GCP Observability Logging: Base64 Encode metadata, message and status-details (#32184)

* GCP Observability Logging: Base64 Encode metadata, message and status-details

* Use padding for message and status-details

src/cpp/ext/gcp/observability_logging_sink.cc

@@ -26,6 +26,8 @@
 
 #include <google/protobuf/timestamp.pb.h>
 
+#include "absl/strings/escaping.h"
+#include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
 #include "absl/types/optional.h"
@@ -34,6 +36,7 @@
 #include "google/logging/v2/logging.grpc.pb.h"
 #include "google/logging/v2/logging.pb.h"
 
+#include <grpc/support/log.h>
 #include <grpc/support/time.h>
 #include <grpcpp/grpcpp.h>
 #include <grpcpp/security/credentials.h>
@@ -134,8 +137,13 @@ void PayloadToJsonStructProto(LoggingSink::Entry::Payload payload,
     auto* metadata_proto =
         (*payload_proto->mutable_fields())["metadata"].mutable_struct_value();
     for (auto& metadata : payload.metadata) {
-      (*metadata_proto->mutable_fields())[metadata.first].set_string_value(
-          std::move(metadata.second));
+      if (absl::EndsWith(metadata.first, "-bin")) {
+        (*metadata_proto->mutable_fields())[metadata.first].set_string_value(
+            absl::WebSafeBase64Escape(metadata.second));
+      } else {
+        (*metadata_proto->mutable_fields())[metadata.first].set_string_value(
+            std::move(metadata.second));
+      }
     }
   }
   if (payload.timeout != grpc_core::Duration::Zero()) {
@@ -152,7 +160,7 @@ void PayloadToJsonStructProto(LoggingSink::Entry::Payload payload,
   }
   if (!payload.status_details.empty()) {
     (*payload_proto->mutable_fields())["statusDetails"].set_string_value(
-        std::move(payload.status_details));
+        absl::Base64Escape(payload.status_details));
   }
   if (payload.message_length != 0) {
     (*payload_proto->mutable_fields())["messageLength"].set_number_value(
@@ -160,7 +168,7 @@ void PayloadToJsonStructProto(LoggingSink::Entry::Payload payload,
   }
   if (!payload.message.empty()) {
     (*payload_proto->mutable_fields())["message"].set_string_value(
-        std::move(payload.message));
+        absl::Base64Escape(payload.message));
   }
 }
 
@@ -264,14 +272,17 @@ void ObservabilityLoggingSink::LogEntry(Entry entry) {
   proto_entry->mutable_timestamp()->set_nanos(timespec.tv_nsec);
   // TODO(yashykt): Check if we need to fill receive timestamp
   EntryToJsonStructProto(std::move(entry), proto_entry->mutable_json_payload());
-  stub_->async()->WriteLogEntries(&(call->context), &(call->request),
-                                  &(call->response), [call](Status status) {
-                                    if (!status.ok()) {
-                                      // TODO(yashykt): Log the contents of the
-                                      // request on a failure.
-                                    }
-                                    delete call;
-                                  });
+  stub_->async()->WriteLogEntries(
+      &(call->context), &(call->request), &(call->response),
+      [call](Status status) {
+        if (!status.ok()) {
+          // TODO(yashykt): Log the contents of the
+          // request on a failure.
+          gpr_log(GPR_ERROR, "GCP Observability Logging Error %d: %s",
+                  status.error_code(), status.error_message().c_str());
+        }
+        delete call;
+      });
 }
 
 ObservabilityLoggingSink::Configuration::Configuration(

test/cpp/ext/gcp/observability_logging_sink_test.cc

@@ -16,6 +16,8 @@
 
 #include "src/cpp/ext/gcp/observability_logging_sink.h"
 
+#include "absl/strings/escaping.h"
+#include "absl/strings/str_format.h"
 #include "gmock/gmock.h"
 #include "google/protobuf/text_format.h"
 #include "gtest/gtest.h"
@@ -554,7 +556,7 @@ TEST(EntryToJsonStructTest, ClientMessage) {
   EntryToJsonStructProto(std::move(entry), &proto);
   std::string output;
   ::google::protobuf::TextFormat::PrintToString(proto, &output);
-  const char* pb_str =
+  std::string pb_str = absl::StrFormat(
       "fields {\n"
       "  key: \"authority\"\n"
       "  value {\n"
@@ -586,7 +588,7 @@ TEST(EntryToJsonStructTest, ClientMessage) {
       "      fields {\n"
       "        key: \"message\"\n"
       "        value {\n"
-      "          string_value: \"hello\"\n"
+      "          string_value: \"%s\"\n"
       "        }\n"
       "      }\n"
       "      fields {\n"
@@ -640,7 +642,8 @@ TEST(EntryToJsonStructTest, ClientMessage) {
       "  value {\n"
       "    string_value: \"CLIENT_MESSAGE\"\n"
       "  }\n"
-      "}\n";
+      "}\n",
+      absl::Base64Escape("hello"));
   EXPECT_EQ(output, pb_str);
 }
 
@@ -663,7 +666,7 @@ TEST(EntryToJsonStructTest, ServerMessage) {
   EntryToJsonStructProto(std::move(entry), &proto);
   std::string output;
   ::google::protobuf::TextFormat::PrintToString(proto, &output);
-  const char* pb_str =
+  std::string pb_str = absl::StrFormat(
       "fields {\n"
       "  key: \"authority\"\n"
       "  value {\n"
@@ -695,7 +698,7 @@ TEST(EntryToJsonStructTest, ServerMessage) {
       "      fields {\n"
       "        key: \"message\"\n"
       "        value {\n"
-      "          string_value: \"world\"\n"
+      "          string_value: \"%s\"\n"
       "        }\n"
       "      }\n"
       "      fields {\n"
@@ -749,7 +752,8 @@ TEST(EntryToJsonStructTest, ServerMessage) {
       "  value {\n"
       "    string_value: \"SERVER_MESSAGE\"\n"
       "  }\n"
-      "}\n";
+      "}\n",
+      absl::Base64Escape("world"));
   EXPECT_EQ(output, pb_str);
 }