Add ability to write "extra" stuff to stats file.

When run via scripts like run_performance_tests.sh, it's useful to
include extra info like the test being run and the specific program
variant to the stats file. So support that via the
environment. Environment keys starting with FALCO_STATS_EXTRA_XXX will
have the XXX and environment value added to the stats file.

It's undocumented as I doubt other programs will need this functionality
and it keeps the docs simpler.

test/run_performance_tests.sh

@@ -143,13 +143,13 @@ function start_subject_prog() {
 	if [ -z $RULES_FILE ]; then
 	    RULES_FILE=$SOURCE/../output/rules.yaml
 	fi
-	sudo $ROOT/test_mm -s $SOURCE/search_order.yaml -r $RULES_FILE > ./prog-output.txt 2>&1 &
+	sudo FALCO_STATS_EXTRA_variant=$VARIANT FALCO_STATS_EXTRA_benchmark=$live_test $ROOT/test_mm -S $SOURCE/search_order.yaml -s $STATS_FILE -r $RULES_FILE > ./prog-output.txt 2>&1 &
     elif [[ $ROOT == *"falco"* ]]; then
 	echo "   starting falco..."
 	if [ -z $RULES_FILE ]; then
 	    RULES_FILE=$SOURCE/rules/falco_rules.yaml
 	fi
-	sudo $ROOT/userspace/falco/falco -c $SOURCE/falco.yaml -r $RULES_FILE --option=stdout_output.enabled=false > ./prog-output.txt -A 2>&1 &
+	sudo FALCO_STATS_EXTRA_variant=$VARIANT FALCO_STATS_EXTRA_benchmark=$live_test $ROOT/userspace/falco/falco -c $SOURCE/falco.yaml -s $STATS_FILE -r $RULES_FILE --option=stdout_output.enabled=false > ./prog-output.txt -A 2>&1 &
     elif [[ $ROOT == *"sysdig"* ]]; then
 	echo "   starting sysdig..."
 	sudo $ROOT/userspace/sysdig/sysdig -N -z evt.type=none &
@@ -323,6 +323,7 @@ usage() {
     echo "   -r/--root: root directory containing falco/sysdig binaries (i.e. where you ran 'cmake')"
     echo "   -s/--source: root directory containing falco/sysdig source code"
     echo "   -R/--results: append test results to this file"
+    echo "   -S/--stats: append capture statistics to this file (only works for falco/test_mm)"
     echo "   -o/--output: append program output to this file"
     echo "   -U/--rules: path to rules file (only applicable for falco/test_mm)"
     echo "   -t/--test: test to run. Argument has the following format:"
@@ -342,7 +343,7 @@ usage() {
     echo "   -F/--falco-agent: When running an agent, whether or not to enable falco"
 }
 
-OPTS=`getopt -o hv:r:s:R:o:U:t:T: --long help,variant:,root:,source:,results:,output:,rules:,test:,tracedir:,agent-autodrop:,falco-agent: -n $0 -- "$@"`
+OPTS=`getopt -o hv:r:s:R:S:o:U:t:T: --long help,variant:,root:,source:,results:,stats:,output:,rules:,test:,tracedir:,agent-autodrop:,falco-agent: -n $0 -- "$@"`
 
 if [ $? != 0 ]; then
     echo "Exiting" >&2
@@ -356,6 +357,7 @@ ROOT=`dirname $0`/../build
 SOURCE=$ROOT
 SCRIPTDIR=`dirname $0`
 RESULTS_FILE=`dirname $0`/results.json
+STATS_FILE=`dirname $0`/capture_stats.json
 OUTPUT_FILE=`dirname $0`/program-output.txt
 RULES_FILE=
 TEST=trace:all
@@ -371,6 +373,7 @@ while true; do
 	-r | --root ) ROOT="$2"; shift 2;;
 	-s | --source ) SOURCE="$2"; shift 2;;
 	-R | --results ) RESULTS_FILE="$2"; shift 2;;
+	-S | --stats ) STATS_FILE="$2"; shift 2;;
 	-o | --output ) OUTPUT_FILE="$2"; shift 2;;
 	-U | --rules ) RULES_FILE="$2"; shift 2;;
 	-t | --test ) TEST="$2"; shift 2;;
@@ -405,6 +408,11 @@ if [ -z $RESULTS_FILE ]; then
     exit 1
 fi
 
+if [ -z $STATS_FILE ]; then
+    echo "An output file for capture statistics must be provided. Not continuing."
+    exit 1
+fi
+
 if [ -z $OUTPUT_FILE ]; then
     echo "An file for program output must be provided. Not continuing."
     exit 1

userspace/falco/statsfilewriter.cpp

@@ -11,6 +11,8 @@ static void timer_handler (int signum)
 	g_save_stats = true;
 }
 
+extern char **environ;
+
 StatsFileWriter::StatsFileWriter()
 	: m_num_stats(0), m_inspector(NULL)
 {
@@ -48,6 +50,30 @@ bool StatsFileWriter::init(sinsp *inspector, string &filename, uint32_t interval
 		return false;
 	}
 
+	// (Undocumented) feature. Take any environment keys prefixed
+	// with FALCO_STATS_EXTRA_XXX and add them to the output. Used by
+	// run_performance_tests.sh.
+	for(uint32_t i=0; environ[i]; i++)
+	{
+		char *p = strstr(environ[i], "=");
+		if(!p)
+		{
+			errstr = string("Could not find environment separator in ") + string(environ[i]);
+			return false;
+		}
+		string key(environ[i], p-environ[i]);
+		string val(p+1, strlen(environ[i])-(p-environ[i])-1);
+		if(key.compare(0, 18, "FALCO_STATS_EXTRA_") == 0)
+		{
+			string sub = key.substr(18);
+			if (m_extra != "")
+			{
+				m_extra += ", ";
+			}
+			m_extra += "\"" + sub + "\": " + "\"" + val + "\"";
+		}
+	}
+
 	return true;
 }
 
@@ -73,8 +99,12 @@ void StatsFileWriter::handle()
 			delta.n_preemptions = cstats.n_preemptions - m_last_stats.n_preemptions;
 		}
 
-		m_output << "{\"sample\": " << m_num_stats <<
-			", \"cur\": {" <<
+		m_output << "{\"sample\": " << m_num_stats;
+		if(m_extra != "")
+		{
+			m_output << ", " << m_extra;
+		}
+		m_output << ", \"cur\": {" <<
 			"\"events\": " << cstats.n_evts <<
 			", \"drops\": " << cstats.n_drops <<
 			", \"preemptions\": " << cstats.n_preemptions <<

userspace/falco/statsfilewriter.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <fstream>
+#include <string>
+#include <map>
 
 #include <sinsp.h>
 
@@ -25,6 +27,6 @@ protected:
 	uint32_t m_num_stats;
 	sinsp *m_inspector;
 	std::ofstream m_output;
-
+	std::string m_extra;
 	scap_stats m_last_stats;
 };