chore: bake the grpc plugin in the hermetic library generation image

.cloudbuild/library_generation/library_generation.Dockerfile

@@ -19,7 +19,9 @@ SHELL [ "/bin/bash", "-c" ]
 
 ARG OWLBOT_CLI_COMMITTISH=ac84fa5c423a0069bbce3d2d869c9730c8fdf550
 ARG PROTOC_VERSION=25.3
+ARG GRPC_VERSION=1.62.2
 ENV HOME=/home
+ENV OS_ARCHITECTURE="linux-x86_64"
 
 # install OS tools
 RUN apt-get update && apt-get install -y \
@@ -32,11 +34,19 @@ COPY library_generation /src
 # install protoc
 WORKDIR /protoc
 RUN source /src/utils/utilities.sh \
-	&& download_protoc "${PROTOC_VERSION}" "linux-x86_64"
+	&& download_protoc "${PROTOC_VERSION}" "${OS_ARCHITECTURE}"
 # we indicate protoc is available in the container via env vars
 ENV DOCKER_PROTOC_LOCATION=/protoc
 ENV DOCKER_PROTOC_VERSION="${PROTOC_VERSION}"
 
+# install grpc
+WORKDIR /grpc
+RUN source /src/utils/utilities.sh \
+	&& download_grpc_plugin "${GRPC_VERSION}" "${OS_ARCHITECTURE}"
+# similar to protoc, we indicate grpc is available in the container via env vars
+ENV DOCKER_GRPC_LOCATION="/grpc/protoc-gen-grpc-java-${GRPC_VERSION}-${OS_ARCHITECTURE}.exe"
+ENV DOCKER_GRPC_VERSION="${GRPC_VERSION}"
+
 # use python 3.11 (the base image has several python versions; here we define the default one)
 RUN rm $(which python3)
 RUN ln -s $(which python3.11) /usr/local/bin/python

library_generation/generate_library.sh

@@ -183,13 +183,15 @@ case "${proto_path}" in
     ;;
 esac
 # download gapic-generator-java, protobuf and grpc plugin.
+# the download_tools function will create the environment variables "protoc_path"
+# and "grpc_path", to be used in the protoc calls below.
 download_tools "${gapic_generator_version}" "${protoc_version}" "${grpc_version}" "${os_architecture}"
 ##################### Section 1 #####################
 # generate grpc-*/
 #####################################################
 if [[ ! "${transport}" == "rest" ]]; then
   # do not need to generate grpc-* if the transport is `rest`.
-  "${protoc_path}"/protoc "--plugin=protoc-gen-rpc-plugin=protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe" \
+  "${protoc_path}"/protoc "--plugin=protoc-gen-rpc-plugin=${grpc_path}" \
   "--rpc-plugin_out=:${temp_destination_path}/java_grpc.jar" \
   ${proto_files} # Do not quote because this variable should not be treated as one long string.
   # unzip java_grpc.jar to grpc-*/src/main/java

library_generation/test/generate_library_unit_tests.sh

@@ -28,10 +28,21 @@ get_grpc_version_failed_with_invalid_generator_version_test() {
   assertEquals 1 $((res))
 }
 
+get_grpc_version_succeed_docker_env_var_test() {
+  local version_with_docker
+  local version_without_docker
+  export DOCKER_GRPC_VERSION="9.9.9"
+  # get_grpc_version should prioritize DOCKER_GRPC_VERSION
+  version_with_docker=$(get_grpc_version "2.24.0")
+  assertEquals "${DOCKER_GRPC_VERSION}" "${version_with_docker}"
+  unset DOCKER_GRPC_VERSION
+}
+
 get_protoc_version_succeed_docker_env_var_test() {
   local version_with_docker
   local version_without_docker
   export DOCKER_PROTOC_VERSION="9.9.9"
+  # get_protoc_version should prioritize DOCKER_PROTOC_VERSION
   version_with_docker=$(get_protoc_version "2.24.0")
   assertEquals "${DOCKER_PROTOC_VERSION}" "${version_with_docker}"
   unset DOCKER_PROTOC_VERSION
@@ -162,13 +173,43 @@ download_tools_succeed_with_baked_protoc() {
 
