Add s390x support for puller and loader binaries (#1645)

Author: srajmane

container/go/cloudbuild.yaml

@@ -93,6 +93,38 @@ steps:
       - "gs://rules_docker/$COMMIT_SHA/loader-linux-arm64"
     id: "push-loader-linux-arm64"
     waitFor: ["build-linux-arm64"]
+    
+# Step: build the puller and pusher release binary for Linux s390x
+  - name: "l.gcr.io/google/bazel"
+    args:
+      - "build"
+      - "--platforms=@io_bazel_rules_go//go/toolchain:linux_s390x"
+      - "//container/go/cmd/puller:puller"
+      - "//container/go/cmd/loader:loader"
+    id: "build-linux-s390x"
+    waitFor: ["push-puller-linux-arm64", "push-loader-linux-arm64"]
+
+# Step: push the puller release binary for Linux s390x
+  - name: "gcr.io/cloud-builders/gsutil"
+    args:
+      - "cp"
+      - "-a"
+      - "public-read"
+      - "bazel-bin/container/go/cmd/puller/puller_/puller"
+      - "gs://rules_docker/$COMMIT_SHA/puller-linux-s390x"
+    id: "push-puller-linux-s390x"
+    waitFor: ["build-linux-s390x"]
+
+# Step: push the loader release binary for Linux s390x
+  - name: "gcr.io/cloud-builders/gsutil"
+    args:
+      - "cp"
+      - "-a"
+      - "public-read"
+      - "bazel-bin/container/go/cmd/loader/loader_/loader"
+      - "gs://rules_docker/$COMMIT_SHA/loader-linux-s390x"
+    id: "push-loader-linux-s390x"
+    waitFor: ["build-linux-s390x"]
 
 # Step: build the puller and loader release binaries for Darwin AMD64
   - name: "l.gcr.io/google/bazel"
@@ -102,7 +134,7 @@ steps:
       - "//container/go/cmd/puller:puller"
       - "//container/go/cmd/loader:loader"
     id: "build-darwin-amd64"
-    waitFor: ["push-puller-linux-arm64", "push-loader-linux-arm64"]
+    waitFor: ["push-puller-linux-s390x", "push-loader-linux-s390x"]
 
 # Step: push the puller release binary for Darwin AMD64
   - name: "gcr.io/cloud-builders/gsutil"