Make protobindings gen a bit safer

hack/lib/protoc.sh

@@ -64,7 +64,7 @@ function kube::protoc::protoc() {
     # isn't).  The inputs to this function do not all have a common root, so
     # this works best for all inputs.
     PATH="${gogopath}:${PATH}" protoc \
-      --proto_path="${package}" \
+      --proto_path="$(pwd -P)" \
       --proto_path="${KUBE_ROOT}/vendor" \
       --gogo_out=paths=source_relative,plugins=grpc:. \
       api.proto

hack/update-generated-proto-bindings-dockerized.sh

@@ -23,8 +23,9 @@ set -o pipefail
 KUBE_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../" && pwd -P)"
 
 source "${KUBE_ROOT}/hack/lib/protoc.sh"
+source "${KUBE_ROOT}/hack/lib/util.sh"
 
-if [ "$#" = 0 ]; then
+if [ "$#" == 0 ]; then
     echo "usage: $0 <api_dir>..."
     exit 1
 fi
@@ -32,9 +33,17 @@ fi
 for api; do
     # This can't use `git ls-files` because it runs in a container without the
     # .git dir synced.
-    find "${api}" -type f -name "api.proto" \
-        | while read -r F; do
-            D="$(dirname "${F}")"
-            kube::protoc::generate_proto "${KUBE_ROOT}/${D}"
-        done
+    protos=()
+    kube::util::read-array protos < <( \
+        find "${api}" -type f -name "api.proto")
+
+    if [ "${#protos[@]}" == 0 ]; then
+        echo "ERROR: no 'api.proto' files under '${api}'"
+        exit 1
+    fi
+
+    for file in "${protos[@]}"; do
+        dir="$(dirname "${file}")"
+        kube::protoc::generate_proto "${dir}"
+    done
 done