chore: add check to create list of non-compilable libraries (#20880)

* add verify compilation script

* add github workflow

* fix syntax

* use supported java version

* fix script path

* add checkout step

* use working dir

* fix wrong export

* add flags in find exec

* fix parallel processing

* use moreutils parallel

* fix utils install

* test paths to parallel

* specify moreutils parallel

* test location of parallel

* handle renamed parallel

* fix comment

* target only 2.0.0 libraries

* print list of target liibaries

* remove unnecessary export statement

Author: diegomarquezp

.github/workflows/verify.yaml

@@ -0,0 +1,24 @@
+on:
+  schedule:
+    # Runs at 04:00 am
+    - cron: '0 4 * * *'
+  workflow_dispatch:
+# Generates a list of libraries that cannot be
+# compiled (printed to the action stdout)
+name: Verify libraries compilation
+jobs:
+  verify:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/setup-java@v3
+        with:
+          distribution: temurin
+          java-version: 8
+      - uses: actions/checkout@v2
+        with:
+          path: google-api-java-client-services
+      # we install the moreutils `parallel` command
+      - run: sudo apt-get install moreutils
+      - working-directory: google-api-java-client-services
+        run: bash .github/workflows/verify_compilation.sh
+

.github/workflows/verify_compilation.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+# This script loops over the generated clients and uses `mvn compile` to
+# create a list of clients that cannot be compiled. The resulting list is
+# printed to stdout
+set -exo
+repo_root=$(git rev-parse --show-toplevel)
+export failed_libs="${repo_root}/failed_libs"
+
+process_client() {
+  pom_dir=$1
+  pushd "${pom_dir}"
+  lib_name=$(pwd | sed 's/.*\(google-api-services-.*\)/\1/')
+  mvn compile || echo "${lib_name}" >> "${failed_libs}"
+  popd #pom_dir
+}
+
+print_failed_libraries() {
+  if [[ $(cat "${failed_libs}" | wc -l) -ne 0 ]]; then
+    echo "The following libraries had compilation errors:"
+    cat "${failed_libs}"
+    exit 1
+  else
+    echo "All libraries were compiled successfully!"
+  fi
+}
+
+# export process_client so it can be accessed by the inner shell launched by the
+# find command
+export -f process_client
+# for convenience in local setups, we remove the failed libraries list
+# beforehand
+if [[ -f "${failed_libs}" ]];then
+  rm "${failed_libs}"
+fi
+pushd "${repo_root}"
+
+# some distros rename parallel to parallel.moreutils
+parallel_bin="parallel.moreutils"
+which parallel.moreutils || parallel_bin="parallel"
+
+# runs mvn compile in parallel (max 50 jobs)
+targets=$(find "clients" -mindepth 3 -name '*2.0.0*' -printf '%p ')
+echo "Attempting compilation on the following libraries:"
+set +x
+echo "${targets}" | sed 's/ /\n/g' | sort
+set -x
+${parallel_bin} -j50 -i bash -xe -c 'process_client "{}"' -- ${targets}
+
+print_failed_libraries
+
+
+popd #repo_root