[DOC] Add readme and examples for OTLP FILE exporters. (#2638)

examples/otlp/BUILD

@@ -37,6 +37,24 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "example_otlp_file",
+    srcs = [
+        "file_main.cc",
+    ],
+    tags = [
+        "examples",
+        "otlp",
+        "otlp_file",
+    ],
+    deps = [
+        "//api",
+        "//examples/common/foo_library:common_foo_library",
+        "//exporters/otlp:otlp_file_exporter",
+        "//sdk/src/trace",
+    ],
+)
+
 cc_binary(
     name = "example_otlp_http_log",
     srcs = [
@@ -75,6 +93,25 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "example_otlp_file_log",
+    srcs = [
+        "file_log_main.cc",
+    ],
+    tags = [
+        "examples",
+        "otlp",
+        "otlp_file_log",
+    ],
+    deps = [
+        "//api",
+        "//examples/common/logs_foo_library:common_logs_foo_library",
+        "//exporters/otlp:otlp_file_exporter",
+        "//exporters/otlp:otlp_file_log_record_exporter",
+        "//sdk/src/trace",
+    ],
+)
+
 cc_binary(
     name = "example_otlp_grpc_metric",
     srcs = [
@@ -112,3 +149,22 @@ cc_binary(
         "//sdk/src/metrics",
     ],
 )
+
+cc_binary(
+    name = "example_otlp_file_metric",
+    srcs = [
+        "file_metric_main.cc",
+    ],
+    tags = [
+        "examples",
+        "metrics",
+        "otlp",
+    ],
+    deps = [
+        "//api",
+        "//examples/common/metrics_foo_library:common_metrics_foo_library",
+        "//exporters/otlp:otlp_file_exporter",
+        "//exporters/otlp:otlp_file_metric_exporter",
+        "//sdk/src/metrics",
+    ],
+)

examples/otlp/CMakeLists.txt

@@ -100,3 +100,47 @@ if(WITH_OTLP_HTTP)
   endif()
 
 endif()
+
+if(WITH_OTLP_FILE)
+  # TRACE
+
+  add_executable(example_otlp_file file_main.cc)
+
+  target_link_libraries(example_otlp_file ${CMAKE_THREAD_LIBS_INIT}
+                        common_foo_library)
+
+  if(DEFINED OPENTELEMETRY_BUILD_DLL)
+    target_link_libraries(example_otlp_file opentelemetry_cpp)
+  else()
+    target_link_libraries(example_otlp_file opentelemetry_trace
+                          opentelemetry_exporter_otlp_file)
+  endif()
+
+  # METRIC
+
+  add_executable(example_otlp_file_metric file_metric_main.cc)
+
+  target_link_libraries(example_otlp_file_metric ${CMAKE_THREAD_LIBS_INIT}
+                        common_metrics_foo_library)
+
+  if(DEFINED OPENTELEMETRY_BUILD_DLL)
+    target_link_libraries(example_otlp_file_metric opentelemetry_cpp)
+  else()
+    target_link_libraries(example_otlp_file_metric opentelemetry_metrics
+                          opentelemetry_exporter_otlp_file_metric)
+  endif()
+
+  # LOG
+
+  add_executable(example_otlp_file_log file_log_main.cc)
+
+  target_link_libraries(example_otlp_file_log ${CMAKE_THREAD_LIBS_INIT}
+                        common_logs_foo_library)
+  if(DEFINED OPENTELEMETRY_BUILD_DLL)
+    target_link_libraries(example_otlp_file_log opentelemetry_cpp)
+  else()
+    target_link_libraries(
+      example_otlp_file_log opentelemetry_trace opentelemetry_logs
+      opentelemetry_exporter_otlp_file opentelemetry_exporter_otlp_file_log)
+  endif()
+endif()

