chore(backend): include protoc-gen-go-grpc as tools dependency and ad…

…d go mod tidy check in CI (#5112)

* chore(backend): include protoc-gen-go-grpc as tools dependency

* add go mod tidy check in presubmit

* add comment

* fix2

* add better error message

* fix

go.mod

@@ -41,7 +41,7 @@ require (
 	google.golang.org/api v0.20.0
 	google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013
 	google.golang.org/grpc v1.34.0
-	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.0.1 // indirect
+	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.0.1
 	google.golang.org/protobuf v1.25.0
 	gopkg.in/yaml.v2 v2.3.0
 	k8s.io/api v0.17.9

test/presubmit-backend-test.sh

@@ -14,14 +14,23 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# Fail the entire script when any command fails.
+set -ex
+
 # The current directory is /home/prow/go/src/github.com/kubeflow/pipelines
+# TODO(Bobgy): we should use golang image instead, to skip installing go manually.
 # 1. install go in /home/prow/go1.13.3
 cd /home/prow
 mkdir go1.13.3
 cd go1.13.3
 wget --quiet https://dl.google.com/go/go1.13.3.linux-amd64.tar.gz
 tar -xf go1.13.3.linux-amd64.tar.gz
-# 2. run test in project directory
+GO_CMD=/home/prow/go1.13.3/go/bin/go
 cd /home/prow/go/src/github.com/kubeflow/pipelines
-/home/prow/go1.13.3/go/bin/go mod vendor
-/home/prow/go1.13.3/go/bin/go test -v -cover ./backend/...
+# 2. Check go modules are tidy
+# Reference: https://github.com/golang/go/issues/27005#issuecomment-564892876
+${GO_CMD} mod download
+${GO_CMD} mod tidy
+git diff --exit-code -- go.mod go.sum || (echo "go modules are not tidy, run 'go mod tidy'." && exit 1)
+# 3. run test in project directory
+${GO_CMD} test -v -cover ./backend/...

tools/tools.go

@@ -7,5 +7,6 @@ package tools
 
 import (
 	_ "github.com/google/addlicense"
+	_ "google.golang.org/grpc/cmd/protoc-gen-go-grpc"
 	_ "k8s.io/code-generator"
 )