add ignore_patterns config

datadog_checks_base/datadog_checks/base/checks/openmetrics/mixins.py

@@ -146,6 +146,15 @@ def create_scraper_configuration(self, instance=None):
         # very high cardinality. Metrics included in this list will be silently
         # skipped without a 'Unable to handle metric' debug line in the logs
         config['ignore_metrics'] = instance.get('ignore_metrics', default_instance.get('ignore_metrics', []))
+        config['_ignored_metrics'] = set()
+        config['_ignored_patterns'] = set()
+
+        # Separate ignored metric names and ignored patterns in different sets for faster lookup later
+        for metric in config['ignore_metrics']:
+            if '*' in metric:
+                config['_ignored_patterns'].add(metric)
+            else:
+                config['_ignored_metrics'].add(metric)
 
         # If you want to send the buckets as tagged values when dealing with histograms,
         # set send_histograms_buckets to True, set to False otherwise.
@@ -506,12 +515,22 @@ def process_metric(self, metric, scraper_config, metric_transformers=None):
         # If targeted metric, store labels
         self._store_labels(metric, scraper_config)
 
-        if metric.name in scraper_config['ignore_metrics']:
+        if metric.name in scraper_config['_ignored_metrics']:
             self._send_telemetry_counter(
                 self.TELEMETRY_COUNTER_METRICS_IGNORE_COUNT, len(metric.samples), scraper_config
             )
             return  # Ignore the metric
 
+        for ignore_pattern in scraper_config['_ignored_patterns']:
+            if fnmatchcase(metric.name, ignore_pattern):
+                # Metric must be ignored
+                # Cache the ignored metric name to avoid calling fnmatchcase in the next check run
+                scraper_config['_ignored_metrics'].add(metric.name)
+                self._send_telemetry_counter(
+                    self.TELEMETRY_COUNTER_METRICS_IGNORE_COUNT, len(metric.samples), scraper_config
+                )
+                return  # Ignore the metric
+
         self._send_telemetry_counter(self.TELEMETRY_COUNTER_METRICS_PROCESS_COUNT, len(metric.samples), scraper_config)
 
         if self._filter_metric(metric, scraper_config):

datadog_checks_base/tests/test_openmetrics.py

@@ -1458,6 +1458,75 @@ def test_ignore_metric(aggregator, mocked_prometheus_check, ref_gauge):
     aggregator.assert_metric('prometheus.process.vm.bytes', count=0)
 
 
+def test_ignore_metric_wildcard(aggregator, mocked_prometheus_check, ref_gauge):
+    """
+    Test that metric that matched the ignored metrics pattern is properly discarded.
+    """
+    check = mocked_prometheus_check
+    instance = copy.deepcopy(PROMETHEUS_CHECK_INSTANCE)
+    instance['ignore_metrics'] = ['process_virtual_*']
+
+    config = check.get_scraper_config(instance)
+    config['_dry_run'] = False
+
+    check.process_metric(ref_gauge, config)
+
+    aggregator.assert_metric('prometheus.process.vm.bytes', count=0)
+
+
+def test_ignore_metrics_multiple_wildcards(
+    aggregator, mocked_prometheus_check, mocked_prometheus_scraper_config, text_data
+):
+    """
+    Test that metrics that matched an ignored metrics pattern is properly discarded.
+    """
+    check = mocked_prometheus_check
+    instance = copy.deepcopy(PROMETHEUS_CHECK_INSTANCE)
+    instance['_dry_run'] = False
+    instance['metrics'] = [
+        {
+            # Ignored
+            'go_memstats_mspan_inuse_bytes': 'go_memstats.mspan.inuse_bytes',
+            'go_memstats_mallocs_total': 'go_memstats.mallocs.total',
+            'go_memstats_mspan_sys_bytes': 'go_memstats.mspan.sys_bytes',
+            'go_memstats_alloc_bytes': 'go_memstats.alloc_bytes',
+            'go_memstats_gc_sys_bytes': 'go_memstats.gc.sys_bytes',
+            'go_memstats_buck_hash_sys_bytes': 'go_memstats.buck_hash.sys_bytes',
+            # Not ignored
+            'go_memstats_mcache_sys_bytes': 'go_memstats.mcache.sys_bytes',
+            'go_memstats_heap_released_bytes_total': 'go_memstats.heap.released.bytes_total',
+        }
+    ]
+    instance['ignore_metrics'] = [
+        'go_memstats_mallocs_total',
+        'go_memstats_mspan_*',
+        '*alloc*',
+        '*gc_sys_bytes',
+        'go_memstats_*_hash_sys_bytes',
+    ]
+
+    config = check.create_scraper_configuration(instance)
+
+    mock_response = mock.MagicMock(
+        status_code=200, iter_lines=lambda **kwargs: text_data.split("\n"), headers={'Content-Type': text_content_type}
+    )
+    with mock.patch('requests.get', return_value=mock_response, __name__="get"):
+        check.process(config)
+
+        # Make sure metrics are ignored
+        aggregator.assert_metric('prometheus.go_memstats.mspan.inuse_bytes', count=0)
+        aggregator.assert_metric('prometheus.go_memstats.mallocs.total', count=0)
+        aggregator.assert_metric('prometheus.go_memstats.mspan.sys_bytes', count=0)
+        aggregator.assert_metric('prometheus.go_memstats.alloc_bytes', count=0)
+        aggregator.assert_metric('prometheus.go_memstats.gc.sys_bytes', count=0)
+        aggregator.assert_metric('prometheus.go_memstats.buck_hash.sys_bytes', count=0)
+
+        # Make sure we don't ignore other metrics
+        aggregator.assert_metric('prometheus.go_memstats.mcache.sys_bytes', count=1)
+        aggregator.assert_metric('prometheus.go_memstats.heap.released.bytes_total', count=1)
+        aggregator.assert_all_metrics_covered()
+
+
 def test_label_joins(aggregator, mocked_prometheus_check, mocked_prometheus_scraper_config, mock_get):
     """ Tests label join on text format """
     check = mocked_prometheus_check

openmetrics/datadog_checks/openmetrics/data/conf.yaml.example

@@ -142,3 +142,13 @@ instances:
     ## Note: bearer_token_auth should be set to true to enable adding the token to HTTP headers for authentication.
     #
     # bearer_token_path: "<TOKEN_PATH>"
+
+    ## @param ignore_metrics - list of strings - optional
+    ## List of metrics to be ignored, the "*" wildcard can be used to match multiple metric names.
+    #
+    # ignore_metrics:
+    #  - <IGNORED_METRIC_NAME>
+    #  - <PREFIX_*>
+    #  - <*_SUFFIX>
+    #  - <PREFIX_*_SUFFIX>
+    #  - <*_SUBSTRING_*>