Support clients for multiple versions of the same GCP service

[dbolduc]

See https://github.com/googleapis/google-cloud-cpp/blob/main/doc/adr/2022-11-11-multiple-versions-of-GCP-service-in-one-library.md

We need to:

• Update the markdown generator to pick up endpoints from google/cloud/*_options_defaults.cc
• Update the markdown generator to generate samples for the new paths
  • we will need to rename the refs to include version, because they will conflict otherwise
• Add a flag to the generator to generate the following in a library's top-level headers:
  • #include "google/cloud/foo/*.h" headers
  • using ::google::cloud::foo_vN; directives
• Update purely generated libraries' product_path, and enable the flag.
• Update scaffolding to follow the lead of speech/v2 w/r/t service_dirs in bazel and cmake
• Update quickstarts to use versioned clients
• Update samples to use versioned clients (IAM, BQ)

See this branch for what some of the changes should look like. (Next to add them to the generator, and break down the work into logical PRs) https://github.com/googleapis/google-cloud-cpp/compare/main...dbolduc:google-cloud-cpp:speech-reorg-dev?expand=1

[devbww]

See #10278 (vmwareengine/v1) for another example of the proposed layout (without backwards-compatibility headers).

For what it's worth, I used this as a temporary hack for scaffolding generation:

--- a/generator/internal/scaffold_generator.cc
+++ b/generator/internal/scaffold_generator.cc
@@ -133,7 +133,10 @@ void GenerateScaffold(
 
   auto const vars = ScaffoldVars(googleapis_path, service, experimental);
   MakeDirectory(output_path + "/");
-  auto const destination = output_path + "/" + service.product_path() + "/";
+  auto destination = output_path + "/" + service.product_path() + "/";
+  if (service.product_path() == "google/cloud/vmwareengine/v1") {
+    destination = output_path + "/google/cloud/vmwareengine/";
+  }
   MakeDirectory(destination);
   MakeDirectory(destination + "doc/");
   MakeDirectory(destination + "quickstart/");

[dbolduc]

This is the script I used to generate #10857

#!/bin/bash
#
# Usage: ./relocate.sh apigateway kms osconfig
#
# If anything goes wrong, it will likely be in the "update builds" step.
#
# Verify the result with:
# ```
# ci/cloudbuild/build.sh -t cmake-install-pr
# bazel build //google/cloud/...
# ```

libraries=("$@")

function edit_config() {
  library=$1
  service_dirs=("\"\"") # Remember these. They are needed in Step 5.
  vals=($(grep "service_proto_path: .*${library}.*v[0-9]" generator/generator_config.textproto -no | sed "s;service_proto_path:.*${library}/;;"))
  # Assume that `product_path` immediately follows `service_proto_path`.
  line_offset=1
  for v in "${vals[@]}"; do
    line=${v%:*}
    subdir=${v#*:}
    service_dirs+=("\"${subdir}/\"")
    sed -i "$(($line+$line_offset))s;${library};${library}/${subdir};" generator/generator_config.textproto
    # We need to increment the index for each `forwarding_product_path` line we add.
    ((line_offset+=1))
    sed -i "$(($line+$line_offset))i \ \ forwarding_product_path: \"google/cloud/${library}\"" generator/generator_config.textproto
  done
  # Store in a file because dbolduc does not know how maps work.
  printf "%s\n" "${service_dirs[@]}" | sort | uniq > dirs_${library}.tmp
}

function update_bazel() {
  mapfile -t service_dirs < dirs_${library}.tmp
  {
    sed -n '1,18p' google/cloud/${library}/BUILD.bazel
    echo "service_dirs = ["
    for d in "${service_dirs[@]}"; do
      echo "    ${d}",
    done
    sed -n '22,39p' google/cloud/accessapproval/BUILD.bazel
    sed -n '39,$p' google/cloud/${library}/BUILD.bazel
    sed -n '62,$p' google/cloud/accessapproval/BUILD.bazel | sed "s/accessapproval/${library}/"
  } > dern.tmp && mv dern.tmp google/cloud/${library}/BUILD.bazel
}

