storage_client_initialization_samples.cc

// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "google/cloud/storage/client.h"
#include "google/cloud/storage/examples/storage_examples_common.h"
#include "google/cloud/storage/parallel_upload.h"
#include "google/cloud/storage/well_known_parameters.h"
#include "google/cloud/credentials.h"
#include "google/cloud/internal/getenv.h"
#include <iostream>
#include <string>
#include <thread>

namespace {

void PerformSomeOperations(google::cloud::storage::Client client,
                           std::string const& bucket_name,
                           std::string const& object_name) {
  namespace gcs = ::google::cloud::storage;
  auto constexpr kText = "The quick brown fox jumps over the lazy dog\n";

  auto object = client.InsertObject(bucket_name, object_name, kText).value();
  for (auto&& o : client.ListObjects(bucket_name)) {
    if (!o) throw std::move(o).status();
    if (o->name() == object_name) break;
  }
  auto status = client.DeleteObject(bucket_name, object_name,
                                    gcs::Generation(object.generation()));
  if (!status.ok()) throw std::runtime_error(status.message());
}

void DefaultClient(std::vector<std::string> const& argv) {
  namespace examples = ::google::cloud::storage::examples;
  if ((argv.size() == 1 && argv[0] == "--help") || argv.size() != 2) {
    throw examples::Usage{
        "default-client"
        " <bucket-name> <object-name>"};
  }
  //! [default-client]
  namespace gcs = ::google::cloud::storage;
  [](std::string const& bucket_name, std::string const& object_name) {
    auto client = gcs::Client();
    PerformSomeOperations(client, bucket_name, object_name);
  }
  //! [default-client]
  (argv.at(0), argv.at(1));
}

void SetClientEndpoint(std::vector<std::string> const& argv) {
  namespace examples = ::google::cloud::storage::examples;
  if ((argv.size() == 1 && argv[0] == "--help") || argv.size() != 2) {
    throw examples::Usage{
        "set-client-endpoint"
        " <bucket-name> <object-name>"};
  }
  //! [START storage_set_client_endpoint] [set-client-endpoint]
  namespace g = ::google::cloud;
  namespace gcs = ::google::cloud::storage;
  [](std::string const& bucket_name, std::string const& object_name) {
    // NOTE: the CLOUD_STORAGE_EMULATOR_HOST environment variable overrides any
    //     value provided here.
    auto client = gcs::Client(g::Options{}.set<gcs::RestEndpointOption>(
        "https://storage.googleapis.com"));
    PerformSomeOperations(client, bucket_name, object_name);
  }
  //! [END storage_set_client_endpoint] [set-client-endpoint]
  (argv.at(0), argv.at(1));
}

void ExplicitADCs(std::vector<std::string> const& argv) {
  namespace examples = ::google::cloud::storage::examples;
  if ((argv.size() == 1 && argv[0] == "--help") || argv.size() != 2) {
    throw examples::Usage{
        "explicit-adcs"
        " <bucket-name> <object-name>"};
  }
  //! [explicit-adcs]
  namespace gcs = ::google::cloud::storage;
  using ::google::cloud::Options;
  using ::google::cloud::UnifiedCredentialsOption;
  [](std::string const& bucket_name, std::string const& object_name) {
    auto client = gcs::Client(Options{}.set<UnifiedCredentialsOption>(
        google::cloud::MakeGoogleDefaultCredentials()));
    PerformSomeOperations(client, bucket_name, object_name);
  }
  //! [explicit-adcs]
  (argv.at(0), argv.at(1));
}

void ServiceAccountKeyfile(std::vector<std::string> const& argv) {
  namespace examples = ::google::cloud::storage::examples;
  if ((argv.size() == 1 && argv[0] == "--help") || argv.size() != 3) {
    throw examples::Usage{
        "service-account-keyfile-json"
        " <service-account-file> <bucket-name> <object-name>"};
  }
  //! [service-account-keyfile]
  namespace gcs = ::google::cloud::storage;
  [](std::string const& filename, std::string const& bucket_name,
     std::string const& object_name) {
    auto is = std::ifstream(filename);
    is.exceptions(std::ios::badbit);
    auto json_string =
        std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
    auto credentials =
        google::cloud::MakeServiceAccountCredentials(json_string);
    auto client = gcs::Client(
        google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
            credentials));
    PerformSomeOperations(client, bucket_name, object_name);
  }
  //! [service-account-keyfile]
  (argv.at(0), argv.at(1), argv.at(2));
}

void RunAll(std::vector<std::string> const& argv) {
  namespace examples = ::google::cloud::storage::examples;
  namespace gcs = ::google::cloud::storage;

  if (!argv.empty()) throw examples::Usage{"auto"};
  examples::CheckEnvironmentVariablesAreSet({
      "GOOGLE_CLOUD_PROJECT",
  });
  auto const project_id =
      google::cloud::internal::GetEnv("GOOGLE_CLOUD_PROJECT").value();
  auto generator = google::cloud::internal::DefaultPRNG(std::random_device{}());
  auto const bucket_name = examples::MakeRandomBucketName(generator);
  auto client = gcs::Client();
  std::cout << "\nCreating bucket to run the example (" << bucket_name << ")"
            << std::endl;
  (void)client
      .CreateBucketForProject(bucket_name, project_id, gcs::BucketMetadata{},
                              examples::CreateBucketOptions())
      .value();
  // In GCS a single project cannot create or delete buckets more often than
  // once every two seconds. We will pause until that time before deleting the
  // bucket.
  auto const delete_after =
      std::chrono::steady_clock::now() + std::chrono::seconds(2);

  std::cout << "\nRunning DefaultClient()" << std::endl;
  auto const object_name = examples::MakeRandomObjectName(generator, "object-");
  DefaultClient({bucket_name, object_name});

  std::cout << "\nRunning SetClientEndpoint()" << std::endl;
  SetClientEndpoint({bucket_name, object_name});

  std::cout << "\nRunning ExplicitADCs()" << std::endl;
  ExplicitADCs({bucket_name, object_name});

  auto const filename = google::cloud::internal::GetEnv(
      "GOOGLE_CLOUD_CPP_STORAGE_TEST_KEY_FILE_JSON");
  if (filename.has_value()) {
    std::cout << "\nRunning ServiceAccountKeyfileJson()" << std::endl;
    ServiceAccountKeyfile({*filename, bucket_name, object_name});
  }

  if (!examples::UsingEmulator()) std::this_thread::sleep_until(delete_after);
  (void)examples::RemoveBucketAndContents(client, bucket_name);
}

}  // namespace

int main(int argc, char* argv[]) {
  namespace examples = ::google::cloud::storage::examples;
  examples::Example example({
      {"default-client", DefaultClient},
      {"explicit-adcs", ExplicitADCs},
      {"service-account-keyfile", ServiceAccountKeyfile},
      {"set-client-endpoint", SetClientEndpoint},
      {"auto", RunAll},
  });
  return example.Run(argc, argv);
}