Merge branch 'main' into nit-histogram-var-fix

CHANGELOG.md

@@ -22,6 +22,7 @@ Increment the:
 * [CI] Enforce copyright check in CI [#1965](https://github.com/open-telemetry/opentelemetry-cpp/pull/1965)
 * [SEMANTIC CONVENTIONS] Upgrade to version 1.18.0
   [#1974](https://github.com/open-telemetry/opentelemetry-cpp/pull/1974)
+* Fix Prometheus server crash on listening to already used port [#1986](https://github.com/open-telemetry/opentelemetry-cpp/pull/1986)
 
 ## [1.8.2] 2023-01-31
 

examples/prometheus/README.md

@@ -11,31 +11,12 @@
 
 ## Export metrics from the application
 
-It is highly recommended to go over the [ostream-metrics](../metrics_simple/README.md)
-doc before following along this document.
-
 Run the application with:
 
 ```sh
 bazel run //examples/prometheus:prometheus_example
 ```
 
-The main difference between the [ostream-metrics](../metrics_simple/README.md)
-example with this one is that the line below is replaced:
-
-```cpp
-std::unique_ptr<metric_sdk::PushMetricExporter> exporter{
-    new exportermetrics::OStreamMetricExporter};
-
-```
-
-with
-
-```cpp
-std::unique_ptr<metrics_sdk::PushMetricExporter> exporter{
-    new metrics_exporter::PrometheusExporter(opts)};
-```
-
 OpenTelemetry `PrometheusExporter` will export
 data via the endpoint defined by
 `metrics_exporter::PrometheusExporterOptions::url`,
@@ -46,8 +27,7 @@ graph LR
 
 subgraph SDK
   MeterProvider
-  MetricReader[PeriodicExportingMetricReader]
-  PrometheusExporter["PrometheusExporter<br/>(http://localhost:9464/)"]
+  MetricReader["PrometheusExporter<br/>(http://localhost:9464/)"]
 end
 