function update_cmake() {
  mapfile -t service_dirs < dirs_${library}.tmp
  {
    sed '/set(DOXYGEN_PROJECT_NUMBER/q' google/cloud/${library}/CMakeLists.txt
    sed -n '21,37p' google/cloud/accessapproval/CMakeLists.txt | sed "s/accessapproval/${library}/" | sed "s;\"\" \"v1/\";${service_dirs[*]};"
    sed -n '/include(GoogleCloudCppDoxygen)/,$p' google/cloud/${library}/CMakeLists.txt | sed 's;"\*.h" "\*.cc" "internal/\*.h" "internal/\*.cc";${source_globs};' | sed 's;"mocks/\*.h";${mocks_globs};'
    # Use tpu because accessapproval breaks the comment onto two lines.
    sed -n '182,$p' google/cloud/tpu/CMakeLists.txt | sed "s;tpu;${library};g"
  } > dern.tmp && mv dern.tmp google/cloud/${library}/CMakeLists.txt
}

# Checkout new branch
git checkout -b relocate-libraries

# Edit generator configuration
for library in "${libraries[@]}"; do
  edit_config $library
done
git commit -m "refactor: versioned clients" generator/generator_config.textproto

# Regenerate libraries
ci/cloudbuild/build.sh -t generate-libraries-pr
git add google/
ci/cloudbuild/build.sh -t checkers-pr
git commit -m "generated changes" ci/ google/

# Remove stale code
for library in "${libraries[@]}"; do
  rm google/cloud/$library/*.cc
  rm -rf google/cloud/$library/internal
  rm -rf google/cloud/$library/samples
done
git add google/
ci/cloudbuild/build.sh -t checkers-pr
git commit -m "remove stale code; regenerate docs" google/

# Update build files
for library in "${libraries[@]}"; do
  update_bazel $library
  update_cmake $library
  rm dirs_${library}.tmp
done
ci/cloudbuild/build.sh -t checkers-pr
git commit -m "update build files" google/

# Update ABI dumps
ci/cloudbuild/build.sh -t check-api-pr
for library in "${libraries[@]}"; do
  git add ci/abi-dumps/google_cloud_cpp_$library.expected.abi.dump.gz
done
git commit -m "update ABI dumps"

[dbolduc]

For posterity, here is the final script I used:

#!/bin/bash
#
# Usage: ./relocate.sh apigateway kms osconfig
#
# If anything goes wrong, it will likely be in the "update builds" step.
#
# Verify the result with:
# ```
# ci/cloudbuild/build.sh -t cmake-install-pr
# bazel build //google/cloud/...
# ```

set -euo pipefail

libraries=("$@")

function edit_config() {
  library=$1
  gc_dir=$library
  if [[ $gc_dir == "dialogflow_cx" ]]; then gc_dir="dialogflow/cx"; fi
  if [[ $gc_dir == "gameservices" ]]; then gc_dir="gaming"; fi
  if [[ $gc_dir == "datamigration" ]]; then gc_dir="clouddms"; fi
  if [[ $gc_dir == "profiler" ]]; then gc_dir="cloudprofiler"; fi
  if [[ $gc_dir == "trace" ]]; then gc_dir="cloudtrace"; fi
  service_dirs=("\"\"") # Remember these. They are needed in Step 5.
  vals=($(grep "service_proto_path: .*/${gc_dir}/.*v[0-9]" generator/generator_config.textproto -no | sed "s;service_proto_path:.*${gc_dir}/;;"))
  inserts=0
  for v in "${vals[@]}"; do
    og_line=${v%:*}
    subdir=${v#*:}
    service_dirs+=("\"${subdir}/\"")
    # Find the index of the product_path. It is not always on the line after the
    # `service_proto_path`, if there are `additional_proto_files` defined.
    ((line=$og_line+$inserts+1))
    while [ $(sed -n "${line}p" generator/generator_config.textproto | grep product_path | wc -w) -eq 0 ]; do
      ((line+=1))
    done
    sed -i "${line}s;${library};${library}/${subdir};" generator/generator_config.textproto
    # We also need to increment the index for each `forwarding_product_path` line we add.
    ((inserts+=1))
    ((line+=1))
    sed -i "${line}i \ \ forwarding_product_path: \"google/cloud/${library}\"" generator/generator_config.textproto
  done
  # Store in a file because dbolduc does not know how maps work.
  printf "%s\n" "${service_dirs[@]}" | sort | uniq > dirs_${library}.tmp
}

function check_typos() {
  library=$1
  if [ $(grep "google/cloud/$library/" .typos.toml | wc -w) -gt 0 ]; then
    nvim .typos.toml
    git commit -m "manually edit typos" .typos.toml
  fi
}

