Prometheus exporter does not add _total suffixes to counters

[dashpole]

What is the expected behavior?

From https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/compatibility/prometheus_and_openmetrics.md#sums:

If the metric name for monotonic Sum metric points does not end in a suffix of _total a suffix of _total MUST be added by default, otherwise the name MUST remain unchanged. Exporters SHOULD provide a configuration option to disable the addition of _total suffixes.

What is the actual behavior?

Based on the unit test here:

opentelemetry-cpp/exporters/prometheus/test/exporter_utils_test.cc

Lines 107 to 119 in f52ec6c

	TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerCounter)
	{
	metric_sdk::ResourceMetrics metrics_data = CreateSumPointData();
	auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
	ASSERT_EQ(translated.size(), 1);
	auto metric1 = translated[0];
	std::vector<int> vals = {10};
	assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter, 1,
	vals);
	}

The counter metric does not have a _total suffix appended.

[marcalff]

Thanks for the report.

@esigo Sounds in the same area as #2213, please take a look.

[github-actions]

This issue was marked as stale due to lack of activity.

[dashpole]

Fixed by #2213