 subgraph API
@@ -56,7 +36,7 @@ end
 
 Instrument --> | Measurements | MeterProvider
 
-MeterProvider --> | Metrics | MetricReader --> | Pull | PrometheusExporter
+MeterProvider --> | Metrics | MetricReader
 ```
 
 Also, for our learning purpose, we use a while-loop to keep recoring random

examples/prometheus/main.cc

@@ -78,7 +78,7 @@ void CleanupMetrics()
 int main(int argc, char **argv)
 {
   std::string example_type;
-  std::string addr{"localhost:8080"};
+  std::string addr{"localhost:9464"};
   if (argc == 1)
   {
     std::puts("usage: $prometheus_example <example type> <url>");

exporters/prometheus/src/collector.cc

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "opentelemetry/exporters/prometheus/collector.h"
+#include "opentelemetry/sdk/common/global_log_handler.h"
 
 namespace metric_sdk = opentelemetry::sdk::metrics;
 
@@ -27,6 +28,9 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
 {
   if (reader_->IsShutdown())
   {
+    OTEL_INTERNAL_LOG_WARN(
+        "[Prometheus Exporter] Collect: "
+        "Exporter is shutdown, can not invoke collect operation.");
     return {};
   }
   collection_lock_.lock();

exporters/prometheus/src/exporter.cc

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "opentelemetry/exporters/prometheus/exporter.h"
+#include "opentelemetry/sdk/common/global_log_handler.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 
@@ -16,7 +17,19 @@ namespace metrics
  */
 PrometheusExporter::PrometheusExporter(const PrometheusExporterOptions &options) : options_(options)
 {
-  exposer_   = std::unique_ptr<::prometheus::Exposer>(new ::prometheus::Exposer{options_.url});
+  try
+  {
+    exposer_ = std::unique_ptr<::prometheus::Exposer>(new ::prometheus::Exposer{options_.url});
+  }
+  catch (const std::exception &ex)
+  {
+    exposer_.reset(nullptr);
+    OTEL_INTERNAL_LOG_ERROR("[Prometheus Exporter] "
+                            << "Can't initialize prometheus exposer with endpoint: " << options_.url
+                            << "\nError: " << ex.what());
+    Shutdown();  // set MetricReader in shutdown state.
+    return;
+  }
   collector_ = std::shared_ptr<PrometheusCollector>(new PrometheusCollector(this));
 
   exposer_->RegisterCollectable(collector_);
@@ -36,7 +49,8 @@ bool PrometheusExporter::OnForceFlush(std::chrono::microseconds /* timeout */) n
 
 bool PrometheusExporter::OnShutDown(std::chrono::microseconds /* timeout */) noexcept
 {
-  exposer_->RemoveCollectable(collector_);
+  if (exposer_ != nullptr)
+    exposer_->RemoveCollectable(collector_);
   return true;
 }
 

sdk/src/logs/logger.cc

@@ -40,6 +40,9 @@ nostd::unique_ptr<opentelemetry::logs::LogRecord> Logger::CreateLogRecord() noex
   }
 
   auto recordable = context_->GetProcessor().MakeRecordable();
+
+  recordable->SetObservedTimestamp(std::chrono::system_clock::now());
+
   if (include_trace_context_ &&
       opentelemetry::context::RuntimeContext::GetCurrent().HasKey(opentelemetry::trace::kSpanKey))
   {

sdk/test/logs/logger_sdk_test.cc

@@ -3,6 +3,7 @@
 
 #ifdef ENABLE_LOGS_PREVIEW
 
+#  include <chrono>
 #  include <string>
 
 #  include "opentelemetry/nostd/string_view.h"
@@ -43,7 +44,16 @@ class MockLogRecordable final : public opentelemetry::sdk::logs::Recordable
 public:
   void SetTimestamp(opentelemetry::common::SystemTimestamp) noexcept override {}
 
-  void SetObservedTimestamp(opentelemetry::common::SystemTimestamp) noexcept override {}
+  void SetObservedTimestamp(
+      opentelemetry::common::SystemTimestamp observed_timestamp) noexcept override
+  {
+    observed_timestamp_ = observed_timestamp;
+  }
+
+  const opentelemetry::common::SystemTimestamp &GetObservedTimestamp() const noexcept
+  {
+    return observed_timestamp_;
+  }
 
   opentelemetry::logs::Severity GetSeverity() const noexcept { return severity_; }
 
@@ -121,13 +131,14 @@ class MockLogRecordable final : public opentelemetry::sdk::logs::Recordable
 
   void CopyFrom(const MockLogRecordable &other)
   {
-    severity_     = other.severity_;
-    body_         = other.body_;
-    trace_id_     = other.trace_id_;
-    span_id_      = other.span_id_;
-    trace_flags_  = other.trace_flags_;
-    event_name_   = other.event_name_;
-    event_domain_ = other.event_domain_;
+    severity_           = other.severity_;
+    body_               = other.body_;
+    trace_id_           = other.trace_id_;
+    span_id_            = other.span_id_;
+    trace_flags_        = other.trace_flags_;
+    event_name_         = other.event_name_;
+    event_domain_       = other.event_domain_;
+    observed_timestamp_ = other.observed_timestamp_;
   }
 
 private:
@@ -138,6 +149,8 @@ class MockLogRecordable final : public opentelemetry::sdk::logs::Recordable
   opentelemetry::trace::TraceFlags trace_flags_;
   std::string event_name_;
   std::string event_domain_;
+  opentelemetry::common::SystemTimestamp observed_timestamp_ =
+      std::chrono::system_clock::from_time_t(0);
 };
 
 class MockProcessor final : public LogRecordProcessor
@@ -196,6 +209,8 @@ TEST(LoggerSDK, LogToAProcessor)
   }
   opentelemetry::trace::Scope trace_scope{include_span};
 
+  auto now = std::chrono::system_clock::now();
+
   auto sdk_logger = static_cast<opentelemetry::sdk::logs::Logger *>(logger.get());
   ASSERT_EQ(sdk_logger->GetInstrumentationScope().GetName(), "opentelelemtry_library");
   ASSERT_EQ(sdk_logger->GetInstrumentationScope().GetVersion(), "");
@@ -226,6 +241,10 @@ TEST(LoggerSDK, LogToAProcessor)
   std::string span_id_text_in_span{span_id_in_span, sizeof(span_id_in_span)};
   ASSERT_EQ(trace_id_text_in_logger, trace_id_text_in_span);
   ASSERT_EQ(span_id_text_in_logger, span_id_text_in_span);
+
+  ASSERT_GE(
+      static_cast<std::chrono::system_clock::time_point>(shared_recordable->GetObservedTimestamp()),
+      now);
 }
 
 TEST(LoggerSDK, EventLog)