function update_bazel() {
  mapfile -t service_dirs < dirs_${library}.tmp
  {
    sed -n '1,18p' google/cloud/${library}/BUILD.bazel
    echo "service_dirs = ["
    for d in "${service_dirs[@]}"; do
      echo "    ${d}",
    done
    sed -n '22,39p' google/cloud/accessapproval/BUILD.bazel
    sed -n '39,$p' google/cloud/${library}/BUILD.bazel
    sed -n '62,$p' google/cloud/accessapproval/BUILD.bazel | sed "s/accessapproval/${library}/"
  } > dern.tmp && mv dern.tmp google/cloud/${library}/BUILD.bazel
}

function update_cmake() {
  mapfile -t service_dirs < dirs_${library}.tmp
  {
    sed '/set(DOXYGEN_PROJECT_NUMBER/q' google/cloud/${library}/CMakeLists.txt
    sed -n '21,37p' google/cloud/accessapproval/CMakeLists.txt | sed "s/accessapproval/${library}/" | sed "s;\"\" \"v1/\";${service_dirs[*]};"
    sed -n '/include(GoogleCloudCppDoxygen)/,$p' google/cloud/${library}/CMakeLists.txt | sed 's;"\*.h" "\*.cc" "internal/\*.h" "internal/\*.cc";${source_globs};' | sed 's;"mocks/\*.h";${mocks_globs};'
    # Use tpu because accessapproval breaks the comment onto two lines.
    sed -n '182,$p' google/cloud/tpu/CMakeLists.txt | sed "s;tpu;${library};g"
  } > dern.tmp && mv dern.tmp google/cloud/${library}/CMakeLists.txt
}

# Checkout new branch
git checkout main
git pull --ff-only upstream main
git checkout -b relocate-${libraries[0]}

# Edit generator configuration
for library in "${libraries[@]}"; do
  edit_config $library
done
git commit -m "refactor(${libraries[0]}): versioned clients" generator/generator_config.textproto

for library in "${libraries[@]}"; do
  check_typos $library
done

# Regenerate libraries
ci/cloudbuild/build.sh -t generate-libraries-pr || true
git add google/
ci/cloudbuild/build.sh -t checkers-pr || true
git commit -m "generated changes" ci/ google/

# Remove stale code
for library in "${libraries[@]}"; do
  rm google/cloud/$library/*.cc
  rm -rf google/cloud/$library/internal
  # Libraries with handwritten samples need finer tuning
  rm -rf google/cloud/$library/samples
done
git add google/
ci/cloudbuild/build.sh -t checkers-pr || true
git commit -m "remove stale code; regenerate docs" google/

# Update build files
for library in "${libraries[@]}"; do
  update_bazel $library
  update_cmake $library
  # Cleanup temporary files
  rm dirs_${library}.tmp
done
ci/cloudbuild/build.sh -t checkers-pr || true
git commit -m "update build files" google/

# Update ABI dumps
mapfile -t libs < <(for library in ${libraries[@]}; do echo google_cloud_cpp_$library; done)
sed -i "131s/.*/libraries=(${libs[*]})/" ci/cloudbuild/builds/check-api.sh
ci/cloudbuild/build.sh -t check-api-pr || true
git add ci/abi-dumps
git restore ci/cloudbuild/builds/check-api.sh
git commit -m "update ABI dumps"

# Test and move on, lol.
for library in "${libraries[@]}"; do
  bazel build //google/cloud/$library/...
done
git push -u origin relocate-${libraries[0]}

[dbolduc]

Current State

All libraries have versioned clients except for the following exceptions.

Heavily handwritten:

• bigtable
• pubsub
• pubsublite
• spanner
• storage

Sorta versioned already:

• dialogflow_cx
• dialogflow_es

@coryan suggests that we might want a single dialogflow library, which dialogflow_cx and dialogflow_es depend on for backwards compatibility. If we do this, we should track it in a separate issue.

Obnoxious googleapis directory structure

• composer

google-cloud-cpp/generator/generator_config.textproto

Lines 402 to 404 in a5572b1

	service_proto_path: "google/cloud/orchestration/airflow/service/v1/environments.proto"
	additional_proto_files: ["google/cloud/orchestration/airflow/service/v1/operations.proto"]
	product_path: "google/cloud/composer"

Maybe we should just make it composer/v1