update(falco_metrics): add kernel_event_counters_per_cpu_enabled config

Signed-off-by: Melissa Kilby <[email protected]>

Author: incertum

falco.yaml

@@ -1066,6 +1066,9 @@ syscall_event_drops:
 # counters reflect monotonic values since Falco's start and are exported at a
 # constant stats interval.
 #
+# `kernel_event_counters_per_cpu_enabled`: Detailed kernel event and drop counters
+# per CPU. typically used when debugging and not in production.
+#
 # `libbpf_stats_enabled`: Exposes statistics similar to `bpftool prog show`,
 # providing information such as the number of invocations of each BPF program
 # attached by Falco and the time spent in each program measured in nanoseconds.
@@ -1104,6 +1107,8 @@ metrics:
   resource_utilization_enabled: true
   state_counters_enabled: true
   kernel_event_counters_enabled: true
+  # Enabling `kernel_event_counters_per_cpu_enabled` automatically enables `kernel_event_counters_enabled`
+  kernel_event_counters_per_cpu_enabled: false
   libbpf_stats_enabled: true
   plugins_metrics_enabled: true
   convert_memory_to_mb: true

userspace/falco/configuration.cpp

@@ -581,6 +581,10 @@ void falco_configuration::load_yaml(const std::string& config_name)
 	{
 		m_metrics_flags |= METRICS_V2_KERNEL_COUNTERS;
 	}
+	if (m_config.get_scalar<bool>("metrics.kernel_event_counters_per_cpu_enabled", true))
+	{
+		m_metrics_flags |= METRICS_V2_KERNEL_COUNTERS_PER_CPU;
+	}
 	if (m_config.get_scalar<bool>("metrics.libbpf_stats_enabled", true))
 	{
 		m_metrics_flags |= METRICS_V2_LIBBPF_STATS;

userspace/falco/stats_writer.cpp

@@ -470,7 +470,7 @@ void stats_writer::collector::get_metrics_output_fields_additional(
 				m_writer->m_output_rule_metrics_converter->convert_metric_to_unit_convention(metric);
 			}
 			char metric_name[METRIC_NAME_MAX] = "falco.";
-			if((metric.flags & METRICS_V2_LIBBPF_STATS) || (metric.flags & METRICS_V2_KERNEL_COUNTERS) )
+			if((metric.flags & METRICS_V2_LIBBPF_STATS) || (metric.flags & METRICS_V2_KERNEL_COUNTERS) || (metric.flags & METRICS_V2_KERNEL_COUNTERS_PER_CPU) )
 			{
 				strlcpy(metric_name, "scap.", sizeof(metric_name));
 			}
@@ -600,7 +600,7 @@ void stats_writer::collector::collect(const std::shared_ptr<sinsp>& inspector, c
 			// Note: src is static for live captures
 			if (src != falco_common::syscall_source)
 			{
-				flags &= ~(METRICS_V2_KERNEL_COUNTERS | METRICS_V2_STATE_COUNTERS | METRICS_V2_LIBBPF_STATS);
+				flags &= ~(METRICS_V2_KERNEL_COUNTERS | METRICS_V2_KERNEL_COUNTERS_PER_CPU | METRICS_V2_STATE_COUNTERS | METRICS_V2_LIBBPF_STATS);
 
 			}
 			m_writer->m_libs_metrics_collector = std::make_unique<libs::metrics::libs_metrics_collector>(inspector.get(), flags);