examples/otlp/file_log_main.cc

@@ -0,0 +1,124 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "opentelemetry/exporters/otlp/otlp_file_client_options.h"
+#include "opentelemetry/exporters/otlp/otlp_file_exporter_factory.h"
+#include "opentelemetry/exporters/otlp/otlp_file_exporter_options.h"
+#include "opentelemetry/exporters/otlp/otlp_file_log_record_exporter_factory.h"
+#include "opentelemetry/exporters/otlp/otlp_file_log_record_exporter_options.h"
+#include "opentelemetry/logs/provider.h"
+#include "opentelemetry/sdk/logs/exporter.h"
+#include "opentelemetry/sdk/logs/logger_provider_factory.h"
+#include "opentelemetry/sdk/logs/processor.h"
+#include "opentelemetry/sdk/logs/simple_log_record_processor_factory.h"
+#include "opentelemetry/sdk/trace/exporter.h"
+#include "opentelemetry/sdk/trace/processor.h"
+#include "opentelemetry/sdk/trace/simple_processor_factory.h"
+#include "opentelemetry/sdk/trace/tracer_provider_factory.h"
+#include "opentelemetry/trace/provider.h"
+
+// sdk::TracerProvider and sdk::LoggerProvider is just used to call ForceFlush and prevent to cancel
+// running exportings when destroy and shutdown exporters.It's optional to users.
+#include "opentelemetry/sdk/logs/logger_provider.h"
+#include "opentelemetry/sdk/trace/tracer_provider.h"
+
+#include <iostream>
+#include <string>
+#include <utility>
+
+#ifdef BAZEL_BUILD
+#  include "examples/common/logs_foo_library/foo_library.h"
+#else
+#  include "logs_foo_library/foo_library.h"
+#endif
+
+namespace trace     = opentelemetry::trace;
+namespace nostd     = opentelemetry::nostd;
+namespace otlp      = opentelemetry::exporter::otlp;
+namespace logs_sdk  = opentelemetry::sdk::logs;
+namespace logs      = opentelemetry::logs;
+namespace trace_sdk = opentelemetry::sdk::trace;
+
+namespace
+{
+opentelemetry::exporter::otlp::OtlpFileExporterOptions opts;
+opentelemetry::exporter::otlp::OtlpFileLogRecordExporterOptions log_opts;
+void InitTracer()
+{
+  // Create OTLP exporter instance
+  auto exporter  = otlp::OtlpFileExporterFactory::Create(opts);
+  auto processor = trace_sdk::SimpleSpanProcessorFactory::Create(std::move(exporter));
+  std::shared_ptr<opentelemetry::trace::TracerProvider> provider =
+      trace_sdk::TracerProviderFactory::Create(std::move(processor));
+  // Set the global trace provider
+  trace::Provider::SetTracerProvider(provider);
+}
+
+void CleanupTracer()
+{
+  // We call ForceFlush to prevent to cancel running exportings, It's optional.
+  opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider> provider =
+      trace::Provider::GetTracerProvider();
+  if (provider)
+  {
+    static_cast<trace_sdk::TracerProvider *>(provider.get())->ForceFlush();
+  }
+
+  std::shared_ptr<opentelemetry::trace::TracerProvider> none;
+  trace::Provider::SetTracerProvider(none);
+}
+
+void InitLogger()
+{
+  // Create OTLP exporter instance
+  auto exporter  = otlp::OtlpFileLogRecordExporterFactory::Create(log_opts);
+  auto processor = logs_sdk::SimpleLogRecordProcessorFactory::Create(std::move(exporter));
+  nostd::shared_ptr<logs::LoggerProvider> provider(
+      logs_sdk::LoggerProviderFactory::Create(std::move(processor)));
+
+  opentelemetry::logs::Provider::SetLoggerProvider(provider);
+}
+
+void CleanupLogger()
+{
+  // We call ForceFlush to prevent to cancel running exportings, It's optional.
+  opentelemetry::nostd::shared_ptr<logs::LoggerProvider> provider =
+      logs::Provider::GetLoggerProvider();
+  if (provider)
+  {
+    static_cast<logs_sdk::LoggerProvider *>(provider.get())->ForceFlush();
+  }
+
+  nostd::shared_ptr<logs::LoggerProvider> none;
+  opentelemetry::logs::Provider::SetLoggerProvider(none);
+}
+}  // namespace
+
+int main(int argc, char *argv[])
+{
+  if (argc > 1)
+  {
+    opentelemetry::exporter::otlp::OtlpFileClientFileSystemOptions fs_backend;
+    fs_backend.file_pattern = argv[1];
+    opts.backend_options    = fs_backend;
+    if (argc > 2)
+    {
+      opentelemetry::exporter::otlp::OtlpFileClientFileSystemOptions logs_fs_backend;
+      logs_fs_backend.file_pattern = argv[2];
+      log_opts.backend_options     = logs_fs_backend;
+    }
+    else
+    {
+      log_opts.backend_options = std::ref(std::cout);
+    }
+  }
+  else
+  {
+    opts.backend_options = std::ref(std::cout);
+  }
+  InitLogger();
+  InitTracer();
+  foo_library();
+  CleanupTracer();
+  CleanupLogger();
+}

examples/otlp/file_main.cc

@@ -0,0 +1,71 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "opentelemetry/exporters/otlp/otlp_file_exporter_factory.h"
+#include "opentelemetry/sdk/trace/processor.h"
+#include "opentelemetry/sdk/trace/simple_processor_factory.h"
+#include "opentelemetry/sdk/trace/tracer_provider_factory.h"
+#include "opentelemetry/trace/provider.h"
+
+// sdk::TracerProvider is just used to call ForceFlush and prevent to cancel running exportings when
+// destroy and shutdown exporters.It's optional to users.
+#include "opentelemetry/sdk/trace/tracer_provider.h"
+
+#include <iostream>
+#include <string>
+#include <utility>
+
+#ifdef BAZEL_BUILD
+#  include "examples/common/foo_library/foo_library.h"
+#else
+#  include "foo_library/foo_library.h"
+#endif
+
+namespace trace     = opentelemetry::trace;
+namespace trace_sdk = opentelemetry::sdk::trace;
+namespace otlp      = opentelemetry::exporter::otlp;
+
+namespace
+{
+opentelemetry::exporter::otlp::OtlpFileExporterOptions opts;
+void InitTracer()
+{
+  // Create OTLP exporter instance
+  auto exporter  = otlp::OtlpFileExporterFactory::Create(opts);
+  auto processor = trace_sdk::SimpleSpanProcessorFactory::Create(std::move(exporter));
+  std::shared_ptr<opentelemetry::trace::TracerProvider> provider =
+      trace_sdk::TracerProviderFactory::Create(std::move(processor));
+  // Set the global trace provider
+  trace::Provider::SetTracerProvider(provider);
+}
+
+void CleanupTracer()
+{
+  // We call ForceFlush to prevent to cancel running exportings, It's optional.
+  opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider> provider =
+      trace::Provider::GetTracerProvider();
+  if (provider)
+  {
+    static_cast<trace_sdk::TracerProvider *>(provider.get())->ForceFlush();
+  }
+
+  std::shared_ptr<opentelemetry::trace::TracerProvider> none;
+  trace::Provider::SetTracerProvider(none);
+}
+}  // namespace
+
+int main(int argc, char *argv[])
+{
+  if (argc > 1)
+  {
+    opentelemetry::exporter::otlp::OtlpFileClientFileSystemOptions fs_backend;
+    fs_backend.file_pattern = argv[1];
+    opts.backend_options    = fs_backend;
+  }
+  // Removing this line will leave the default noop TracerProvider in place.
+  InitTracer();
+
+  foo_library();
+
+  CleanupTracer();
+}