   local test_ggj_version="2.40.0"
   local test_grpc_version="1.64.0"
+  # we expect download_tools to decide to use DOCKER_PROTOC_LOCATION because
+  # the protoc version we want to download is the same as DOCKER_PROTOC_VERSION.
+  # Note that `protoc_bin_folder` is just the expected formatted value that
+  # download_tools will format using DOCKER_PROTOC_VERSION (via
+  # download_protoc).
   download_tools "${test_ggj_version}" "99.99" "${test_grpc_version}" "linux-x86_64"
   assertEquals "${protoc_bin_folder}" "${protoc_path}"
 
   rm -rdf "${output_folder}"
   unset DOCKER_PROTOC_LOCATION
   unset DOCKER_PROTOC_VERSION
   unset output_folder
+  unset protoc_path
+}
+
+download_tools_succeed_with_baked_grpc() {
+  # This test has the same structure as
+  # download_tools_succeed_with_baked_protoc, but meant for the grpc plugin.
+  local test_dir=$(mktemp -d)
+  pushd "${test_dir}"
+  export DOCKER_GRPC_LOCATION=$(mktemp -d)
+  export DOCKER_GRPC_VERSION="99.99"
+  export output_folder=$(get_output_folder)
+  mkdir "${output_folder}"
+
+  local test_ggj_version="2.40.0"
+  local test_protoc_version="1.64.0"
+  # we expect download_tools to decide to use DOCKER_GRPC_LOCATION because
+  # the protoc version we want to download is the same as DOCKER_GRPC_VERSION
+  download_tools "${test_ggj_version}" "${test_protoc_version}" "99.99" "linux-x86_64"
+  assertEquals "${DOCKER_GRPC_LOCATION}" "${grpc_path}"
+
+  rm -rdf "${output_folder}"
+  unset DOCKER_GRPC_LOCATION
+  unset DOCKER_GRPC_VERSION
+  unset output_folder
+  unset grpc_path
 }
 
 download_grpc_plugin_succeed_with_valid_version_linux_test() {
@@ -293,6 +334,7 @@ test_list=(
   extract_folder_name_test
   get_grpc_version_succeed_with_valid_generator_version_test
   get_grpc_version_failed_with_invalid_generator_version_test
+  get_grpc_version_succeed_docker_env_var_test
   get_protoc_version_succeed_docker_env_var_test
   get_protoc_version_succeed_with_valid_generator_version_test
   get_protoc_version_failed_with_invalid_generator_version_test
@@ -307,6 +349,7 @@ test_list=(
   download_protoc_failed_with_invalid_version_linux_test
   download_protoc_failed_with_invalid_arch_test
   download_tools_succeed_with_baked_protoc
+  download_tools_succeed_with_baked_grpc
   download_grpc_plugin_succeed_with_valid_version_linux_test
   download_grpc_plugin_succeed_with_valid_version_macos_test
   download_grpc_plugin_failed_with_invalid_version_linux_test

library_generation/utils/utilities.sh

@@ -102,9 +102,18 @@ download_gapic_generator_pom_parent() {
   download_generator_artifact "${gapic_generator_version}" "gapic-generator-java-pom-parent-${gapic_generator_version}.pom" "gapic-generator-java-pom-parent"
 }
 
+# This function returns the version of the grpc plugin to generate the libraries. If
+# DOCKER_GRPC_VERSION is set, this will be the version. Otherwise, it will be
+# computed from the gapic-generator-pom-parent artifact at the specified
+# gapic_generator_version.
 get_grpc_version() {
   local gapic_generator_version=$1
   local grpc_version
+  if [[ -n "${DOCKER_GRPC_VERSION}" ]]; then
+    >&2 echo "Using grpc version baked into the container: ${DOCKER_GRPC_VERSION}"
+    echo "${DOCKER_GRPC_VERSION}"
+    return
+  fi
   pushd "${output_folder}" > /dev/null
   # get grpc version from gapic-generator-java-pom-parent/pom.xml
   download_gapic_generator_pom_parent "${gapic_generator_version}"
@@ -113,6 +122,10 @@ get_grpc_version() {
   echo "${grpc_version}"
 }
 
