Add support for plugin build for darwin amd64

incubator/hnc/cloudbuild.yaml

@@ -30,7 +30,8 @@ steps:
     kustomize build . -o ./hnc-manager.yaml
 
     # Build plugin
-    go build -o kubectl-hns ../cmd/kubectl/main.go
+    GOOS=linux GOARCH=amd64 go build -o kubectl-hns_linux_amd64 ../cmd/kubectl/main.go
+    GOOS=darwin GOARCH=amd64 go build -o kubectl-hns_darwin_amd64 ../cmd/kubectl/main.go
 # Upload manifest
 - name: gcr.io/cloud-builders/curl
   args:
@@ -43,18 +44,30 @@ steps:
   - '-u'
   - '$_HNC_USER:$_HNC_PERSONAL_ACCESS_TOKEN'
   - 'https://uploads.github.com/repos/kubernetes-sigs/multi-tenancy/releases/$_HNC_RELEASE_ID/assets?name=hnc-manager.yaml'
-# Upload plugin
+# Upload plugin (Linux)
 - name: gcr.io/cloud-builders/curl
   args:
   - '-X'
   - 'POST'
   - '-H'
   - 'Content-Type: application/x-application'
   - '--data-binary'
-  - '@multi-tenancy/incubator/hnc/out/kubectl-hns'
+  - '@multi-tenancy/incubator/hnc/out/kubectl-hns_linux_amd64'
   - '-u'
   - '$_HNC_USER:$_HNC_PERSONAL_ACCESS_TOKEN'
-  - 'https://uploads.github.com/repos/kubernetes-sigs/multi-tenancy/releases/$_HNC_RELEASE_ID/assets?name=kubectl-hns'
+  - 'https://uploads.github.com/repos/kubernetes-sigs/multi-tenancy/releases/$_HNC_RELEASE_ID/assets?name=kubectl-hns_linux_amd64'
+# Upload plugin (Darwin)
+- name: gcr.io/cloud-builders/curl
+  args:
+  - '-X'
+  - 'POST'
+  - '-H'
+  - 'Content-Type: application/x-application'
+  - '--data-binary'
+  - '@multi-tenancy/incubator/hnc/out/kubectl-hns_darwin_amd64'
+  - '-u'
+  - '$_HNC_USER:$_HNC_PERSONAL_ACCESS_TOKEN'
+  - 'https://uploads.github.com/repos/kubernetes-sigs/multi-tenancy/releases/$_HNC_RELEASE_ID/assets?name=kubectl-hns_darwin_amd64'
 # Build Docker image
 - name: gcr.io/cloud-builders/docker
   args: ['build', '-t', 'gcr.io/$PROJECT_ID/$_HNC_IMG_NAME:$_HNC_IMG_TAG', 'multi-tenancy/incubator/hnc']