fix: gcp bugs

1. Invalid release up of the pool client handle.
2. add a missing header for gcp metadata request.

Signed-off-by: Roman Gershman <romange@gmail.com>

Author: romange

util/cloud/gcp/gcs.cc

@@ -144,9 +144,11 @@ io::Result<TokenTtl> ParseTokenResponse(std::string&& response) {
   return result;
 }
 
+static constexpr string_view kMetaDataHost = "metadata.google.internal"sv;
+
 error_code ConfigureMetadataClient(fb2::ProactorBase* pb, http::Client* client) {
   client->set_connect_timeout_ms(1000);
-  static const char kMetaDataHost[] = "metadata.google.internal";
+
   return client->Connect(kMetaDataHost, "80");
 }
 
@@ -158,6 +160,7 @@ error_code ReadGCPConfigFromMetadata(fb2::ProactorBase* pb, string* account_id,
   const char kEmailUrl[] = "/computeMetadata/v1/instance/service-accounts/default/email";
   h2::request<h2::empty_body> req{h2::verb::get, kEmailUrl, 11};
   req.set("Metadata-Flavor", "Google");
+  req.set(h2::field::host, kMetaDataHost.data());
 
   h2::response<h2::string_body> resp;
   RETURN_ERROR(client.Send(req, &resp));
@@ -270,6 +273,8 @@ error_code GCPCredsProvider::RefreshToken() {
 
     h2::request<h2::empty_body> req{h2::verb::get, kInstanceTokenUrl, 11};
     req.set("Metadata-Flavor", "Google");
+    req.set(h2::field::host, kMetaDataHost.data());
+
     RETURN_ERROR(client.Send(req, &resp));
   } else {
     constexpr char kDomain[] = "oauth2.googleapis.com";

util/cloud/gcp/gcs_file.cc

@@ -3,6 +3,7 @@
 
 #include "util/cloud/gcp/gcs_file.h"
 
+#include <absl/cleanup/cleanup.h>
 #include <absl/strings/str_cat.h>
 #include <absl/strings/strip.h>
 
@@ -93,7 +94,7 @@ class GcsWriteFile : public detail::AbstractStorageFile {
   GcsWriteFileOptions opts_;
 };
 
-class GcsReadFile final : public io::ReadonlyFile  {
+class GcsReadFile final : public io::ReadonlyFile {
  public:
   // does not own gcs object, only wraps it with ReadonlyFile interface.
   GcsReadFile(string read_obj_url, const GcsReadFileOptions& opts)
@@ -193,7 +194,6 @@ error_code GcsWriteFile::Close() {
   return {};
 }
 
-
 error_code GcsWriteFile::Upload() {
   size_t body_size = body_mb_.size();
   CHECK_GT(body_size, 0u);
@@ -317,11 +317,17 @@ io::Result<io::WriteFile*> OpenWriteGcsFile(const string& bucket, const string&
 
   RobustSender sender(opts.pool, opts.creds_provider);
   RobustSender::SenderResult send_res;
-  error_code ec = sender.Send(3, &empty_req, &send_res);
-  if (ec) {
+  absl::Cleanup cleanup([&] {
     if (opts.pool_owned) {
+      // We must reset the client handle before deleting the pool that owns it.
+      send_res.client_handle.reset();
       delete opts.pool;
     }
+  });
+
+  error_code ec = sender.Send(3, &empty_req, &send_res);
+
+  if (ec) {
     return nonstd::make_unexpected(ec);
   }
 
@@ -330,11 +336,9 @@ io::Result<io::WriteFile*> OpenWriteGcsFile(const string& bucket, const string&
   auto it = headers.find(h2::field::location);
   if (it == headers.end()) {
     LOG(ERROR) << "Could not find location in " << headers;
-    if (opts.pool_owned) {
-      delete opts.pool;
-    }
     return nonstd::make_unexpected(make_error_code(errc::connection_refused));
   }
+  std::move(cleanup).Cancel();
 
   return new GcsWriteFile(key, detail::FromBoostSV(it->value()), opts);
 }