Merge pull request #57879 from bowei/gce-gen

Automatic merge from submit-queue (batch tested with PRs 58025, 57112, 57879, 57571, 58062). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Code generation for GCE compute interface

Use code generation to "write" most of the GCE cloud provider library. This enables the following:

- Consistent interfaces, including handling of the different API versions (GA, alpha, beta)
- Efficient implementation of cross cutting features such as metrics, logging, tracing etc. Adding such features has in the past been a tedious and error prone endeavor. 
- High fidelity mocks for all of the compute API. What this means is that most of our controller logic can be tested as unit tests in a consistent way without creating individual mocks by hand.

```release-note
NONE
```

hack/.golint_failures

@@ -87,6 +87,7 @@ pkg/cloudprovider
 pkg/cloudprovider/providers/aws
 pkg/cloudprovider/providers/fake
 pkg/cloudprovider/providers/gce
+pkg/cloudprovider/providers/gce/cloud
 pkg/cloudprovider/providers/openstack
 pkg/cloudprovider/providers/ovirt
 pkg/cloudprovider/providers/photon

hack/update-cloudprovider-gce.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+# Copyright 2018 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
+
+KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
+source "${KUBE_ROOT}/hack/lib/init.sh"
+GENERATOR="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen/main.go"
+
+GEN_GO="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen.go"
+GEN_TEST_GO="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen_test.go"
+
+kube::golang::setup_env
+
+TMPFILE=$(mktemp verify-cloudprovider-gce-XXXX)
+trap "{ rm -f ${TMPFILE}; }" EXIT
+
+go run "${GENERATOR}" > ${TMPFILE}
+mv "${TMPFILE}" "${GEN_GO}"
+go run "${GENERATOR}" -mode test > ${TMPFILE}
+mv "${TMPFILE}" "${GEN_TEST_GO}"
+
+exit 0

hack/verify-cloudprovider-gce.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+
+# Copyright 2018 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
+
+KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
+source "${KUBE_ROOT}/hack/lib/init.sh"
+GENERATOR="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen/main.go"
+
+GEN_GO="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen.go"
+GEN_TEST_GO="${KUBE_ROOT}/pkg/cloudprovider/providers/gce/cloud/gen_test.go"
+
+kube::golang::setup_env
+
+TMPFILE=$(mktemp verify-cloudprovider-gce-XXXX)
+trap "{ rm -f ${TMPFILE}; }" EXIT
+
+go run "${GENERATOR}" > ${TMPFILE}
+if ! diff "${TMPFILE}" "${GEN_GO}"; then
+  echo "Generated file ${GEN_GO} needs to be updated (run hack/update-cloudprovider-gce.sh)"
+  echo
+  diff -u "${TMPFILE}" "${GEN_GO}" || true
+  exit 1
+fi
+
+go run "${GENERATOR}" -mode test > ${TMPFILE}
+if ! diff "${TMPFILE}" "${GEN_TEST_GO}"; then
+  echo "Generated file ${GEN_TEST_GO} needs to be updated (run hack/update-cloudprovider-gce.sh)"
+  echo
+  diff -u "${TMPFILE}" "${GEN_TEST_GO}" || true
+  exit 1
+fi
+
+exit 0