PKG}/generate-groups.sh "deepcopy,client,informer,lister" \
+bash ${CODEGEN_PKG}/generate-groups.sh "deepcopy,client,informer,lister" \
   github.com/kubernetes-csi/external-snapshotter/pkg/client github.com/kubernetes-csi/external-snapshotter/pkg/apis \
   volumesnapshot:v1beta1 \
   --go-header-file ${SCRIPT_ROOT}/hack/boilerplate.go.txt