feat(profiling): Add --trace-profile flag

cmd/buildah/main.go

@@ -7,6 +7,7 @@ import (
 	"os/exec"
 	"runtime"
 	"runtime/pprof"
+	"runtime/trace"
 	"strings"
 	"syscall"
 
@@ -38,6 +39,8 @@ type globalFlags struct {
 	CPUProfile                 string
 	cpuProfileFile             *os.File
 	MemoryProfile              string
+	TraceProfile               string
+	traceProfileFile           *os.File
 	UserShortNameAliasConfPath string
 	CgroupManager              string
 }
@@ -105,6 +108,7 @@ func init() {
 	rootCmd.PersistentFlags().StringVar(&globalFlagResults.LogLevel, logLevel, "warn", `the log level to be used, one of "trace", "debug", "info", "warn", "error", "fatal", or "panic"`)
 	rootCmd.PersistentFlags().StringVar(&globalFlagResults.CPUProfile, "cpu-profile", "", "`file` to write CPU profile")
 	rootCmd.PersistentFlags().StringVar(&globalFlagResults.MemoryProfile, "memory-profile", "", "`file` to write memory profile")
+	rootCmd.PersistentFlags().StringVar(&globalFlagResults.TraceProfile, "trace-profile", "", "`file` to write trace profile")
 
 	if err := rootCmd.PersistentFlags().MarkHidden("cpu-profile"); err != nil {
 		logrus.Fatalf("unable to mark cpu-profile flag as hidden: %v", err)
@@ -118,6 +122,9 @@ func init() {
 	if err := rootCmd.PersistentFlags().MarkHidden("memory-profile"); err != nil {
 		logrus.Fatalf("unable to mark memory-profile flag as hidden: %v", err)
 	}
+	if err := rootCmd.PersistentFlags().MarkHidden("trace-profile"); err != nil {
+		logrus.Fatalf("unable to mark trace-profile flag as hidden: %v", err)
+	}
 }
 
 func initConfig() {
@@ -157,6 +164,16 @@ func before(cmd *cobra.Command) error {
 		}
 	}
 
+	if globalFlagResults.TraceProfile != "" {
+		globalFlagResults.traceProfileFile, err = os.Create(globalFlagResults.TraceProfile)
+		if err != nil {
+			logrus.Fatalf("could not create trace output file %s: %v", globalFlagResults.TraceProfile, err)
+		}
+		if err := trace.Start(globalFlagResults.traceProfileFile); err != nil {
+			logrus.Fatalf("could not start trace: %v", err)
+		}
+	}
+
 	defaultContainerConfig, err := config.Default()
 	if err != nil {
 		return err
@@ -219,6 +236,10 @@ func after(cmd *cobra.Command) error {
 			logrus.Fatalf("could not write memory profile %s: %v", globalFlagResults.MemoryProfile, err)
 		}
 	}
+	if globalFlagResults.TraceProfile != "" {
+		trace.Stop()
+		globalFlagResults.traceProfileFile.Close()
+	}
 	return nil
 }
 

tests/profiling.bats

@@ -0,0 +1,33 @@
+#!/usr/bin/env bats
+
+load helpers
+
+@test "trace-profile flag creates a valid Go trace" {
+  tmpfile="$TEST_SCRATCH_DIR/buildah-trace.$RANDOM.$RANDOM"
+  run_buildah info --trace-profile="$tmpfile"
+  assert "$status" -eq 0 "buildah info with --trace-profile should succeed"
+  [ -s "$tmpfile" ] || die "trace profile should not be empty"
+  run go tool trace -pprof=net "$tmpfile"
+  assert "$status" -eq 0 "go tool trace should succeed"
+  rm -f "$tmpfile"
+}
+
+@test "cpu-profile flag creates a valid CPU profile" {
+  tmpfile="$TEST_SCRATCH_DIR/buildah-cpu.$RANDOM.$RANDOM"
+  run_buildah info --cpu-profile="$tmpfile"
+  assert "$status" -eq 0 "buildah info with --cpu-profile should succeed"
+  [ -s "$tmpfile" ] || die "CPU profile should not be empty"
+  run go tool pprof -top "$tmpfile"
+  assert "$status" -eq 0 "go tool pprof should succeed on CPU profile"
+  rm -f "$tmpfile"
+}
+
+@test "memory-profile flag creates a valid memory profile" {
+  tmpfile="$TEST_SCRATCH_DIR/buildah-mem.$RANDOM.$RANDOM"
+  run_buildah info --memory-profile="$tmpfile"
+  assert "$status" -eq 0 "buildah info with --memory-profile should succeed"
+  [ -s "$tmpfile" ] || die "memory profile should not be empty"
+  run go tool pprof -top "$tmpfile"
+  assert "$status" -eq 0 "go tool pprof should succeed on memory profile"
+  rm -f "$tmpfile"
+}