+# This function returns the version of protoc to generate the libraries. If
+# DOCKER_PROTOC_VERSION is set, this will be the version. Otherwise, it will be
+# computed from the gapic-generator-pom-parent artifact at the specified
+# gapic_generator_version.
 get_protoc_version() {
   local gapic_generator_version=$1
   local protoc_version
@@ -129,6 +142,16 @@ get_protoc_version() {
   echo "${protoc_version}"
 }
 
+# Given the versions of the gapic generator, protoc and the protoc-grpc plugin,
+# this function will download each one of the tools and create the environment
+# variables "protoc_path" and "grpc_path" which are expected upstream. Note that
+# if the specified versions of protoc and grpc match DOCKER_PROTOC_VERSION and
+# DOCKER_GRPC_VERSION respectively, this function will instead set "protoc_path"
+# and "grpc_path" to DOCKER_PROTOC_PATH and DOCKER_GRPC_PATH respectively (no
+# download), since the docker image will have downloaded these tools beforehand.
+# For the case of gapic-generator-java, no env var will be exported for the
+# upstream flow, but instead it will be assigned a default filename that will be
+# referenced by the file `library_generation/gapic-generator-java-wrapper`.
 download_tools() {
   local gapic_generator_version=$1
   local protoc_version=$2
@@ -147,7 +170,15 @@ download_tools() {
     export protoc_path=$(download_protoc "${protoc_version}" "${os_architecture}")
   fi
 
-  download_grpc_plugin "${grpc_version}" "${os_architecture}"
+  # similar case with grpc
+  if [[ "${DOCKER_GRPC_VERSION}" == "${grpc_version}" ]]; then
+    # if the specified protoc_version matches the one baked in the docker
+    # container, we just point grpc_path to its location.
+    export grpc_path="${DOCKER_GRPC_LOCATION}"
+  else
+    export grpc_path=$(download_grpc_plugin "${grpc_version}" "${os_architecture}")
+  fi
+
   popd
 }
 
@@ -198,13 +229,15 @@ download_protoc() {
 download_grpc_plugin() {
   local grpc_version=$1
   local os_architecture=$2
-  if [ ! -f "protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe" ]; then
+  grpc_filename="protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe"
+  if [ ! -f "${grpc_filename}" ]; then
     # download protoc-gen-grpc-java plugin from Google maven central mirror.
     download_from \
-    "https://maven-central.storage-download.googleapis.com/maven2/io/grpc/protoc-gen-grpc-java/${grpc_version}/protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe" \
-    "protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe"
-    chmod +x "protoc-gen-grpc-java-${grpc_version}-${os_architecture}.exe"
+    "https://maven-central.storage-download.googleapis.com/maven2/io/grpc/protoc-gen-grpc-java/${grpc_version}/${grpc_filename}" \
+    "${grpc_filename}"
+    chmod +x "${grpc_filename}"
   fi
+  echo "$(pwd)/${grpc_filename}"
 }
 
 download_from() {
@@ -282,7 +315,7 @@ get_proto_path_from_preprocessed_sources() {
   pushd "${sources}" > /dev/null
   local proto_library=$(find . -maxdepth 1 -type d -name 'proto-*' | sed 's/\.\///')
   local found_libraries=$(echo "${proto_library}" | wc -l)
-  if [ -z ${proto_library} ]; then
+  if [[ -z ${proto_library} ]]; then
     echo "no proto libraries found in the supplied sources path"
     exit 1
   elif [ ${found_libraries} -gt 1 ]; then